Note: Descriptions are shown in the official language in which they were submitted.
ANTIBACTERIAL AOENT
The present invention provides for the stereo-
selective total synthesis of certain novel substituted
'3-1,4-morpholine-2-carboxylic acids possessing a fused
~-lactam ring in the 1,6-position and carrying a substituent
cis to carbon 5 in the 7-position of the fused ring system
represented by the general formula
H H
X~ 0 4
'1
C02H
wherein Q is hydrogen, alkyl, aralkyl or -CH2COOZ
where Z is hydrogen or the residue of an ester group
and X is azido, amino or acylamino. When X is acyl-
amino, these acids (and their pharmaceutically accept-
a~le salts and physiologically hydrolyzed esters) are
potent antibacterial agents.
Also included in this invention are various
novel intermediates useful in preparing the active ~-lactam
derivatives described above and various processes for
the production of the intermediates and active compounds.
- 1 -
The compounds having the above general formula
represent a new family of ~-lactam antibiotics. They
can be considered nuclear analogs of cephalosporins in
which the sulfur atom of the dihydrothiazine ring is
replaced by an oxygen atom and shifted from position
5 to position 4 of the ~lactam ring system as numbered
in the formula above.
However, since Sheehan has used the term o-cepham
for the structure
8~2
N 3
O-Cepham
[J.C. Sheehan and M. Dadic, J. Heterocyclic Chem., 5,
770 (1968)], we propose the use of the term 0-2-isocepham
for the basic system having the formula
~O 2
~ N ~/ 3
0 4
The numerical prefix indicates the position of the
hetero-atom.
There is thus provided by the present invention
, the novel 0-2-isocephem compounds having the formula
~2
R _ ~ H / C
~ I ' I
0~ \ ~ ~Q
~0 H
wherein R is sn acyl group and Q is hydro~en, alkyl,
~ralkyl or -CH ~O~Z in which Z is hydrogen or the residue
of ~n ester group ~nd easily cleavable esters and
ph8rmaceutical~y acceptable salts thereof.
The acyl group ~ can be chosen from a wide ~ar~ety
of organic acyl radicals which yield products of
~mproved properties and is preferably an acyl radical
which ~s contained in a naturally occurring or bio-
~ynthetically, semi-synthetically or totally-synthet-
icslly act~ve N-acyl der~vative of 6-aminopen~cillanic
8cid or 7-aminocephalosporanic acid. Examples of
8uitable ~cyl groups are de~inPd in the follow~ng
general formulae, but it should be noted that this
18 nG~ ~ntended to be an exhaust~ve list of all the
possible aryl grG~p.~ which may be used.
(~) RaC~H2nCO- ~
w~ere Ra is aryl (carbocyclic or heterocyclic), sub-
8tituted ~ryl, cycloalkyl, substi~uted cycloalkyl,
~ 4~ ~
cycloalkenyl, substituted cycloalkenyl or a nonaromatic
or mesoionlc heterocyclic group, and n is an ~ntege~
from 1-4. The preferred Ra substituents are (a) aryl
selected from phenyl~ 2-thienyl, 3-thienyl, furyl, 4-
i~oxazolyl, pyridyl, tetrazolyl, sydnone-3 or -4,
imidazolyl, naphthoyl, quinoxal~nyl, triazolyl, iso-
thl~zolyl, thiadiazolyl, thiazolyl, oxazolyl, oxadiazolyl,
pyrazolyl, furazan, pyrazinyl, pyrimidinyl, pyridazi~yL
or triazinyl; (b) substituted aryl in which the aryl
groups mentioned above under (a) are substitueed by
one or more radicals selected from chloro, bromo, iodo,
f}uoro, nitro, ami~o, cyano, (lower)~lkanoyloxy, tlower)-
alkanoyl, ~lower)alkoxyamino, ~lower)alkoxy, (lower)-
~lkyl, (lower)alkyla~ino, hydroxy, guanidino, (lower)-
alkylthio, carboxy, phenyl, haloph~nyl, trifluoromethyl,
di(lower)alkylamino, sulfamyl, (lower)alkanoylamino,
phenyl(lower)alkylamido, cycloalkylamino, ~llylamido
rpholinocarbonyl, pyrrolidinocarl~onyl, piperidinocar^
bonyl, tetrahydropyridino, furfurylamido or N-alkyl-N-
~nilino; (c) C3-C12 cycloalkyl; (d~ substituted C3-C12
cycloalkyl where the substituents are one or more radicals
~elected from chloro, bromo, fluoro, iodo, nitro, trifluoro-
methyl, Cl-C4 alkyl, Cl-C4 alkylamino, Cl-C~ alkoxy or
amino; (e) C3-C12 cycloalkenyl, said cycloalkeny, group
hsving 1 or 2 double bonds; and ~f~ substituted C3-C12
~ 34~ ~
cyclo~lkenyl, said cycloalkenyl group having 1 or 2
double bonds and being substi~uted by one or more
radicals selected from chloro, bro~o, fluoro, iodo,
nitro, tr~fluoromethyl, Cl-C4 alkyl, Cl-C4 alkylamino,
Cl-C2 alkoxy or amino. The most preferred Ra groups
are phenyl; phenyi ~ubst~tuted by one or more radic21s
selected from chloro, bromo, ~odo, fluoro, nitro, amino,
(lower)alkyl, guanidino, (lower)alkylthio, cyano, (lower)-
ilkoxy, sulfamyl, (lower)alkylamino, hydroxy, acetoxy,
or tri~luoromethyl; 2-thienyl; 3-thienyl; tetrazolyl;
8ydnone -3; sydnone -4; furyl; isothiazolyl; thiadiazolyl
optionally substituted with phenyl; oxadiazolyl optionally
8ubstituted with phenyl; thiazolyl; imi~azolyl; triazolyl;
oxazolyl; pyridyl; furazan optionally substituted at the
3-position with methoxy; 4-isoxazolyl optionally sub-
~tituted at the 5-position with methyl and at the 3-posi-
tion with phenyl or halopnenyl; 1,4-cyclohexadienyl;
l^cyclohexenyl and l-aminocyclohexyl.
The most preferred ~cyl groups of this category
are those in which n is 1. Examples of this category
include phenylacetyl, halophenylacetyl, nitrophenyl2cetyl,
~minophenylace~yl, ~-~o-aminomethylphenyl3propionyl,
~lower)alkanoyloxyphenylacetyl (e.g. acetoxyphenylacetyl3,
(lower)alkoxyphenylacetyl (e.g. methoxyphenylacetyl,
ethoxyphenylacetyl~, ~lower)alkylphenylacetvl ~e.g. methyl-
ph nylacetyl or ethylphenylacetyl), hydroxy~henylacet~l
(e~g. o-hydroxyphenylacetyl), (lower)alkylami~ophenyl-
acet~ . o~ or a- amin~ethy~ phenvl~c~ty~
m- or p- guanidinophenylacetyl, o-carboxyphenylacetyl,
N,N-~is-(2-chloroethyl)aminophenylpropionyl, thien-2
and 3-ylacetyl, 2- or 3- furylacetyl, 1,2,5-thiadiazole-
3-acetyl, isothiazolyl-4-acetyl, 4-lsoxazolylacetyl,
l-cyclohexenylacetyl, 2-aminomethyl-1-cyclohexenyl-
acetyll l-sminocyclohexylacetyl, 1,4-cyclohexadienyl-
acetyl, 2-aminomethyl-1,4-cyclohexadienylacetyl,
pyridylacetyl, tetrazolylacetyl (other heeerocyclic
groups of this type are d~srlosed in U.S. 3,819,623
and 3,516,997) or a sydnoneacetyl group as disclosed
~n U.S. 3,681,32~, 3,530,123 and 3,563,983. Other
groups of this type include 3-phenyl-5-chlorophenyl-
5-me~hylisoxazol-4-ylacetyl and 3-~2,6-di~hlorophenyl)-
5-methylisoxazol-4-ylacetyl or a group in which isox-
- azolyl is replaced by isothiazole as disclosed in U.S.
3,551,440. Still other examples are o-, m- and ~-
(2l-aminoethsxy~phenylacetyl (as disclosed in U.S.
3, 75~ j 905) J 4,5-dimethoxycarbonyl-1,2,3-tria~ol-1-
yl~cetyl or 4-cyano-1,2 ,3-triazol-1-yl-acetyl (as
d~scl~sed in U,S. 3,821,2~6) and ~midazol-(l)-acetyl
t~s di.sclos~d ~n ~.S. 3,632,B10;
(ii) CnH2n~lCO -
where n is an integer from 1-7. The alkyl group may
be strsight or branched and, ~f desired, may be inter~
rupted by an oxygen or sulphur atom or substituted by,
e.g., a cy~no group. Examples of this group include
cyanoacetyl, valeryl, hexanoyl, heptanoyl, ethoxy-
carbonyl, octanoyl and butylthio~cetyl. A preferred
acyl group is cyanoacetyl;
(iii) CnH2n-1C~)~
where n is an integer from 2-7. The alkenyl group
may be straight or branched and, if desired, may be
~nterrupted by an oxygen or sulphur atom. An example
of this group is allylth$oscetyl;
(iv) Rb
Ra-O-l~C~_
RC
where Ra i8 as defined under (i) and in addition may
be benzyl, Cl-C6 al~yl or (lower)alkoxycarbonyl and
Rb and Rc which may be the same or different each
repre~ent hydrogen, phenyl, benzyl, phenethyl or Cl-C6
81kyl. The prefe~red Ra 6ubst~tu~nts ln this cat~gory
are ~enzyl, Cl-C6 al~yl, (lower~alkoxycarbonyl and those
mentioned under (i) as being preferred aryl, subst~u~ed
~ryi, cycloalkyl (and subst~tuted eyc~oalkyl) 3nd
cycloalkenyl (and substltuted cycloalkenyl) groups.
The most preferred Ra group is phenyl~ Examples of
~his group lnclude phenoxyacetyl, 2-phenoxy-2-phenyl-
acetyl~ 2-phenoxypropionyl, 2-phenoxybutyryl, benzyloxy-
~cetyl, 2-methyl-2-phenoxypropionyl, p-cresoxyacetyl,
p-methylthiophenoxyacetyl and ethoxycarbonylacetyl;
(v) Rb
R~S-C-~O-
RC
where Ra is as defined under ~i) and in add~tion may be
~enzyl or Cl-C6 alkyl and Rb and Rc have the meanings
defined ~nder (iv). The prcferred Ra suhstituents in
thi8 category are benzyl, Cl^C6 alkyl and those mentioned
under (i) as belng:preferred aryl, substituted aryl,
cyclosl~yl (and substituted cycloalkyl) and cyclo-
alkenyl ~and substituted cycloalkenyl) groups. The
most preferred aryl groups of this type are those in
which Rb and Rc are hydrogen and Ra is phenyl; phenyl
~ubstituted with one or more radicals selected from
chloro, bromo, iodo, fluoro, nitro, amino, (lower)-
alkyl, (lower)alkythio, cyano, (lower)alkoxy, (lower~-
alkylamino, hydroxy, acetoxy or trifluoromethyl;
3-pyr~dyl; or 4-pyridyl;
(v~) RaX (CH2)mCO-
where Ra ls ~s deflned under (i) and in addition may
be benzyl, X is oxygen or sulphur and m ;.s an integer
from 2-5. The prefer~ed Ra groups ar~ ben yl and those
mentioned under (i) as being preferred aryl, substituted
sryl, cycloalkyl ~and substituted cycloalkyl) and
cycloalkenyl (and s~bstituted cycloalkenyl) groups.
--8--
An example of this group is S-benzylthiopropionyl.
- (vii) RaCO- . .
where Ra is as defined under (i). The preferred Ra
group~ are those mentioned under (i~ as being prefe~red
ar~l, s~bstituted aryl, cycloalkyl (and su~stituted
cycloalkyl) and cycloalkenyl (and substituted cyclo-
alkenyl) groups. The most preferred aryl groups of
this category are those ~n which Ra is phenyl; phenyl
subst~tuted with one or more radicals selected from
chloro, bromo, iodo, fluoro, nitro, amino, (lower)-
slkyl, (lower)alkylthio, cyano, (lower)alkoxy, (lower)-
alkylamino, di~lower)al~ylamino, hydrnxy, acetoxy or
trifluoromethyl, and most preferably phenyl substituted
at the 2-position by carboxy or phenyl or at the 2- and
6-positions by methoxy; 2-ethoxynaphthoyl; 3-phenyl-
5-methylisoxazol-4^yl; 3-o-chlorophenyl-5-methylisoxazol-
- 4-yl; 3-(2,6-dichlorophenyl)-5-methylisoxazol-4-yl and
l-aminocyclohexyl. Examples of this group include 2,6-
dimethoxybenzoyl, benzoyl, 2-biphenylcarbony~, 2-amino-
~ethylbenzoyl, 2-carboxybenzoyl-2-phenylbenzoyl, 2-
thienylcarbonyl, 3-thienylcarbonyl and 2-chloro~enzoyl;
(v~ ii)
Ra-CX-CO- or Ra-CH-CH2CO-
where Ra is as defined under (i) and Y is hydrazino,
guanldino, ureido, thioureido and substituted thioureido
(~ disclosed in U.S. 3,741,962), allophanamido (as
de~cr~bed in U.S. 3,483,188), 3-guanyl-1-ureido~ as
6~
in U.S. 3,796,709), 3-(2-furoyl)ureido, cyanamino (as in
U.S. 3,796,709), 3-(benzoyl)ureido, azido, amino, acyl-
'`t amino (e.g. carbobenzoxyamino), a group obtained by
reacting the amino group of the 7-side chain with an
aldehyde or ketone (e.g. acetone, formaldehyde, acetalde-
hyde, butyraldehyde, acetylacetone, methyl acetoacetate,
- benzaldehyde, salicylaldehyde, methyl ethyl ketone or
ethyl acetoacetate), hydroxy, etherified hydroxy,
esterified hydroxy, carboxy, esterified carboxy (as
disclosed for example in U.S. 3,282,926, 3,819,601 and
3,635,961 and including especially
.
,, ,~ .
-C - O ~ / \ ~ ), triazolyl,
\=/ ':
:
tetrazolyl, cyano, halogeno, acyloxy (e.g. formyloxy
or (lower)alkanoyloxy), sulfo, sulfoamino or esterified
sulfo. The preferred Ra substituents are those mentioned
under (i) as being preferred aryl, substituted aryl,
cycloalkyl (and substituted cycloalkyl) and cycloalkenyl
(and substituted cycloalkenyl~ groups. Preferred Y
substituents are hydrazino; guanidino; ureido; substi-
tuted thioureido of the formula
-NH-C-N /
S Rq
in which RP is hydrogen or Cl-C8 alkyl and Rq is hydrogen,
-- 10 --
g~
Cl-Cg alkyl, G~-Cg alkenyl, phenyl, benzoyl, Cl-C8
alkoxy- Cl-C8 alkyl, (carbo-Cl-C~ alkoxy) Cl~C8 alkyl;
allophanamido; 3-guanyl-1-ureido; 3-(2-furoyl)ureido;
3-(benzoyl)ureido; azido; amino; a group o~tained by
reacting the amino group Y with acetone, formaldehyde,
acetaldehyde, butyraldehyde, acetylacetone, methyl
acotoacetate, benzaldehyde, salicylaldehyde, methyl
ethyl ketone or ethyl acetoacetate; hydroxy; etherified
hydroxy including especially (lower)alkoxy; carboxy;
esterifled carboxy includin~ especially 5-indanyloxy-
cflrbonyl; tria~olyl, tetrazolyl; cvano; cyanamino;
halogeno; formyloxy; (lower)alkanoyloxy; ~sulfo; or
sulfoamino. Examples of this group inclu~e a-amino-
phenylacetyl; ~-carboxyphenylacetyl; 2,2-dimethyl-5-oxo-
4-phenyl-1-imidazolyl; a-amino-p-hydroxyphenylacetyl;
a-hydroxyphenyl~cetyl; a-formyloxyphenylacetyl and other
aryl groups of this type disclosed in U.S. 3,812,116 and
3,821,017; ~-amino-~-2- or 3-thienylace~yl; a-flmino-a-
(3-chloro-4-hydroxy)phenylacetyl; a-amino-a-(1,4-cyclo-
hexadienyl)acetyl; a-azidophenylacetvl; ~-amino-~-(l-
cyclohexenyl)acetyl; 2-carboxy^a-3-thienylacetyl; ~-amino-
~-~3,S-dichloro-4-hydroxyphenyl)acetyl; -amino-a-3- or 4-
or 5-isothiazolylacetyl (as in U.S. 3,S79,506) and other
a-~mino and a-hydroxy-heterocyclylacetyl groups as
disclosed for example in U.S. 3,821,2~7,
1~13~b
(ix) Re
Rd-¦-co_
where Rd, ~e and Rf which may be the same or different
may each represent Cl^C6 alkyl, phenyl or substituted
phenyl. The prefe.red phenyl substi~uents are one or
mnre rsdicals selected from chloro, bromo, iodo, fluoro,
trlfluoromethyl, nitro, amino, cyano, (lower)alkanoyloxy,
(~ower)alkanoyl, (lower)alkoxyamino, (lower)alkoxy,
(lower)alkyl, (lower)alkylamino, hydroxy, (lower)alkyl-
thio, carboxy, di(lower)alkylamino or sulfamyl. An
example of this group ~8 triphenylmethylcarbonyl.
(x)
Ra_NH_C_
where Ra is ~s defined under (i) and in addition may be
hydrogen, Cl_c6 alkyl, halogen substituted Cl-C6 alkyl,
henethyl, phenoxymethyl; benzyl or Ra-~C- ~nd X is oxygen
' O
or su~phur. An example of such a group is Cl(C~2)~N~CO;
(x~
CH2
(C\2)n /C\ O-
`C:H2 Y
where Y ~s as def~ned under (viii) and n is an integer
o~ 1 4. A most preferred Y substituent is amino. An
example of this group is l-aminocyclohexanecarbonyl.
b
(xii) Aminoacyl, for example
2 2 n
where n is an integer of 1-10, or
H2N-CnH21,Ar (CH2)mCO
where m is zero or an integer from 1-10, and n is
0, 1, or 2; Rg is hydrogen or an alkyl, aryl, aralkyl
or carboxy group ~r a group as defined under Ra in
~ bo~e; snd Ar ifi an arylene ~roup, e.g. p-phenylene
or 1,4-naphthylene. Preferred aryl groups of the above
formulae are those in which Rg iB hydrogen, (lower)-
slkyl, phenyl, benzyl or carboxy and Ar is p-phenylene
or 1,4-naphehylene. Examples of such gro~ps are
di~closed in U.K. 1,054,806. Examples of groups of
this type include p-aminophenylacetyl and J-aminoadipoyl
derived from naturally occ~rring amino 3cids and deriv-
~tives thereof, e.g. N-benzoyl-~ -aminoadipoyl;
~ xiii) Substituted glyoxylyl groups of the
formula
~ h~CO~CO-
where Rh is an aliphatic, araliphatic or aromatic group.
The preferred Rh groups are 2-thienyl; 3-thienyl;
a-naphthyl; 2-phenanthryl or a mono-, di- or tri-
8ubst~tuted phenyl group, the su~stituents b~ing
~elected from chloro, bromo, iodo, f luoro, amino,
di(lower)alkylamino, (lower)aikyl, (lower)alkoxy,
nitro or ~lower)alkanoylamino. Exampl es of chis category
~re disclosed in U.S. 3,546,219 and 3,573,294. Included
in this group are also the ~-carbonyl derivatives of the above
substituted glyoxylyl groups formed for example with hydroxyl-
amine, semicarbazide, thicsemicarbazide, isoniazide or hydrazine;
(xiv) Ra-CH-CO-
NH
X = C
H-N-C-R
X'
where Ra has the meaning defined under (i), X is oxygen or sul-
I phur, X' is oxygen or imino and Ri represents (lower)alkyl,
¦ cycloalkyl having 4,5,6 or 7 carbon atoms, monohalo(lower)alkyl,
dichloromethyl, trichloromethyl, (lower)alkenyl of 2-6 carbon
I atoms,
~ ~ (CH2)n- ~ ~ (CH2jn , ~
23 1 / ~ N~ ~ ~\ , n
~ ~ " ~ N 3` oJ
R ~ _ I _ k
"/ ~ ~ ~ ; ,~ ~
-- l -t
H3C
~ O CH3
n is an integer from O to 3 inclusive and eac~ of Rk
and ~ is hydrogen, nitro, di(lower)alkylamino, (lower)-
alkanoylamino, (lower)alkanoyloxy, Cl-C6 alkyl, Cl-~6
alkoxy, sulfamyl, ehloro, bromo, iodo, fluoro or tri-
fluoromethyl. The preferred Ra substituents are those
mentloned under (i) as being preferred aryl, substituted
aryl, cycloalkyl (and substituted cycloAlkyl) and
cycloalkenyl (and substituted cyeloalkenyi) groups.
Preferred acyl groups of this type are those in which
Ra is 2-thienyl; 3-thienyl; phenyl; or phenyl sub-
stituted by one or more radicals selected from nitro,
ditlower)alkylamino, (lower~alkanoylamino, amino,
hydroxy, (lower)alkanoyloxy, Cl-C6 alkyl, Cl-C6 alkoxy,
~ulfamyl, chloro, bromo, iodo, fluoro or trifluoro-
methyl; ~ is oxygen; X' is oxygen or imi~o and Ri is
~lower~al'~yl, p~enyl, 2-thienyl, 3-~hienyl, 2-furyl
or 5-nitro-2-furyl. The most preferred groups are
those of the above formula where Ra is phenyl, p-hydroxy-
phenyl, 2-thienyl or 3-thienyl; X is oxygen; X' is
oxygen, and Ri is phenyl or 2-furyl. Exa~ples are
~isclosed in U.S. 3,687,949 and 3,646,024;
~i~13~
~XV)
Ri Ra~ ct~_
, 11 ,~ NH .
N~o
~IB2-CO-
R~ . N
~ ~ or. Rl- ~ NH-CE2CO-
where Ra has the meaning defined in (~) ~nd Ri has
the meaning defined in (xiv). The preferred Ra
substituents are those mentioned under (i) as being
preferred aryl, substituted aryl, cycloalkyl (and
subst~tuted cycloalkyl) and cyeloalkenyl
(and substituted cycloalkenyl) group~. Preferred Ri
substituents ~nclude (lower)alkyl, dichloromethyl,
C4-C7 cycloalkyl, 2-thienyl, 3-thienyl, phenyl,
benzyl, halobenzyl,
N~c3
~;;3 f~N3 ~
C6H5 ~ and ~ C6H5
Examples of this group are disclosed in U.S. 3,626~024
and 3,692,779;
(xvi)
Ra-CH_CQ_
S -C rRl
B
where Ra has the meaning defined in {i) and Rl is (lower)-
alkyl, C3-C12 cycloalkyl, aryl (especislly phenyl), a
monocyclic heterocyclic radical ha~ing 5 or 6 atoms
exclus~ve of hy~rogen which are C, S, N or 0, no more
than 2 atoms being other than ~, or a substituted mono-
cyclic heterocyclic radical as defined above having
one or more substituents selected from halo, ~lower)-
~l~yl, (lower)alkoxy or phenyl. Examples of this group
are dLsclosed in U.S. 3,778,436. Most preferred
groups are (lower)alkyl, phenyl, thienyl or furyl.
. A preferred cla~ of acyl groups are those of the
formula
Ar ~-C~-C-
~ 3~ ~
wherein Ar' is a radical of the formula
Rm Rm
R
R
in wh~ch Rm, Rn and R are alike or dif~erent and each
~8 hydrogen, hydroxy, (l~wer)al~y1, cyano, ~lower)al~oxy,
chloro, bromo, iodo, f~uoro, trifluoromethyl, nitro,
~mino, (lower)alkylamino, di(lower)alkylamino, (lower~-
al~anoyl, (lower3alkanoylo~y such as p-acetoxy or phenyl
~nd Y is amino or a group obta~ned by reacting the amino
group wlth acetaldehyde, formaldehyde or acetone, fluoro,
chloro, bromo, iodo, hydroxy, (lower)al~anoyloxy, carbo~y,
guan~dino, 3-guanyl-1-ure~do, 3-~2-furoyl)ureido, 3-ben20yl-
ureido, sulfo, sulfoamino, ureido, thioureido, (lower)-
~koxy, cyano, cyanamino or indanyloxycar~onyl. Part~-
sularly preferred Ar radicals are ph~nyl, p-hydro~yphenyl,
. 4-hydroxy-3,5-dichlorophenyl, 3-chloro-4-hydr~xyp~enyl,
o-, ~- cr p- amin~methylphenyl, 2-thienyl, 3- hienyl,
l-cyclohexenyl and 1,4-cyclohexadienyl. P2rt~c~larly
preferred Y groups are amino, hydroxy and carboxy.
8et forth bel~w are formulae of the most preferred acyl
groups of ~his class:
'
co~ o~CH~CO~;
-18- j
~13gS~ ' '
Cl CH-'O- ;iiO;~CN-CO'
C~-CO-
NH2 ;~3~H -CO-
NH~
C3- CH-CO~ CH-CO- ;
~C~-CO- ;
OH
C~-CO-
L CH-CO-
OH
H-CO- ; ~CH-CO-
(~ CH-CO- ~7 C~
COOH ~ S
CH-CO- ; ~ 7H-CO- ;
COOH COOH
H-CO snd ~ CH-CO-
C- O
' ' ~\/~ .
Of most interest are the acyl groups of the above class
where the acid ArCH(X)COOH is of the D-series.
- Other particularly preferred acyl groups for the
compounds of formula I are
oc~3
N i C-CH2Ct)- ; ~CO-
H3
N N
- ! c~ N~SCH2CO-;
~[ co-;
V ~ C~3
wh2re U and V are ~like or different and esch $s
hydrogen, ch~oro o~ fluoro;
-20-
~CH2CO- ~--CH2CO-
~CH2CO~ CH2CO-
N~
ll C-CH2~0- , /--\ '
N~ / ~ Cll-t:O-
O=C~ C=O
C6~5
OCH2CO- , <~SCH2CO- '
CH2NH2
2C- , Cl-C7 alkyl-CO-
' ~CO- l ~C~2Co_
~J_ , ~CH2CO-
~H2~0- , N~N
--2~. -
r~
Cl-C7 alkoxy-Co- ~ 2 .
~CH2~CI-NH-CH2CO-, ~OCH2NHCO-
OH
O--C--I--H ~--CH2CO- ,
, . N/
- COOH C6~S
~CO- , ~ CO- .
C~2NH2
' '' ~ ' ' ~SC~2CO- " ~
- and
.
--2~--
DIV. III
b
Thus this divisional application provides a process
for preparing a 7-amino 0-2-isocephem intermediate of the
formula
H H
VII ~ N ~ W
CO 2
wherein W is hydrogen, (lower)alkyl of 1 to 10 carbon atoms,
aralkyl, or -CH2COOZ where Z is hydrogen or Cl-C6 alkyl; and
R" is hydrogen or an easily cleavable ester selected from the
group consisting of benzhydryl, benzyl, p-nitrobenzyl,
p-methoxybenzyl, trichloroethyl, trimethylsilyl, phenacyl,
acetonyl, (lower)alkyl, triphenylmethyl, methoxymethyl, indanyl,
phthalidyl, pivaloyloxymethyl and acetoxymethyl, or a salt
thereof; which process comprises selectively reducing a 7-azido
intermediate of the formula
H H
~N
Va
CO2
wherein W is as defined above, R' is an easily cleavable ester
carboxyl-protecting group and, if desired, removing protecting
group R' by methods known ~ se to produce the corresponding
free acid intermediate of formula VII and, if desired, convert-
ing the free acid form of intermediate VII to a salt thereof
by methods known per se. In a preferred embodiment the 7-a2ido
intermediate is reduced by catalytic hydrogenation with a
catalyst selected from palladium, platinum, palladium oxide,
- 22(a) -
DIV. III
~1134t~6
:
platinum oxide or Raney nickel, said cataly~t being optionally
supported on a carrier, or by chemical reduction with a
reducing agent selected from zinc and ammonium chloride or
hydrogen sulfide and triethylamine. Preferably W is (lower)-
: alkyl of 1 to 10 carbon atoms.
- 22(~) -
,, ~,
The term "(lower)alkyl" as used herein means
both stralght and branched chain alipha~ic hydrocarbon
radicals havlng from one to ten carbon atoms such as
methyl, ethyl, propyl, isopropyl, butyl, isobutyl, t-
bu~yl, ~myl, hexyl, 2-ethylhexyl, heptyl, decyl, etc.
Similsrly, where the term "(lower)" is used as part
of the description of anot~er group, e.g. "(lower)-
alkoxy", it refers to the alkyl portion of such group
whlch is therefore described above in connection
with "(lower)alkyl".
~ he pharmaceutically acceptable salts referred
to abo~e include the nontoxic car~oxylic acid salts,
e.g. nontoxic metallic sslts such as sodium, potassium,
c~eium and aluminum, the ammonium salt and salts with
nontoxic amlnes, e.g. trialkylamines, proca ine,
dibenzylamine,. N-~enzyl~ -phenethylamine, l~ephenamine,
N,N'-dibenzyle~hylenediamine, N-alkylpiperidine and
other ~mines which have bee~ used to form salts of
penicillins and cephalosporins. When a basic group
ig present, as when it occurs in the 7-acyl group,
the present invention al50 ~ncludes the pharmaceutically
~ccepta~le acid sddition salts, e.g. salts with mineral
acids ~uch as hydrochloric, hydrobrom~c, hydroiodic,
pho~phorlc, sulfuzic and salts with org~nlc acids such
~ leic, acetic, citric, oxalic, succinic, be~20ic,
t~rtar~c, fum2ric, mandel~c~ asco~bic and m~lic. The
term ;'pharmaceutically acceptable salts" is also
me~t to include nontox~c acid addition salts of
the easily cleav~ble esters referred to a~ove. The
compounds which contsin a basic group in radical
a may also be present in the form o an internal
salt, i.e. in the form of the zwitterion.
The easily cleavable esters referred to above
lnclude ester groups which are removable by methods,
e.g. chemical or enzymatic hydrolysis, treatment with
chemi~al reducing agents under mild contitions,
irradistion with ultraviolet light or catalytic
hydrogenation, which do not result in any appreciable
destruction of the rem~ining portion of t~e molecule.
Examples of suitable esters include thos~ disclosed
~n U.S. Patents 3,284,451 and 3,249,62? and U.K.
Patents 1,229,453 and 1,073,530. Esters which have
been used previously in penicillin and cephalosporin
chemlstry include for example benzhydryl, p-nitrobenzyl,
benzjl, trichloroethyl, s~lyl s~ch as trimethyls~lyl,
phenacyl, p-methoxybenzyl, &cetonyl and
(lo~er)alky~ such 85 methyl, ethyl and t-butyl.
Partlcularly preferred easily cle~vable esters are
those which ar~ hydrolyzed under physiological condi-
t~on~ such as pivaloyloxymethyl, acetoxymethyl and
~eth~xymethyl.
As the 0-2-isocephem compounds of the pre6ent
invention m~y possess one o~ more a~ymmetric carbon
-24-
atoms, the invent~n include~ all of the possible
enantiomeric and diastereomeric forms of the com-
pound~ of the general formula I shown sbove.
Resulting mixtures of isomers can be separated lnto the
ind~vidual isomers according to methods which are
known per se, e.g. fractional crystsllization,
.
adsorption chromatography or other suitable separation
processes. ~esulting racemates can be separated into
the ~ntipodes in the usufll m~nner after introduction
of suitable sslt-forming groupings, e.g.by forming
a mixture of diastereoisomeric salts w$th optically
active salt-forming agents, separating the mixture
into diastereo~somerlc salts, and converting the
~eparated salts into the free compounds, or by
frActiona~ crystallizat~on from optically active
801vents
It w~ll be appreciated that certain of the
compounds of this invention exist in various states
of so~vatlon and the anhydrous as well as solvsted
forms are within the scope of the invention.
The free acid compounds of the above general formula
I where R is acyl snd physiolo~ically hydrolyzed
e~ters thereof together wi~h the pharmaceutically
acceptable salts of such free acids and ~sters are
active antibacterial agents. The remaining compounds
o~ the ~bove general formula I including salts thereof
-25-
----
are valuable intermediaees which can be converted
into the above-ment'~onet pharm~cologically active .
c~mpounds in a simple manner, for example, as
de8c~ibed below.
P~eferred embodiments of the present ~nvention
~re the 0-2-isoceph~.m compounds having the formula
H
o~ tl~ w
~2~
wherein W is hydrogen, alkyl, e.g. methyl, or aralkyl,
e.g. benzyl or phenethyl and R represents an acyl group,
and easily cleavable esters and pharmaceutically
acceptable salts thereof.
Preferred acids, esters and salts of formula II are
those in whi.ch acyl group R is selected from the acyl
groups defined above under (i) to (xvi). The acyl groups
mentioned as being preferred groups within categories (i)
to (xvi) are also preferred in ~he compounds defined by
gener~l formula II.
More preferred acids, esters ~nd salts of formula
II are thos~ in which acyl g~oup R ls
Ar'-~-C0-
y
ln which Ar' is a radical o~- the formula
R Rm
Rn ~ or
E~.
in wh~ch Rm, Rn snd R are alike or different and each
iB hydrogen, hydroxy, (lower)alkyl, cyano, (lower)alkoxy,
chloro, bromo, iodo, fluoro, trifluoromethyl, nitro,
amino, (lower)alkylamino, di(lower)alkylamino, (lower)-
~lk~noyl, (lower)al~anoyloxy such as p-acetoxy or phenyl
and Y is amino or a group obta~ned by reacting the amino
group with acetaldehyde, formaldehyde or acetone, fluoro,
chloro, bromo, iodo, hydroxy, (lower)alkanoyloxy7 carboxy,
gu~nidino, 3-guanyl-1-ureido, 3-(2-furoy~)ureido, 3-~enzoyl-
ure~do, sulfo, sulfo~mlno, ureido, thioureido, (lower3-
~lkoxy, cyano, cyanam~no or indanyloxycarbonyl.
Other preferred acids, esters and salts of formuia
II ere those in which R i~
Ar'-7H-Co-
wherein Ar~ is phenyl, p-hydroxyph~nyl, 4-hydroxy-~,5-
d~chlorophenyl, 3-chloro-4-hydroxyphenyl, o-, m- or p-
~minomethylphenyl, 2-thienyl, 3-thienyl, l-cyclohexenyl ~.
or 1,4-cyclohexadienyl and Y i6 amino, carboxy or nydroxy.
Other preferred compounds of formula II are those
wherein R is an ~cyl group of the formula
~ 10~3CH-CO-
rl Cl
~O ~ C~-CO- ~
N~ Q ~ CH~Co_
~ N~2
~s~L CH-CO- ~CI H-CO-
NH2 ~CH-CO-
. . l~5~L CH-CO-
OH
CH-CO-
I~)H ~H-CO-
C~l-CO- ~-CoHoHO-
CH-CC~
CH~
(~OOH
CO- ~H-CO- , vr
COO~l
CO_
c~,O
~ b
Qther preferred compounds of formula II are those
whereln R is an acyl group of the for~ul~
OCH3
N--C-CH2CO- , ~ CO-
CH3
N _ N
\N-CH ~0- ~=`\
N- ~ 2 ~ ~ CH2-CO-
U
~0-
wherein U and V are alike or different and each ~3
hydrogen, chloro or fluoroj
2CO- ~:H2CO-
~:U2CO- , ~>--CH2CO-
OCH2CO- . ~SC~zC( - '
. .
~9
' ` ~H2NH2
~CH2CO- , Cl-C7 alkyl-CO-
<~ Cû- ~ CR;~Cû-
OC2~5
CO- ~CH2CO-
Cl-C7 altcoxy-CO-, O~CO- .
N~2
~2 )-NH-CH2Co ,
NH ~7CH2NHCO~
/N~
¦ ~ C -CH2CO- ,
o--I--c~ C~2co-
--30--
`~ `
~i 34
, COOH C~H~
~ ~~ , ~CO- ,
..,,j
~ ~ CO- ,~ CH-C~- or
, ~7H
CH2~2 ~ =C -NH-C= O
SCH2CO- C~H5
~1
~~ A mos~ preferred group of compounds are those
~-l ac~ds defined by formula II wherein R is ~-carboxy-
.~i phenylacetyl, cyanoacetyl, a-amino-a-~p-hydroxyphenyl~-
acetyl, a-amino--~3-chloro-4-hydroxyphenyl)acetyl,
~.~
a-amino-a-(3,5-dichloro-4-hydroxyphenyl)acetyl, c-
emino-a-(2-~hlenyl~acetyl, a-amin~-a-(3-thienyl)acetyl,
~-smino-a-(l-cyclohexenyl)acetyl, a-amino-a-(l,4-cyclo-
hex~ienyl)acetyl, c-hydroxyacetyl, a-hydroxy-a-
~2-thieny~)acetyl, a-hydroxy-a-(3-thienyl)acetyl,
a-hydroxy-a~ yclohexenyl~cetyl, ~-~yd~oxy-~-(i,4-
cyclohexadienyl)acetyl, ~-c~rboxy-c-~2-thi2nyl~2cetyl,
a-carbQxy--(3-thienyl)acetyl, c~rboY~y~ l-cyclo-
~exenyl)acetyl, ~-carbQxy-~-(1,4-cyclohexadienyl)-
8ce~ indanyloxycarbonyl-~-p'.lenylacetyl, l-(lH~-
~ trazoly~, 4 pyridylthi~cetyl, ~-thienylacety~
3 thienylacetyl, l-cyclohexenyl~cetyl, 1,4-cyclo-
hexadienylacetyl, o-aminomethylphenylacetyl~ loamir.o-
cyclohexylcarbonyl, 2,6-dimethoxybenzoyl, sydnone-
~cetyl or ~-azidophenylacetyl, or a pharn~ceutically
~cceptable salt thereof.
Another most preferred group of compounds are the
D-isomers of those scid~ defined by formula II wher~in R is
a-amlno-a-(p-hydroxyphenyl)acetyl~ a-amino-a-(3-chloro~4-
hydroxyphenyl)acetyl, ~-~mino-a-(3,5-dichloro-4~hv~roxyphenyl)-
~cetyl~ ~-amino-a-~2-thienyl)~c etyl, a-amino-a-(3-thienyl)-
~cetyl, ~-amino-~-(l-cyclohexenyl)acetyi, a-amino-~-
(~,4-cyclohexadienyl)~cetyl, ~-hydroxyacetyl, ~-hydroxy-
-(2-thienyl)acetyl, ~-hydroxy-a-(3~thienyl)acetyl,
~-hydroxy-a-(l-cyclohexenyl)acety~ or ~-hydroxy-~-
(1,4-cycloh~xadienyl)acetyl, or 2 pharmaceutlcally
ac~ep~able salt thereof~
A.mo~t preferrPd compound of form~la II is the ~cid
~n which R is phenoxyacetyl~ or a pharmaceutically
3~ceptable sal~ thereof~
Ancther most prefer.ed compound of .orm~lla II ~s the
~cid ~n which R is phenyl~cetyl, or ~ phsrmaceutically
~ccept~ble salt thereof. _
A $ 11 furth2~ m~t preferr~d c~m?ound ~ ~r~uia i L
i~ the scld ~n which R ~ a-aminophenylacetyl, o, a
: 1~13f~
`.
pharmaceutically acceptable salt thereof. The isomer of this
compound in which the~-carbon atom of the 7-acyl group is of
the D-series is of particular importance due to its combination
of good antibacterial activity and oral absorption.
A most preferred series of compounds of the present inven-
tion are the 0-2-isocephem compounds having the general formula
H H
R-NH ~
; 10 IIId ~ N ~ CH3
3! co 2H
;~ wherein R represents an acyl group, and easily cleavable esters
and pharmaceutically acceptable salts thereof.
Preferred acids, esters and salts of formula IIId are
those in which acyl group R is selected from the acyl groups
e
defined above under (i~ to (xvi). The acyl groups mentioned as
being preferred groups within categories (i) to (xvi) are also
- preferred in the compounds defined by general formula IIId.
More preferred acids, esters and salts of formula IIId
are those in which acyl group R is
Ar'-CH-CO-
in which Ar' is a radical of the formula
Rn ~ ' C3 ~
in which Rm, Rn and R are alike or different and each is hydro-
gen, hydroxy, (lower)alkyl, cyano, (lower)alkoxy, chloro,
bromo, iodo, fluoro, trifluoromethyl, nitro, amino, (lower)alky-
lamino, dl(lower)alkylamlno, (lower)alkanoyl, ~lower)alkanoyloxy,
- 33 -
e.g. acetoxy, or phenyl and Y is amino or a group obtained by
. reacting the amino group with acetaldehyde, formaldehyde or
. acetone; fluoro; chloro; bromo; iodo; hydroxy; (lower)alkanoy-
. ~
loxy; carboxy; guanidino; 3-guanyl-1-ureido; 3-(2-furoyl)-
.~ ureido; 3-benzoylureido; sulfo; sulfoamino; ureido; ~hioureido;
(lower)alkoxy; cyano, cyanamino; or indanyloxycarbonyl.
. Other preferred acids, esters and salts of formula IIId
are those in which R is
Ar'-CH-CO-
. 10 Y
.~ wherein Ar' is phenyl, p-hydroxyphenyl, 4-hydroxy-3,5-
.. dichlorophenyl, 3-chloro-4-hydroxyphenyl, o-, m- or p-
.. ~ aminomethylphenyl, 2-thienyl, 3-thienyl, l-cyclohexenyl or
.~ 1,4-cyclohexadienyl and Y is amino, carboxy or hydroxy.
~ .
. .,
,,'..
O~her preferred compounds of formula IITd are thc~e
wherein R 19 an 2cyl group of the forml~la
e~7H-CO- HO~CH-CO-
NH2 NH2
HO ~CH-CO-
\~J I ' HO -( ~ CH -CO-
NH2 C 1 N~2
L CH-CO- ~
NH2'
H-CO- . ~CH-Cû-
~CH-CO- , ~S~L CH-CO-
OX
<3~H-CC3
0~
~C -CO~ ~CH-~O-
H-CO-
COQH
C~OH-CO- ~H-CO- or
COOH
~3 ~H-CO-
1=
~ .
.
Other preferred compounds of formula IIId are
those wherein R ~s An acyl group of the formula
CSCH3
N_ C-CH2CO~ CO-
CH3
. N--N
~-C~ ~0~
N _ ~ ~;CH2-CO-
U
~ CO-
-~6--
whereln U and V are alike or different and each i~
hydrogen, chloro or fluoro;
~CH2CO~ H2CO-
~CH2CO~ CH2C-
.
OCH2CO- ~ ~SCH2CO-
CH2NH2
2C- , Cl-C7 alkyl-CO_
, ~3 ,
' ~CO^ ~2CO-
OC2H5
~I H2CO- ~CH2CO-
--37--
~13
Cl-C7 alknxy-CO-, O~CO-
NH2
- ~CH2~ CH2CO-, ~OCH2NHCO-
-CH2CO_
~N/
.. . . .~ , 0~ . , .
O--C--I--H ~--CH2C~)-
I2Co_
N
COOH C6H5
~~ , ~CO- ,
~ ' ~ CH-CO- or
NH
CH2NH2 O=C-NH-C--û
~SCH2CO~ 5
--38--
L~b
A most preferred group of compounds are those
acids defined by formulae IIId wherein R is ~-carboxy-
phenylacetyl, cyanoacetyl, a-amino-a-(p-hydroxyphenyl)-
acetyl, a-amino-a-(3-chloro-4-hydroxyphenyl)acetyl,
a-amino-~-(3,5-dichloro-4-hydroxyphenyl)acetyl, -
amino-~-(2-thienyl)acetyl, a-amino-a-(3-thienyl)acetyl,
a-amino-a-(l-cyclohexenyl)acetyl, ~-amino-a-(1,4-cyclo-
hexadienyl)acetyl, a-hydroxyacetyl, a-hydroxy-~-
(2-thienyl)acetyl, ~-hydroxy-a-(3-thienyl)acetyl,
a-hydroxy-~-(l-cyclohexenyl)acetyl, a-hydroxy-~-(1,4-
cyclohexadienyl)acetyl, a-carboxy-a-(2-thienyl)acetyl,
a-carboxy-a-(3-thienyl)acetyl, ~-carboxy-~-(l-cyclo-
hexenyl)acetyl, a-carboxy-a-(1,4-cyclohexadienyl)-
acetyl, a-indanyloxycarbonyl-~-phenylacetyl, l-(lH)-
tetrazolyl, 4-pyridylthioacetyl, 2-thienylacetyl,
3-thienylacetyl, l-cyclohexenylacetyl, 1,4-cyclo-
hexadienylacetyl, o-aminomethylphenylacetyl, l-amino-
cyclohexylcarbonyl, 2,6-dimethoxyben20yl, syndnone-
acetyl or ~-azidophenylacetyl, or a pharmaceut-cally
acceptable salt thereof. The most preferred easily
cleavable esters of this group are the pivaloyloxymethyl
methoxymethyl, indanyl, phthalidyl and acetoxymethyl esters
and pharmaceutically acceptable salts thereof.
- 39 -
Another most preferred group of compounds are the
D-~somer~ of those acids defined by formula IIId wherein
R is a-amino-~-(p-hydroxyphenyl)acetyl~ a-amino-a-(3-
chloro-4-hydroxyphenyl)acetyl, ~-amino-a-(3,5-dichloro-
4-hydroxyphenyl)acetyl, a-amino-a-(2-thienyl~acetyl,
a-amino-a-(3-thienyl)acetyl, a-amino-a-~l-cycloh~xenyl)-
acetyl, ~-amino-a-(I,4-cyclohexadienyl)acetyl, ~-hydroxy-
~cetyl, a-hydroxy-~-(2-thienyl)acetyl, a-hydroxy-a- -
(3-thienyl)acetyl~ ~-hydroxy-a-(l-cyclohexenyl)acetyl
or a-hydroxy-~-(1,4-cyclohexadienyl~acetyl, or a pharma-
ceutically acceptable salt thereof. The most preferred
e~s~ly cleavable esters of ~his group are the pivaloy-
loxymethyl, methoxymethyl, indanyl, phthalidyl and acetoxy-
methyl esters and pharmaceutically acceptable salts thereor.
. ' j .
A most preferred acid of formula IIId is that in
which ~ is phenoxyacetyl, or a pharmaceutically acceptable
~alt thereof.
A most preferred acid ~f formula IIId is that in
which R ic phenylacetyl, or a pharmacue~ically acceptable
~31t thereof.
A msst preer~ed acid of formuia ~IId is that in
whlch R is -aminophenylacetyl, or a pharmac~ut~c~ly
~c~pt~ble salt ~hereof,
--40--
~. 1~
A most preferred compound of formula IIId is
the pivaloyloxymethyl, acetoxymethyl, lndanyl, phthalidyl
or methoxymethyl ester of the acid in which R is a-amino-
i ~ phenylacetyl, or a pharmaceutically acceptable salt the~e-
- ~ of.
A still more preferred compound of fonmula IIId
,, .
~ is the D-isomer of an acid of formula IIId in which R is
; ~ a-aminophenylacetyl, or a pharmaceutically acceptable
salt thereof. This compound is found to be especially
valuable in view of its combination of good antibacterial
activity and oral absorption. The pivaloyloxymethyl,
acetoxymethyl, indanyl, phthalidyl and methoxymethyl ^
esters of the above acid as well as pharmaceutically
acceptable salts thereor are also preferred compounds :,,'
of the present invention.
~, The present invention further provides various
- novel intermediates useful in the synthesis of the
, ,, . ^~,~
pharmacologically active 0-2-isocephem antibacterial
agents described above.
Preferred embodiments of the present invention
are the novel intermediates having the formula
` H H
C2R"
:~ V
wherein W' is hydrogen, (lower)alkyl or aralkyl and R"
is hydrogen or an easily cleavable ester carboxyl-
protecting group, and salts thereof.
! Especially valuable are the compounds of formula
- 41 -
¦ wherein ~' is hydrogen, methyl, ben2yl or phenethyl.
The mo~t preferred intermediates of formula V
are those in whic~ ~' is methyl.
Other preferred intermediates are the compounds
having the formula
H H
O~W'
CO2R"
VII
,:
wherein W' is hydrogen, ~lower~alkyl, e.g. methyl, or
aralkyl, e.g. benzyl or phenethyl, and R" is hydrogen
or an easily cleavable ester carboxyl-protecting group,
and salts thereof. The most preferred intermediates of
.
formula VII are those in which W' is methyl.
...
The intermediates of formulae V to VII may be
,~.
in the form of the free carboxylic acid or a salt thereof
.,
:~ or in the form where the carboxyl group is protected
in a conventional manner such as preferably by ester-
ification. The protecting group is selected so that
it may be removed by methods which do not result in
any appreciable destruction of the remaining portion
of the molecule. Preferred carboxyl protecting groups
are the easily cleava~le esters as defined above including
in particular benzhydryl, p-nitrobenzyl, trichloroethyl,
silyl including especially trimethylsilyl, phenacyl, p-
methoxybenzyl, acetonyl, (lower)alkyl such as methyl,
t-butyl or ethyl, benzyl, triphenylmethyl, phthalidyl,
indanyl, methoxymethyl, acetoxymethyl and pivaloyloxy-
methyl. The most preferred esters of formulae V to VII
are the pivaloyloxymethyl, methoxymethyl, phthalidyl,
- 42 -
,. l~
, indanyl and acetoxymethyl esters, and salts thereof, The carboxyl
;} protecttng group may be spl~t off when des-ired by methods known
E~ se, e.g. by mild acid or base hydrolysis, catalytic hydro-
. ~
genatlon, irradiation ~ith ultraviolet light, or reduction with
' ~ I
chemical reducing agents. It will ~e appreciated that esterifica-
tion is only a preferred method for blocking the carboxyl group
, ;~ and that other carboxyl-protected forms of the above intermediatese.g. easily cleavable amides or anhydrides, are also intended to
r ~ be included within the scope of the invention.
- According to the present invention there is also pro-
vided a process for preparing 0-2-isocephem compounds of the
general formula H H
N~b
~ wherein R represents an acyl group and Q is hydrogen, (lower)-
J,f alkyl or aral~yl, and easily cleavable esters and pharmaceutically
-1~ 20 acceptable salts thereof, which process comprises ~-acylating a
,,
~ 7-amino 0-2-isocephem intermediate of the formula
-
H H
H2~ - _
::, ~
O ~ ~ Q
V~I CO2R"
wherein Q is as defined above and R" is hydrogen, or an easily
cleavable ester carboxyl-protecting group R', or a salt thereof,
with an acylating acid of the formu~a
R-COOH
- 43 -
.. ... . . . . . . . . .
~13~
. wherein R is as defined above, or with its functional equivalent
. as an acylating agent for a primary amine, to produce a 7-
~ acylamido 0-2-isocephem-4-carboxylic acid derivatlve of the
:. formula
; R-N ~
. ~b CO2R" Q
wherein Q, R and R" are as defined above, or a pharmaceutically
acceptable salt thereof and, if desired, performing one or
~ more of the additional steps of
.~ (1) removing by metho~s known per se the carboxyl-protect-
.~ ing group R' to produce the corresponding free acid compound of
. formula II;
. ~ (2) converting the free acid compound of formula II to a
. : physiologically hydrolysed ester thereof by methods known per
se; or
. _ .
t3) converting the free acid compound of formula II or a
-;
physiologically hydrolyzed ester thereof to a pharmaceutically
acceptable salt thereof by methods known per se.
The 7-acylamido 0-2-isocephem compounds of formula II are
prPpared by N-acylation according to known methods of the 7-
amino group of intermediate VII with an acylating acid of the
formula
R-COOH
wherein R is an acyl group, or with its functional equivalent
as an acylating agent for a primary amino group.
Tho acylating agents for preparing the
I
~44-
~346~
products of formula II are known, readily preparable
by known methods or described herein.
Intermediate VII may be acylated either
in the form of the free carboxylic acid (or
salt thereof) or as an easily cleavable ester (or acid
addition salt thereof). The procedures for preparing
esters of carboxylic acids are disclosed in the litera-
ture and are well-known to those skilled in the art of
penicillin and cephalosporin chemistry. Methods for
preparing certain of the more preferred easily cleavable
esters, i.e. the pivaloyloxymethyl, acetoxymethyl,
methoxymethyl, acetonyl and phenacyl esters, are disclosed
in U.S. Patent 3,284,451 and in U.K. Patent 1,229,453.
The free acid form of intermediate VII may also be converted
to a silyl ester, e.g. trimethylsilyl ester, as by the
methods described in the literature, e.g. U.S. Patent
3,249,622. The silyl ester carboxyl-protecting group
may be easily removed following the acylation reaction
by hydrolysis or alcoholysis.
Prior to the acylation reaction, any reactive
substituents on the acylating acid or derivative
thereof, e.g. hydroxy, carboxyl or mercapto, may be
protected by use of suitable protecting or blocking
groups which are well-known to those skilled in the
art of ~-lactam chemistry, e.g. as by acylation or
silylation. When the acylating agent contains an
amino functional group in the acyl moiety, the amino
- 45 -
$~
group is protected by a conventional amino-blocking
group which may be readily reved at the conclusion
of the reaction. Examples of suitable amino-protecting
or blocking groups include t-butoxycarbonyl, carbo-
benzyloxy, 2-hydroxy-1-naphthcarbonyl, trichloroethoxy-
carbonyl, 2-ethoxycarbonyl-1-methylvinyl and 2-methoxy-
carbonyl-l-methylvinyl. A particularly valuable
blocking group is a proton, as in the acylating agent
of the formula
CH-C-Cl
NH HCl
Preferred amino-protecting groups are t-butoxycarbonyl,
carbobenzyloxy, the proton and a ~-diketone or
~-ketoester as in U.K. Patent 1,123,333 or U.S. Patents
3,325,479 and 3,316,247, e.g. methyl acetoacetate,
or a B-ketoamide as in Japan 71/24714. When the
t-butoxycarbonyl, carbobenzyloxy, ~-ketoester, ~-dike-
tone or ~-ketoamide protecting groups are employed,
it is preferred to convert the acylating acid
containing the blocked amino group to a mixed anhydride,
e.g. with ethyl or isobutyl chloroformate, before
reaction with compound VII or an ester or salt
thereof. After the acylation coupling reaction,
-- 46 --
- the amino-protecting group and any other protecting
group used may be removed by methods known per se to
form the desired product of formula II. Thus, for
example, with respect to amino-protecting groups, the
t-butoxycarbonyl group may be removed by use of
formic acid, the carbobenzyloxy group by catalytic
hydrogenation, the 2-hydroxy-1-naphthcarbonyl group
by acid hydrolysis, the trichloroethoxycarbonyl group
by treatment with zinc dust in glacial acetic acid,
the proton by neutralization, etc.
Acylation of a free amino group of a cephalosporin
or penicillin nucleus is a well-known reaction, and any
of the functional equivalents of the carboxylic acid
RCOOH commonly used in penicillin or cephalosporin
chemistry as acylating agents for primary amino groups
may be employed in acylating intermPdiate VI.
Examples of suitable acylating derivatives of the free
acid include the corresponding acid anhydrides, mixed
anhydrides, e.g. alkoxyformic anhydrides, acid halides,
acid azides, active esters and active thioesters. The
free acid may be coupled with compound VI
after first reacting said free acid with N,N'-dimethyl-
chloroformininium chloride ~cf. Great Britain 1,008,170
- 47 -
t~
and Novak and Weichet, Experientia XXI, 6,
360(1965)~ or by the use of enzymes or of an
N,N'-carbonyldiimidazole or an N,N'^carbonyl-
dltri~zole [cf. South Afr~can Specification
63/2684] or a c~rbodiimide reagent ~especially N,N'-
dicyclo~er~ylcarbodiimide, N,~'-d~isopropylcarbodiimide
or N-cyclohexyl-N'-(2-morpholinoethyl)car~odiimide:
~`_A cf. Sheehan and Hess, ~.A C.S., 77, 1967 (1955)3, or
of slkylylamine reagent Ecf. R. Bu~jle and H G.
Viehe, An~ew. Chem. Internat~onal Edition, 3, 582,
(1964)3 or of an isoxasolium ~alt reagent [cf. R. B.
Woodward, R. A. Olofson and H. Mayer, J. Amer. Chem.
. ;.,
Soc., 83, 1010 ~1961)~, or of a keten~mine reagent
[cf. C. L. Stevens and M.~E. Munk, J. Amer Chem. Soc.,
-~
, .
8~, 40~5 ~195~)3 or of hexachlorocyclotriphospha-
eA ~riszine or hex~bromocyclotriphosphatri~zine (U.S.
-: 3,651,0S0) or of diphenylphosphoryl azide EDPPA;
J. Am~r. Chem. Soc., 94, 6203-6205 (1972)3 or of
_ _ _ _ _
diethylphosphoryl cyan~de [DEPC s Tetsahedr~n Letters
No. 1~, pp. 1~95-1~98 (1973)3 or of diphenyl phosphite
lTe~rahedron ~etters No. 4q, pp. 5047-5050 (1972)3.
Another equ~valent of ~he acid chloride is a corres-
pondlng azol~de, i.e., an amide of the corresponding
ac~d whose am~de nltrogen is a ~ember of a quas~-
~ro=~tic five mem~ered rlr.g contaln~ng ~t lesst ~wo
:~
. nitrogen ato~s, i.e., imitazole, pyrazole, the
,. ,
:1 tr~szoles, benzimidzzo~e, benzotriazole ~nd ~heir
: ~ su~sti~uted derivative~. As aAn exam~le of the
: .~ general method for the preparation of an azol~de,
. .
N,N'-carbonyld~mldazole is reacted w~th a carbcxyLic
.,
ac~d in equimolar proportions at room temperature in
tetrahydrofusan, chlorofor~-, dimethylform~Am~de or a
similar inert solvent to form the carboxylic acid
~mldazo1ide in practically ~uant~ta~ive yield wi~h
liberat~on of carbon dioxide and one mole of imidazole.
Dicar~oxylic acids yield dimJ dazolide. The by-product,
~m~da~ole, precipitates and may be separated and the
,~
~ldazolid~ ~soL2ted, but this ~s not essent~al. A
~h preferred acylating agent for prepa_ing 7-acylamido
~q; compounds containing ~n a-amino substituent, e.g.
~r a-aminophenyl, a-~mino~a-thienyl, etc. is the ~-
.
car~oxy ~nhy~ride ~Leucn~s anhydride). In th~s
struct~;re the group which sctivates the carbox~l
group slso ser es to pr~tec~ the amino group.
Another preferred acylating agent for int:rodu ing
a ~ide ch~in containlng an a-~mino functional group
ls the acid chlor~dP hydrochloride, of ~ne form~la
Ar-CH-COCl
?~H2 ~C~
_ ,~ 9 _
wh~ch also serves a dual funceion of carboxyl acti-
va~ion and amino proeection. Mentlon was made above
of ~he ~se of enzymes to couple the free acid wieh
compc~nd v~ ncluded i~ the sc~pe of
such processes ~re the use of an ester, e.g. ehe
methyl ester, of that free acid with enzymes provided
by various microorganisms, e.g. those described by
,~,
T. Ta~xhashi et 81., J.A.C.S., 94(11~, 4035-4037 (1972)
.~ and by T. Nara ee al., J. Antibiotics (Japan) 24~5),
~i,C
321-323 (1971) and in U.S. 3,682,777. A particularly
preferred ~oupling agent ~o~r coupling the acylating
. acid with c~mpound VII (or a salt or ester
thereof) ls ~-ethoxycarbonyl-2-ethoxy-1,2-dihydro-
~ . ...
~ ~u~r.oline (EEDQ) 8S described in J.A.C.S., 90, 823-824
, .
and 1652-1653 ~1968) and U.S. Patent 3,45~,929.
The partic~lar process conditions, e.g. tem~er-
s~ure, ~ol~ent, re~ction time, etc. sele~ted fos ehe
coupling reaction are determined by the nat~re of
the seactants and scyl2tion method used and are ~nown
to ~hose s~illed ~ the art.
She scyl2ting agents which may be used to ~o~m
the ~oscyl sc~ve c~mpounds of fsrmula II
~e kn~wn in the l~terature along with methods or
I their ~ynthes~s. ~n those cases where the acylating
-- ~o --
1~
ù agent coneains one or more 2sy~me~ric carbon at~s ant
ehus ex$sts in optically zcti~e for~s, the c~pounds
obtained using suc~ an acylating agent ase ordins:ily
i;~
~btained ~n race~c form. When the s2parate.0pt$csl
i80~r8 are desired, the acylating agent can be
res~lved in a conventlonal manner such as by reacting
. 'he free acid with cinchonine, strychnine, bruci~e or
th~ like, fr~ctionaLly crystallizing eo sepas~te the
. ~isstereoisomeric salts and separately acidi~ying the
:'~
solid p~.ase and the liq~id pha~e to lib~rate the
opt$cal iso~ers.
.. The compo~nd~ of the present ~nve~tion may be
:~ ~601ated in any ~f the ways customa~ily e~ployed for
.. ~ the ~solation of corresponding cephalosporin compounds.
~.~, Fo~mfition of the desired phar~aceueically acceptable
. ~
-~ carboxylic acld or acid addition sa~t is car~ied out
.;
by kn~wn methods, e.g. react~on of the acid (or ester
¦ ~n the case of acid addition salts) with ~n appropriate
basD o~ acid.
At the conclusion of the acylation reaceion, the
psotu~t obtaine~ may be con~ert~ (be~ore or after
remc~al of any prot~cting groups~ by ~ethods kno~n
per se ~o another desired produc ' of formula II .
Thus, the compaund o~ 'ormula II
i
~ -5~-
in t~e form o~ the free acid or a salt thereof may
be converted by kno~n methbds to the corresponding
physiologically hydrolyzed este~ or phaLmaceutically
acceptable salt t~ereof. Similarly, the product
of formula II in the form of an easily
, cleavable ester or salt thereof may be converted to
;-, the free acid product or pharmaceutically acceptable
salt thereof by removal of the esterifying group, e.g.
by aqueous or enzymatic hydrolysis (as with human or
animal serum) or acidic or alkaline hydrolysis or by
catalytic hydrogenation or by treatment with sodium
thiophenoxide as taught in U.S. Patent 3,284,451.
The easily cleavable esters of the compounds
of formula II are useful as intermediates in the
production of the free acid product. The pivaloyloxymethyl,
acetoxymethyl, phthalidyl, indanyl and methoxymethyl esters
are also useful as active antibacterial agents since on
oral administration they are rapidly hydrolyzed to the
active metabolite. These esters are of particular interest
2~ because they provide on oral administration different rates
- and amounts of absorption and give differing concentrations
of the active antibacterial agent in blood and tissues.
. .
. .
,'
.
1~34~
' ~:
, ~
~, ln still another aspect af e~e present ~nvent~on,
.,
~:Z there ~s p.ovided 8 process for the preparation of sn
0-2-isocepbem-3-carboxymethylene der~vat~ve of the
:~ . ~ormula
. H H
R-
~i~ ,~L ~ CH2CO~ IZ
2~
wberein R represent- an acyl group and Z Ls hytro~en or
: ~ the res~ue of an ester group and easily cleavable esters
~c;
,, .~
. ............... f and ~h~rm~ceutically accPptable sal s thereof; which
, l process comprises
:~ (1) reacting an 0-2-~socephem compound o. the
, formula
R~cp~3
, ~ ~)2R
.,
IIIb
: wherein R represents an acyl grolp ~nd R' is sn easily
- clea~able ester car~oxyl-protecting gro.~p with car~on
. .
dioxide ~n the presence of a base in an ~nert organic
~.
so~ven 8t a tem?erature in the range of about 0~. to
-~3-
3L~
-8nDc. to produce ~pon acid~ fication the compou;~d of
the f onnula
H H
R~
~ l
ag~ ~f~2CO2R
XXII Ct}2R '
wherein R and R' are as defined ab~re, or a pharTna-
eeuticalty scceptable salt thereo~ and ~ptionally
performing one o~ more of ehe add~Iona~ steps of
~ a) remoY~ng by methods know;~ per se
the pro~ecting ~roup R ' to produce the
~orresponding 4-carboxyl~c acid compound
~f formula XXIT;
.
~ b) conv~rting the 4-carbaxylic acit
compound of for~nul~ XXII to a physlologically
h7drolyzed ester therPof by methods known per
se; or
~ c) con~erting ~y methods knowrL per se
the 4-c~rb~:ylic ac~ d cor.tpound of ,or~ula
XXII or a phys~ olog~cally h~droiyzed ester
thereof to a ph~rmarelltirGlly slcee~t2~1e
sait there~f; and, when ~t is ~eslred to-produce
a c~mpot_nd of ~crmula IV where Z is the residue Oc
an ester gr~up,
(2~ esterifying tne f~ee carbo~yl ~roup 2~ the 3-posi-
t~cn of compound X~II by ~etr.ods known ~ se to p~od~.e
a compound of the for~nula
H H
R~
~0
2COOZ
C2na
wherP~n 2 is the res~due of an ester group snd R and R '
sre as dPfined above, or a pharmaceutica lly 2ccept~ble
salt thereof and, if desired, performing one or more Qf
t~e sdd~ tional steps of
(d) select~vely removing by methods known
per se the protecting group R~ to produce the
desired 4-carboxylic acld compound of formula
~V wherein Z is the residue of an ester group;
(e) converting the 4-carboxylic acld
c~mpound of step ~d) to a physiologically
hydrolyzed ester thereof by methods ~nown
per se; or
~ . ~f) converting by mPthods knoun per
8~ the 4-carboxylic acid comp~nd or step
(d3 or a physio~ogically hydrolyzed ester
thereo~ to a pharmaceut~caily accepta~le
s~l~ ther20f.
-55-
Acyl group ~ in starting material I Ib may be any
organic acyl radical but is preferably selected from
those acyl groups described above as preferred in connec-
tion with the compounds of general formula I. Carboxyl-
protecting group R' may be any easily cleavable ester
group conveniently used to block a free carboxylic acid
functional group. The term "easily cleavable" has the
same meaning as described previously, i.e. removable by
methods which do not result in any appreciable destruction
of the remaining portion of the molecule. Preferred
protecting groups are benzhydryl, benzyl, p-nitrobenzyl,
trichloroethyl, silyl including especially trimethylsilyl,
phenacyl, p-methoxybenzyl, acetonyl, (lower)alkyl including
particularly met~yl, ethyl and t-butyl, triphenylmethyl,
methoxymethyl, acetoxymethyl, phthalidyl, indanyl and
pi~aloyloxymethyl.
The carboxylation reaction is carried out by reacting
the carboxyl-protected compound Ib with gaseous carbon
dioxide in the presence of a base. Suitable bases for
this step include sodium hydride, n-butyl lithium, t-butyl
lithium, lithium dicyclohexylamine, lithium 2,2,5,6-tetra-
methylpiperidine and lithium diisopropylamine. The pre-
ferred bases are n-butyl lithium and t-butyl lithium.
The ester IIIB LS dissolved in a dry inert organic solvent,
e.g. tetrahydrofuran, and dry gaseous CO2 introduced into
~ 3~ ~
the ~.ixture of base and IIIb soluti~n. The reaction
~ixtu~e is cooled before ~nt.oduction of the C02 to
a tem?eratuxe ~n the range of ~C. to -80C. and then
2110wed to war~ to room temperatu.e with cont~nued
addition of carbon-dioxide. Upon acidification~ e.8
with si m~neral ac~ such as aqueous HiCl, co~ound XXII
m~y be recovered.
Upon cleavage of carboxyl-protec~ing group R' to
form a free 4-carbo~yl group, e.g. by hydrolysis,
chemlcal reduction or catalytic hydrogenatio~, t~e
~-carboxym~thyl acids prepared by .he carbcxylation
s~ep or physiologically hydro~yzed esters or pharma-
~eut~cally acceptable salts of 6aid acids or esters may
be used a active antibacterial ~gents.
Compound XXI~ m~y also be esterified by kno~ method~
to for~ the desired c~rboxyl-protected compound of for~ul2
IYa where Z ~s the residue of an es~er group, most
p~efera~ly Cl-C~ alkyl, e.g. methyl, ethyl~ n-propyl,
i80p~0pyl, n-butyl, isob~tyl, se~-butyl, t-~utyl, n-per,.-y'
~-heptyl, etc. The ester group Z should be one which ~s
res~stant .o condi~io~s required for removal c~ blockin~
grcup R', e~g, resistant tc hyd-cgenclysis. T~.e ~ost
preferred es-ter, the mPthyl este~, ~ay be prepared fo~
i~xample by s~action of compound XXII wi~h diazomethane,
The preferred lGwer alkyl esters m~v also be for~ed by
use or the mixed ~nhyd~ide reac~ion or by the use OI
l$~
dimethylformamide acetals as descr~b~d in Hel~. Chim.
Acta., 48, 1746 (1965~. Upon select~ve clea~ge of
~locking group R' by kn~wn methods, e.~. acid labile
~locking ~roups such as t-butyl, p-m2thoxyben~yl or
te~:rak.ydrop~any~ may be selecti~ ely removed ~y mild
acid treatment and groups s~ch as benzyl or p-nitrcbenzyl
may be sel~ct~vely removed by ~drogenolysis, t~e inter-
mcdiatos of form~la I~a ~here Rl is not physiologically
hydrolyzed may be converted to 4-carboxylic acid active
snt~bacteria7 agents. The free acid products may option-
ally be converted according to kn~wn me~nods to physiolog-
~csl~y hydrolyzed esters or pharmaceutically scceptable
salts thereof,
T~e comp~unds ~nd pharmaceu~ically ac~eptable sal~s
of form~as XXII wherein R' is a physiologica}ly hydroiyze~
es~er group cr the de-blocked compounds of formula XXII
or physiologically hydrolyzed esters or pharmaceutic~lly
ac~epta~le salts of said ac~ ds cr es~ers are as ~entioned
abo~e actlYe antlbacter~al age~ts. These compounds and
salt~ have approxim~tPly the same d~gre~ of sctivity as
t~e ac~ds, ph~siolog~cally hydrolyzed es~ers and pharma-
ceutical ly acceptabl~ sa~ ts of formul~ IY, but are more
d~ fflcult to ~sc~ate from th_ reaction mixture because of
tho presenc~ of the fr~e car~ox~rl group on the 3-position.
For this roason, Lh~ ~re~er~ed c~p~unds and s21ts OL
f~rmula IY are those h~v~ng ~he es~r~ fied ~a-bcxy~ ethylene
3 s~s~itllent, most pr ferabl~ ~hoj~ haYlng a Ci-C6 a'k~
rad~czl or thq ~ substituent.
1Si1~346~;
The pharmaceutically ac~ive compo~nds o~ the
present invention sre potent ant~bacterial agents
~seful in the treatmen~ of infectio~s diseases in
poultry and anima~s, ~ncluding man, caused by many
~ram-pos~t~ve and Gram-negative bacteria. The active,
compound~ are also of value as nutritional supplements
in ~n~al feeds and as agents ~or the ereatment of
mastit~s in cattle.
The novel medicaments pro~ide~ by the ?resent
~n~ention may be formulated as phsrm~ceutical com?osi-
tions cprising, in 2dd~tion to the active ingredien.,
a pharmaceuticslly acceptable carrier or diluent. The
com~unds may be admini~tered both orally and parenterally.
The phsrm2ceutical preparations may be in solid form such
8S capsules, tabLets o~ dragees, or in liquid form such
a~ solutions, suspensions or emulsions. In the treatment
of bacteri~l infections in man, the ac~ive compounds of
th~s ~n~ention m~y be aGm~nis.ered parenterally or ora~ly
in an amol~nt of fro~ about 5 to 2~0 mg/Kg.Jday and
preferably a~out S to 20 mg.Jxg.~day in divided dosa~e,
e.g. thre~ or four times a day. T~ey are admlnistered
in dosa~e ~ni~s contain~r.g, fo, ex.ample, 125, 250 or
~00 mg. Gf act~ve ingredient w.th suitable 2hys~ologi-
c~lly acceptable carriers or excipLencs.
6~;
Another preferred embodiment of the present
invention is the process of preparing a 7-amino
0-2-isocephem intermediate of the formula
N ~ Q
C2R"
VII
wherein Q is hydrogen, (lower)alkyl or aralkyl
and R" is hydrogen or an easily cleavable ester
carboxyl-protecting group, or a salt thereof; which
process comprises selectively reducing a 7-azido
intermediate of the formula
N H H
3 ~
N ~ W
O
-
wherein W is as defined above, R' is an easily cleavable
ester carboxyl-protecting group and, if desired, removing
protecting group R' by methods known E~ se to produce the
corresponding freeacid intermediate of formula VII and, if
desired, converting the free acid form of intermediate
VII to a salt thereof by methods known per se.
~ - 60
1~1346~
Another preferred embodiment o the present invention
is the process of preparing a 7-azido 0-2-isocephem ir~termediate
of the formula
~'
,.
V N
., C2Rn
s~,
,'t~ wherein W is hydrogen, (lower~alkyl or aralkyl and R" is hydro-
gen or an easily cleavable ester carboxyl-protecting group, or
,
a salt thereof; which process comprises cyclizing by treatment
with base an enol intermediate of the formula
.;~
~,,
H H CH2OSO2-(lower)alkyl
C--I /
o = C - N \ / OT
, C2R '
~-i 20 wherein T is hydrogen or ethyl, W' is hydrogen, (lower)alkyl or
aralkyl and R' is an easily cleavable ester carboxyl-protecting
group and, if desired, removing protecting group R' by method~
known ~ se to produce the corresponding free acid intermediate
of formula V and, if desired, converting the free acid to a salt
thereof by methods known ~ se.
Preferred reducing agents for this step include chemical
reducing agents selected from zinc and ammonium choride in an
inert organic solvent, e.g. methanol, and hydrogen sulfide and
triethylamine in an inert organic solvent, e.g. methylene
chloride. Catalytic hydrogenation may also be employed with
such selective hydrogenation catalysts as noble metals (most
preferably palladium or platinum), noble metal oxides (most
_61_
preferably palladium oxide or platinum oxide), or Raney nickel,
said catalysts being optionally supported on a conventional
carrier such as carbon, diatomaceous earth, etc. Preferred
solvents for catalytic hydrogenation are non-reducible inert
solvents such as methanol, ethanol and ethyl acetate. Hydro-
,~
genation is preferably conducted at room temperature and atatmospheric or slightly elevated pressure. As in the case
of the 7-azido 0-2-isocephem intermed~ate discussed above,
compound VIIa may, if desired, be converted by methods known
~ 10 per se to the corresponding free carboxylic acid form or
- to a salt of either the esterified or free acid form. As an
ie
alternative to the stepwise reduction of the azido group and
, removal of the ester carboxyl-protecting group, it is also
possible by choice of proper reduction conditions and protect-
ing groups to simultaneously reduce the azido group and ester
protecting group. Thus if a mild hydrogenation catalyst
~"~
is used such as 10% Pd-on charcoal or a mild chemical reducing
agent such as H2S and triethylamine, the azido group is
,~:
reduced to an amine but a benzyl protecting group is untouched.
If a more active catalyst, however, such as 30% Pd-on-
diatomaceous earth is employed, both azido and benzyl groups
are reduced.
Compound VII or an easily cleavable ester or salt
thereof is of use primarily as an intermediate in preparing
the active N-acyl derivatives of formula II. Compound
VII upon conversion to the free carboxylic acid (or a
physiologically hydrolyzed ester or pharmaceutically accep-
table salt of said acid or ester) also possesses antibacterial
activity per se against Gram-positive and Gram-negative
bacteria.
i
Enol intermediates IX which, depending on the
definition of T and W', are prepared by various
methods described below, are cyclized to the azido 0-2-
isocephem intermediate V by treatment with a base.
Examples of suitable bases for this step incllde an alkali
metal hydride, most preferably NaH, in a suitable organic
solvent, e.g. dimethylsulfoxide or dimethylformamide,
~:~ triethylamine in an inert organic solvent such as methylene
chloride, chloroform or (lower)alkanols, e.g. methanol or
ethanol and sodium or potassium acetate in a suitable
solvent such as dimethylformamide. Generally it is
preferred to employ the azido 0-2-isocephem in its
carboxyl-protected form in preparing the active 0-2-
isocephem antibacterial agents of formula I. If
desired, however, the ester group of intermediate
V may be removed by methods known per se to produce
the free acid form of compound V. The ester or free
-~ acid foxms of the azido-isocephem intermediate may
also be optionally converted by known methods to
~,4 20 salts thereof.
. ~
._
,_
,
-63-
A further preferred embodiment of the present
invention is a process for the preparation of an
enol intermediate of the formula
H H
N - _ ,~, CH20S02CH3
3 - C C " ~ H
I l C OH
o--c N \ C D
C02R
IXa
wherein Rl is an easily cleavable ester carboxyl-
protecting group; which process comprises subjecting
to acid hydrolysis a methanesulfonyl derivative of
the formula
H H
N _ _ / CH20SO2CH3
3 - C C
O - C N \ C N
C2R '
XVII
wherein R' is as defined above.
A further preferred embodiment of the present
invention is a process for the preparation of an enol
intermediate of the formula
H H
3~--C ~ / CH20S02CH3
l l OH
O ---C N \ F C~ W
X C~2R'
- 64 -
wherein W is methyl, benzyl or phenethyl and R' is an
easily cleavable ester carboxyl-protecting group; which
process comprises subjecting to acid hydrolysis a
methanesulfonyl derivative of the formula
H H
N _ _ _"'CH2S2CH3
3 ~ ~ ~
O = I N H \ ~
\ C ~ C~W
C2R'
XXVII
wherein R' and W are as defined above
wherein R' is an easily cleavable ester carboxyl-
protecting group and W is as defined above, or a salt
thereof and, if desired, removing protecting group R'
by methods known ~ se to produce the corresponding
free acid intermediate of formula VIII and, if desired,
converting the free acid to a salt thereof by methods
known per se.
A variation of the above-described process for pre-
paring the 0-2-isocephem antibacterial agents of formula II,
when W is hydxogen, and easily cleavable esters and pharma-
ceutically acceptable salts thereof involves reacting the
alcohol of formula XIII with a methanesulfonating agent in
the presence of an acid acceptor to produce a methanesulfonyl
derivative of the formula
H H CH2OSO2CH3
N3 C C / H OCH2CH3
O = C- N H C
C / 2 3
I
C2R'
XVIII
- 65 -
1~3g~
wherein R~ is an easily cleavable ester carboxyl-
protecting group. Compound XVIII is then reacted with
acetic anhydride in the presence of zinc chloride,
trifluoroacetic anhydride, titanium tetrachloride,
boron trifluoride or stannous chloride to produce a
compound of the formula
N3 - ~ / CH2OS02CH3
I ~ OCH2 CH 3
O C N C
~C~
12R'
XIX
wherein R' is as defined above. Compound XIX is then
subjected to base hydrolysis to form an enolate of
the formula
H H
N3 - - / CH20SO2CH3
--c f
O=C N\ DCHO
CO R'
XX 2
wherein R' is as defined above. ~nolate XX is cyclized
with base to the 7-azido 0-2-isocephem intermediate
of formula Va which is subsequently reduced, N-acylated
and optionally de-blocked according to the process described
above to produce the desired compound of formula II, when
W is hydrogen, or an easily cleavable ester or pharma-
ceutically acceptable salt thereof.
- 66 -
~3~1346~
A still further alternative process for preparing
compounds of formula Il, when W is hydrogen, involves
reacting the compound of the formula
H H
_ CH OH
3 ~ C - C /
I l IH OCH2CH3
o c N~CIDC~
C02R
XV
wherein R' is an easily cleavable ester carboxyl-
protecting group with a methanesulfonating agent
in the presence of an acid acceptor to produce a
methanesulfonyl derivative of the formula
N ~ - / CH2OSO2CH3
3~ C - C H
I ~OCH2CH3
O - C _ N \ C
C2R'
XIX
wherein R' is as defined above. Compound XIX is
then treated with base to produce an enolate of formula
XX and then cyclized by treatment with base to the 7-
azido 0-2-isocephem intermediate Va which is reacted as
described above to produce the desired compound of
formula II, when W is hydrogen, or an easily cleavable
ester or pharmaceutically acceptable salt thereof.
- 67 -
According to another aspect of the present invention,
there is provided a process for preparing a 7-amino 0-2-
isocephem compound of the formula
.
H H
. ~ O
'~ l l I
~ N ~
VIIa C2R'
. wherein R' is hydrogen or an easily cleavable ester
carboxyl-protecting group, or a salt thereofi
which process comprises the consecutive steps of
.
....
~.i
(1) reacting an ester of the formula
.
~ ........................ (CH3CEI20) 2CH-fH-C02R'
~! ~'' NH 2
~ XI
:
wherein R' is an easily cleavable ester carboxyl-
protecting group with cinnamaldehyde in an inert
,~ ....
organic solvent in the presence of a drying agent or
with azeotropic removal of water to produce an imine
of the formula
H 1I C6H5
C--C-- H H
. 1-- OCH 2C~ 3
\ C / 2 3
XII ~02R'
wherein R' is as defir.ed above,
~3~
(2) reacting said imine of formula XII with an
azidoacetyl halide on an azidoacetic mixed anhydride in
the presence of an organic base to produce a cis ~-
lactum compound of the formula
HC - C6H5
H ~ / C- H
N3 - Cl _ CHl / OCH2CH3
O - C N H C
\ f / OCH2CH3
C2R
IV
wherein R' is as defined above;
(3) subjecting said ~-lactum compound of
formula IV to ozonolysis to produce an aldehyde
of the formula
H _ CHO
N C f ¦ CH2cH3
O C - N H C
\ I / OCH2CH3
C2R'
XVIII
wherein R' is as defined above;
- 69 -
f~
(4) selectively reducing said aldehyde of
formula XVIII to the corresponding alcohol of the
formula
H H
- _ CH20H
3 ~ C ~ / ¦ / CH2cH3
O - C- - N H C
\ C / OCH2CH3
C2R '
XIII
wherein R' is as defined above;
(5) reacting the alcohol of formula XIII
with an acid anhydride in the presence of a Lewis
acid to produce a compound of the formula
H H
- ~ CH OCO-An
3~_ _ _ / 2
O - C N C ~ OCH2CH3
C2R'
XIV
wherein R' is as define~ above and An represents
the residue of the acid anhydride;
- 70 -
(6) subjecting the compound of formula XIV
to acid hydrolysis to produce a compound of the
formula
3 \ _ / 2 H
O --- C--1 1 ~ 0cH2cH3
\IC~
C2R '
XV
wherein R' is as defined above;
~ 7) reacting the compound of formula XV
with an amine to produce an enamine compound
of the formula
H H
~ ~ CH OH
~ C C/ 7 N-X~
O -_ C - N ~ C
C2R'
XVI
wherein R' is as defined above and X" is the residue
of the amine;
~ 8) reacting the enamine of formula XVI with
a (lower)alkylsulfonating agent in the presence of an
acid acceptor to produce a derivative of the
formula
H H CH2OSO2-(lower)alkyl
N3 _ _ /
C C t N-X"
Q C N C ~
\C~
12R'
XVII
wherein R' and X" are as defined above,
(9) subjecting said derivative of formula
XVII to acid hydrolysis to produce an enol inter-
mediate of the formula
H H
_ _ / CH2OSO2-(lower)alkyl
lC I IH OE~
O - C N C /
\IC~
C2R '
IX
wherein R' is as defined above;
~ 10) cyclizing said enol intermediate by treat-
ment with base to produce an azido 0-2-isocephem
intermediate of the formula
~ - 72 -
H H
N3 ~ ~
C C O
O C N ~
C2R
Va
wherein R' is as defined above;
(11) selectively reducing said azido inter-
mediate of formula Va to produce the compound of the
formula VII.
According to still another aspect of the present
invention, there is provided a process for preparing a
7-amino 0-2-isocephem compound of the formula
~2 ~ ~
, I I .
O , N ~
C2R
V_
wherein W' is methyl, benzyl or phenethyl and R" is
hydrogen or an easily cleavable ester carboxyl-
protecting group, or a salt thereof; which process
comprises ~he consecutive steps of
(1) reacting a ketal amine of the formula
W -/C - CH-COOR'
0~0 NH 2
X_
wherein R' represents an easily cleavable ester
carboxyl-protecting group and W is as defined above
~ - 73 ~
with cinnamaldehyde in an inert organic
solvent in the presence of a drying agent or with
azeotropic removal of water to produce an imine of the
formula
H H-C ~ 6H5
C -CH
N H \ C
\ I/ W
I
C2R '
XXIII
wherein R' and W are as defined above;
(2) reacting said imine with an azidoacetyl halide
or an azidoacetic mixed anhydride in the presence of a base
to produce a cis-~-lactam compound of the formula
H-C ~ 6 5
H H 11 H
= ~
3 ¦ ¦ 0\ ~0
O C N H C
\1/ \W
I
CO2
XXIV
wherein R' and W are as defined abo~e;
(3) subjecting said ~-lactam compound of formula
XXIV to ozonolysis to produce an aldehyde of the formula
H / CHO
N3 C - ~
\ /
O - C - N H C
\C/ \W
- - C02R'
1~
74
wherein R' and W are as defined above;
(41 selectively reducing the aldehyde of formula
XXV to the corresponding alcohol of the formula
H H
~ CH O
N3IC C A
~ ~o
O= C N\ I ~ C~
C W .
XXVI C02R'
wherein R' and W are as defined above;
(5) reacting said alcohol with a (lower)alkylsulfon-
ating agent in the presence of an acid acceptor to produce
a derivative of the formula
H H
N3 1 - ~ CH20S02-(lower)alkyl
O ~O
\ 7 ~
C W
XXVII C2R'
wherein R' and W are as defined above;
(6) subjecting said derivative of formula XXVII
to acid hydrolysis to form an enol of the formula
3________ _ / CH20S02-(lower)alkyl
1' 1 1~
X --C- N\CI~c\w
C2R'
- 75 -
wherein R' and W are as defined above;
(7) cyclizing the enol of formula X by treat-
ment with base to produce an azido 0-2-isocephem inter-
mediate of the formula
r
N
C2R '
V
wherein R' and W are as defined above; and
(8) selectively reducing the azido 0-2-iso-
cephem intermediate of formula VIa to produce a 7-amino
0-2-isocephem intermediate of the formula
H2N H H
~0
I
~ . N
O
C2R '
VIIIa
wherein R' and W are as defined above.
The ester starting material of formula XI may
be prepared by the general method as illustrated in more
detail in the disclosuxe and examples below for the
- 76 -
case in which R' is ethyl. The ethyl ester of formula
XI may be prepared by the following reaction sequence:
HC02Et + CH2-C02Et NaOEt
NHCHO 0 C.
NaOCH = C-CO2Et dry HCl (g) >
NHCHO r-o~C.
EtOH
CH2C12
NaHC03
NH HCl - or
NH3
(EtO)2CH-fH-CO2Et
NH2
By replacing the ethyl glycinate in the above
process with other desired easily cleavable esters,
starting materials having other suitable carboxyl-
protecting groups may be prepared.
Conversion of ester XI to the Schiff base XII
may he effected by condensing the ester with cinnamal-
dehyde in an inert organic solvent preferably with
heating and most preferably at reflux temperatures.
The condensation reaction is carried out in a suitable
inert organic solvent, e.g. ben~ene, ether or methylene
chloxide, in the presence of a drying agent, e.g.
~ - 77 -
-
- ::
`~ Na2S04, MgSC4, molecular sieves, etc., or, alter-
natively, by removing water azeotropically as with
~ benzene.
-~ The imine of formula XII is then condensed with
an azidoacetyl halide, e.g. chloride, in the presence of
A an organic base, preferably a tertiary amine such as
,
a trialkylamine, e.g. triethylamine, or pyridine. The
reaction may be conducted in an inert organic solvent
which may advantageously be a hydrocarbon or halo-
genated hydrocarbon solvent. A most preferred
,: .~
solvent for this step is methylene chloride. Best
results are obtained when the reaction mixture is
- cooled to about 0-5C. At the conclusion of the
reaction, the Schiff base solution is dried as with
Na2S04 and preferably evaporated to dryness.
Compound IV is obtained as a mixture of diastereo-
isomers having the formulae
~b'
N ~ 2 5 and
H
.~
C6H5
. ~ ~I
~ -- - ~ ~ O C 2 H 5
// N
¦ H C2R'
';6~
The stereochemistry of the azido and styrryl
substituents of compound IV has been shown by NMR
to be exclusively cis. The diastereoisomers of IV
need not be separated for use in the next step of
the reaction sequence.
After formation of the cls ~-lactam compound
IV, the ester protecting group R' may, if desired,
be removed, e.g. by saponification, and the corres-
ponding free acid esterified to incorporate into
compound IV another ester moiety R'. This optional
transesterification step may conveniently be used to
convert an ester such as a (lower)alkyl ester of
IV to a more labile and easily removable ester such
as a benzyl ester. Preferably, however, the desired
easily removable ester group is incorporated into
starting material XI so as to avoid the necessity of
a later transesterification step.
The cis ~-lactam ester of formula IV is sub-
jected to ozonolysis in the next step of the process to
produce the aldehyde of formula XVIII. Ozonolysis is
conveniently conducted in an inert organic solvent,
e.g. methylene chloride, with cooling, e.g. -50 to
-80C, in the presence of a reagent such as dimethyl
sulfide, dimethylsulfoxide or triethylamine which
serves to decompose the ozonide formed initially in
the rPaction.
- 79 -
Aldehyde XVIII is next selecti~ely reduced to form
- the alcohol compound XIII. Convenient reducing agents
for this step include diborane or me.al hydrides such
as sodium borohydride or zinc borohydride. The
reduction is conducted in an inert organic solvent
.~ .
~ which most ad~antageously is a (lower)alkanol such
-
as ethanol or methanol or tetrahydrofuran and pre-
. ferably with cooling to a temperature of about 0 to
-~ 10 ~ccording to one reaction route, alcohol xr~~
. ..~
is next converted to compound X~ by treatment with
~ acetic anhydride in the presence of a reagent selected
,~
~ from zinc chloride, trifluoroacetic anhydride,
.
titanium tetrachloride, boron trifluoride or stannous
chloride. The three reactants in this step are
preferably used in equimolar amounts and the reaction
may conveniently be performed at room temperature.
Compound XIV is hydrolyzed to alcohol XV by
treatment with acid, conveniently an aqueous solution
of a mineral acid, e.g. hydrochloric acid. The
hydrolysis is advantageously conducted at reflux
temperatures.
In the n~xt step of this reaction route, alcohol
XV is reacted with pyrrolidine to produce the enamine
. :~
compound of formula XVI. This step is conveniently
effected by refluxing the alcohol and pyrrolidine in
an i~.ert sol~ent, e.g. benzene, in the presence o~
an organic acid, e.g. acetic acid.
3~
..
In an alternatiye reaction route, alcohol XIII
~ is reacted with a methanesulfonating agent such as
;~ methanesulfonic anhydride or methanesulfonyl chloride
in the presence of an acid acceptor, preferably a
tertiary amine such as a trialkylamine, e.g. tri-
ethylamine, or pyridine, to form the methanesuifonyl
..,
derivative XVIII. The reaction may be conducted in
. .
an inert organic solvent, e.g. methylene chloride,
and is conveniently carried out at room temperature.
Compound XVIII is then converted by treatment with
.- acetic anhydride in the presence of a reagent selected
~ A ~;
from zinc chloride, trifluoroacetic anhydride, titanium
,,.~
tetrachloride, boron trifluoride or stannous chloride
to compound XIX which may then be subjected to base
; hydrolysis to form the enolate intermediate XX. While
the nature of the base is not critical in the hydrolysis
step, advantageously the base is an alkali metal hydrox-
ide such as sodium or potassium hydroxide.
Enamine XVI is then reacted with a methanesulfonating
agent such as methanesulfonic anhydride or methane-
sulfonyl chloride in the presence of an acid acceptor,
preferably a tertiary amine such as a trialkylamine, e.g.
j triethylamine, or pyridine to produce a methanesulfonyl
derivative of fo~nula XVII. The reactlon may be conducted
in an inert organic solvent, e.g. methylene chloride, and
is conveniently carried out at room temperature.
The methanesulfonyl derivativ~ of formula XVII is
next hydrolvzed by ~reatment with acid to the enol inter-
mediate of formula IXa. Advantageously the hydrolysis is
carried out by refluxing an aqueous solution of a mineral
acid such as hydrochloric acid with compound XVII.
I^`
, Enol intermediate IXa is cyclized to the azido ~-2-
isocephem intermediate Va by treatment with a base as
described above.
_ _
'$~
In the preparation of intermediate VII, the overall
- sequence of steps is as follows:
The ketal amine starting material of formula
XXII may be prepared by the following reaction
. sequence:
,~ .
:~
W-C ICI C02R~ ketalization~ W A---C C2R'
~4.1i~ O NOH O O NOH
W~ C C2R '
o o NH2
,1
1~4~
.,
T~e ester oxime may be prepared according to the
general method described by H. Adkins and J. Reeve,
J.A.C.S., 60, 1328 (1939). The carbonyl group of the
ester oxime is protected by ketalization with ethylene
slycol in the presence of acid, e.g. p-toluenesulfonic
acid. The ketal oxime is then selectively reduced as
with aluminum amalgam by the procedure described by
D. J. Drinkwater and P.W.G. Smith in J. Chem. Soc.
(C), 1305, (1971). The product may be recovered as
an acid addition salt, e.g. HCl salt, which may be
basified to give ketal amine starting material XXII.
An alternative procedure for preparing ketal
:
amine starting materials of formula XXII having
less labile ester groups, e.g. (lower)alkyl esters
such as ethyl or methyl, comprises selectively.
:
r:~
_
' :
~3~
reducing the oxime group of an ester oxime of the
formula
W-C C CO R'
Il ~ 2
O NOH
and subsequently protecting the carbonyl group by
ketalization. The reduction step may be conveniently
accomplished by catalytic hydrogenation and the ketal-
ization step is carried out as described above and
in the examples which follow.
Conversion of the ketal amine XXII to alcohol
XXVI is effected as described above in connection
with the process for preparing compounds of formula
II. Compound XXIV is obtained as a mixture of
diastereoisomers having the formulae
/ C6 5
3 \ H _ J
. .
O~
a~] ~XC~,J
and
/ C6H5
N H H ~¦
Tl ~
O ,~ ~
CO~R'
The stereochemistry of the azido and styrryl
substituents of compound XXIV has been shown by NMR
- 84 -
to be exclusively cis. The diastereoisomers of XXIV
need not be separated for use in the ozonolysis step
of the reaction sequence.
Alcohol XXVI is reacted with a methanesulfonat-
ing agent such as methanesulfonic anhydride or methane-
sulfonyl chloride in the presence of an acid acceptor,
preferably a tertiary amine base such as a trialkyl-
amine, e.g. triethylamine, or pyridine, to produce
the methanesulfonyl derivative of formula XXVII.
The reaction may be conducted in an inert organic
solvent, e.g. methylene chloride, and is conveniently
carried out at room temperature.
Enol intermediate X is produced by hydrolyzing
compound XXVII under acidic conditions. Examples of
suitable reagents for the ketal hydrolysis step are
trifluoroacetic acid, an aqueous solution of BF3
etherate and 50% perchloric acid in acetone.
Following the hydrolysis step, the enol inter-
mediate X is cyclized by treatment with base to
produce the azido 0-2-isocephem intermediate VIa
as described above.
Subsequent reduction as described above affords
the 7-amino 0-2-isocephem VIII.
Illustrative examples of the preparation of
compounds of the present invention follow. These examples
are given in illustration of, but not in limitation of,
- 85 -
6~;
the present invention. All temperatures are in degress
Centigrade. AR indicates Analytical Reagent grade. Other
abbreviations include TEA for triethylamine, THF for tetra-
hydrofuran, mm for millimole, TLC for thin layer chromato-
graphy and EEDQ is the amide bond forming reagent having
the structure
OEt
C2Et
- The 7-acylamido compounds prepared in the examples
which follow all have the hydrogen atoms at carbons 6 and
7 cis with respect to each other and, unless indicated, the
products are racemic mixtures in the sense that they are
composed of equal parts of the two isomers having the
following structures:
H H H H
> N ~ O O ~ N <
\~ C~O--
Description of the Preferred Embodiments
Example 1
- 86 -
CH3COC-C02Et H2~ 1096 Pd-C ~ CH3COCHC02Et
NOH EtOH-HCl NH2 HCl
Ethyl a-oximinoacetoacetate 1 (80 g.) lPrepared
according to the method of H. Adkins and J. Reeve, JACS,
60, 1328 (1939)] was dissolved in a mixture of ethanol
(EtOH; 200 ml. USP) and ethanolic HCl (70 ml. of 9.28
N HCl-EtOH; 1.25 equiv.). tAmounts of HCl greater and
smaller than 1.25 equivalents were found to give lower
yields of 2.~ 10% Palladium on carbon (8 g.) was added
carefully and the mixture was hydrogenated in a Parr
hydrogenation apparatus starting at 60 psig. After
absorption of the theoretical amount of hydrogen (1
2 hr.) the catalyst was filtered off and washed with
EtOH. The EtOH was removed in vacuo at 40 - 50 leaving
a thick red-brown oil. The oil was diluted with 8 vols.
of acetone (AR) with vigorous stirring. Yellow crystals
of the amine hydrochloride 2 separated out on cooling,
49 g. (55%), m.p. 122-123 (cor.) [lit m.p. = 114-116
uncor.; (W. G. Laver et al., J. Chem. Soc., (1959),
1474.] [Yields ranged from 45 - 70% according to the
scale of the reaction.] This material was used with-
-- 87 --
~ut ru~ther purl.ication.
~ CH~5COC~iC02Et ~3, ~2N~
: NH2~HCl CO ~ t
.
.
, ~o a mi~ture o~ ethylene glycol (1.75 kg., 2~.2
mole) and p-toluenesulfonic acid monohydrate (210 g.;
i.g5 mole) whlch had been warmed to 903, amlne hydro-
. .;
~ chloride 2 (460 g.; 2.54 mole) was added wlth vlgoro~ .
..~
~: ~echanlcal tlrring. The mixture w~s stirred for 40
m~n. at 90. The mixture wa~ then poured lnto a mix-
ture of water (2 1), conc. NX40~ (550 ml.), and lce
~.~
:.~ (1 1), and e~tracted four time~ with 500 ml. C~2C12.
, ~ The combined CH2C12 extracts were washed wlth brlne>
dr~ ed (~a2SO~), and evaporated to g ve 491 g. o~ a
dark red oll. The oll was dlluted to 1.8 1 with ~t20
(USP), cooled in an lce bath, and EtOH Bat Id with HCl
-~ gas waC added until the pH reached 2-3. The . esultlng
~olld wa3 co~lected by ~lltration and was~ed wi'h Et20 to
.
. yield 398 g ,~, hydrochlorlde as a li~ht ~ellowish solid (70~)
:n.p. 153-6~ (cor.). An analytlcal sample of hgd.o-
. chloride was recrystallized from 2-propanol-Ft20, white
. c~y~tal8, m.p. 1~8-1~0 (cor.~.
~ Reactlon time~ shor'er ar.d longer than 40 min.
at ~0 were examined and ~ound to ~i~e poorer result~.
-88-
l~
Ana1 Ca lc'd f~r C8~15N4-~Cl C~ 42-58;
~, 7.15; N, 6.21.
Found : C, 42.40;
~, 7.24; N, 6.37.
The rree ba3e of ~ ls convenlentl~ prepared
~rom it~ hydrochloride by ba~lcatlon wlth con~.
NH4CH and extractlon wlth CH2C12.
~0
Jl
~._ ~2N,~ 0C~ O bo~
, C~2Et, / C~2Et
,, s
:~ ~
,,.~ 0
~ 3~
L
. ,C02E~
..
A ~x~ure of keta~ am~ne 3 (123 g.; o.65 mole~,
cinnamaldehyde t8~-9 g.; o.65 mcle), and ~H~C12 (2.6 1;
AR-dr~ed over ~A~ molecular ~leve) wa~ r~fluxed tnrough
a Soxhlet ap~ratus ~cntaini~g 200 g, of 4A~ mole~ular
sle~e f or 2 hr . ~he C~2C12 was then rem~Yed on a ro-ary
¦ e~apcr~tor ~;~ 40 ~lth 'he ~lnal trace~ of ~2C12 belng
remotted by pumpln~; down to 0.5 mm. at 25" ~or 20
~r.~utes . N;~ lndlc~ted complete Pormat lon of lmlne
. 4 whlch was u~ed dlrectly ln the ne~ct ~tep.
a Crude ~mine 4 (ca . ~.65 mole) was d~ s~olved ln
C~I2C12 (~ }; AR drled o~er ~A molecular ~leYe), l~EA
(99.6~ m~. 1.1 equlv, ) waq adde~, and the solutlon
*; wa3 placed under N2 ~nd cooled to ~-4~ wlth an ice
bath. A solutlon o~ azldoacetyl chlor~de (85.19 g,
~c~ }.1 equiv.) in ~I~C12 t500 ml.) wa3 added with stlr-in~,
~-~y~ o~er 4 hr. The reaction mi~ture wa~ ~tlr~red overnlg;ht
at 25 2nd then reflux~d for 1 hr. The reaction mixcu e was
.. cooled, washed with 10% HCl, then with brine, an~ dried over
.~. Na2S04 to give 267 g. of a dar~c oil which N~ indica~ed
., .
~............ conta~ned 96 weigh~ % of 5. (245 g.; 98%).
.. ~ . ~
AnAl. sa;nple was recrystall~zed from methanol, wh~te
solld, m. p, 81. 5 - 82, 5 (cor . )
Anal. Cal~ 'd for C19~22N405: C, 59.06; H, 5.94:
N, 14 . 50.
Found: C, 59.08; H, 5.73;
X, 14.58.
1~ NaOE ~ N~
_.
--90-
L~ ~
Ethyl ester 5 (64.31 g; 0.168 moles) was
dissolved in 700 ml. THF in a 2 1. 3 necked RB flask
equipped with magnetic stirring, a thermometer, an
addition funnel and a reflux condenser. There was
added 670 ml. of 0.25 N NaOH solution (0.168 moles)
at such a rate as to hold the temperature around 25
(took 1 hr.). Stirred at 25 until TLC showed that
5 had completely reacted (0.75 - 1.25 hr.). The
reaction mixture was carefully acidified to pH 3
with conc. HCl, sat'd with salt, and extracted with
CH2C12 (3 times). The CH2C12 extracts were washed
with brine, dried (Na2SO4) and evaporated in vacuo.
The residue was dissolved in Et2O and extracted with
10% NaHCO3 solution until the extracts were colorless.
The combined basic extracts were washed twice with
Et2O, then carefully acidified to pH 3 with conc.
HCl, sat'd with salt and extracted with CH2C12. The
CH2C12 extract was washed with brine, dried (Na2SO4)
and evaporated to dryness in vacuo to give 51.86 g.
(86%) of 6 as a brown solid. Recrystallization from
benz~ne provided an anal. sample as white needles,
m.p. 131-1.5 dec. (cor.).
Anal. Calc'd for C17H18N4 5
H, 5.06; N, 15.64.
Found: C, 57.06;
H, 5.13; N, 15.78.
- 91 -
1~,~;3L~
N ~
.,~ 2~ u2C~20
.
- ' l
Carboxyllc ac~d 6 tl28.01 g; o.~58 mole) was
: dlssolYed ln CX2C12 (1 1.) and TEA (39.8 g; 0.394
. mole) was added lTne carbo~lic acld 6 referred to
i~i Wa8 the crystalllne ~olld, m.p. 131-131.~, which is Qne
. o~ the 130mers.]. The ml~ture wa~ cooled ln an lce-
~ salt bath to 3 and then a mi~ture OI' benzyl ch~oro-
_ ~ form2te (67.5 g. of 88.6 welght %; 0.394 mole) and
. ~ C~2C}2 (200 ml.) was slowly added keeplng the
react1on temperature at 3, ALter the7 add~tlon was
c~mplete, tAe reactlon ml~ture was stlrred at amblent
~emperature for 30 min. and then refluxed ~ently until
,
- . evo~utlon of C02 cea~ed (ca. 30 min.~. Wor~ed up by
w2shin~ wlth 10% HCl, 13% ~aX~03, brlne, drled (~a~S04)
- ! and evaporated to dryne~ in ~acuo to yield 161.10 g.
¦ (100~) of crude ~, ~ry~t~ zed from be~lzene-petroieum
e~her (~0 - ~0) to give 143.60 g. ~9~) of ~ a3 a llgh~
. belge solld~ m.p. 65.5 - ~6.5 (cor,~.
Anal. calc'd fo~ c2~.2~05: C, ~4~27; ~, 5.,9;
~, 12.4~.
Found: C, 6~,13; H, 5.36;
N, 12.48.
-92-
1~13~66
o~a3 C~ ~ 3
: C02~ H20 co
7 8
~.1
:
;~ Styryl ~-12ctam 7 (~6,30 g; 81.24 mm) ~mhe s~y~yl
-; ~^lactam ~ u3ed in thl~ expe~lment WG s prlnclpall~ one
~- o~ the po~qible l~omers.~ was dissolved ln CH2C12
;~ (~00 ml.), cooled to -50 to -60 ln a dry lce-acet~ne
,~
.~ batn, and ozonized untll a ~aint blue color appeared.
. ~ ~he solutlon was then ~lushed wlth 2 untll~the blue color
faded. (CH3)2S (~1.87 ml; 5 equ~v.) wa3 added to the
-~0 ~olutlon, which was then allowed to 810w~y reach
;~ 25 as the cooling bath gradually melted. Kept at 25
. under N2 overnlght then washed twlc~ with 1~ NaHC03,
twlce w~th brlne, dried (Na2S04) and e~apo~ted to
~ryness. ~hl~ pro~lded ~2.~2 g. o~ ~ an oil whlch
crystallized on ~tanding. Ihls materlal was slu-ried
with ether and riltered to pro~ide 18.84 g. (~%) o~f-
wh~te solid ~ m.p. 57-100~ (co-.). The ana~tlcal
sample was recry3tallized from e~her, whlte cry~tal3,
.p. 101-2 (cor.).
-93-
I
34~
Anal. Calc d for C17 18 4 6
H, 4.84; N, 14.96.
Found: C, 54.75;
H, 4.87; N, 14.89.
OH
N3~ J
O CH3 CO2CH20
C02CH2P
OSO CH
N3 J 2 3
,L I \~xo
C02CH20
Aldehyde 8 (43.15 g; 0.115 mole) was dissolved
in THF (400 ml; AR) and the resultant solution cooled to
-5 to -10 (ice-MeOH). NaBH4 (2.192 g 0.576 mole) was
added, with stirring, in three portions. After 25 min.,
TLC indicated complete reaction of aldehyde ~. The
reaction mixture was carefully acidified to pH 3 with
10% HCl, diluted with 100 ml. of brine, and extracted
with ether (4 x's 200 ml.). The combined ether extracts
- 94 -
.~
~ ~ 4~
,
,
:'~.
.~
~v~ we~e washed wlth brine (2 ~'s 150 ml.), drled (Na2S04),
j~ and evaporated to dryness in ~acuo. Thl~ provlded
48.7 g. o~ a as a red o~l (containlng some ~F) whose
IR and NMR con~lrmed the s~ructure ~ ~Epimer~z2tion
occura at the pcsltlon c to the ester group during
thls r~ductlon.~. Thl8 materlal wa~ u~ed a~ s~ch
~,
~n the next reactlon.
:-~ Crude ~lcohol ~ (42.37 g; 0.11~ mo~e) and TEA
:~ ~17,07 ml.; 0.~24 mole) were dissolved in CH2C12 ~400
~l. A~ over 4A molec~lar sle~e), placed unde~ N2
atmo~phere 2nd cooled to O to -5 (lce-MeOH). Methane-
: 3ul~0nyl chlor~de (14.15'g, 0.12~ mole) dls301Yed tn
~,3 C~C12 (~00 ml, AR) was added o~er 15 mlnute~. After
!~,., 1 hr. at am~ent temp~ the reactlon was ca. 80~ complete
~ (TIC). After 3 hours, the reaction mixture was washed with
:~ water and then with brine, drled over Na2S04 and evaporated
54 to pro~ide 56.1 g, of brown o~l. This oil was dissolved ~n
..,~
-;~ ~he ~inlmu~ am~unt of benzene and chromatographed ove, 7~0 g.
,
Gf actlYated aL~mina using EtOAc-Et20 (1:3) as eiuting solvent.
. 30 g. of pure crystalllnP mesylate ~ was obtained from the firse
l~ter of eluen~. 4.2 g, of sllgh~l~ lmpure ~esyl2'e
~B obtalned a~ a forerun. Tota~ yield _ 667~ fr~m 8.
Anal. sample w2~ crystalllzed ~ro~ ~enzene-ethe-, white
_ crys~2 lq, m.p. g7-9~ tcor.).
Anal, ~alc'd ~or C18~22N4C8S: C, 47.5i; ~, 4.88;
Found : C, 47,~6; X, ~.93;
3^
. ~13 4
N~ ~S2C~3 ISQ2CH3
~ 0 ~ 95~ TFA ~~ ~ O~
0~1 C~ o/, ~ C~
C2 ~ 0 CO2CH2~
. / 11
/
Base /
O
: 2CH20
-~
~ 12
-, ~
~ Ketal lO (~.19 g; 6.43 mm) wa~ placed ln a 'OO ml.
.", ,~
~hree-necked round bottom ~lask e~u~pped wlth ma~netlc
stlrrlng. ~5~ TFA (30 ml.) ~95~ T~A was prepared by
add~ng 5 ml. of water to 2 100 ml. graduated cyllnder
and dlluting to lOO ml. wlth glacial TFA.~ was added
and the so~ution was stirred at amblent temp. (ca. 25~
fc~ 2 hr . At th~ 9 p~lnt NMR examination o~ an allquot.
~rom the reactlon mixture ~howed complete reaction. The
mi~ture was dlluted wlth lO vols. Or brlne and extracted
~ t~es wlth 100 ml. (each) of CH2C12. I~e com~ined
extract~ were dried (Na2S04) and e-raporated to ary:~e~s
a cuo lea-~ln~ ~ .17 g, of 11 a s a hea~J ~rown oll .
_9O_
1~
. NMR conflrmed the ~resence Or enol 11.
ThlB materlal was used as such ~n the ne~t re-
action.
Crude enol 11 (de~cr~bed abo~e) tl2.02 g; ca.
29.44 mm) was di~301ved ln CH2C12 (100 ml.) and TEA
. (4.1 ml; 29.44 mm) added. The mi~ture wa~ re~luxed
under a CaC12 drying tube for 2 hr, then washed wi~h
10~ ~Cl, brine and drled (N~S04). ~aporatlon left
. - 8.56 g. of 1~ ~s a llght brown Qt 1. Thi`~ materlal
:; Wa8 taken up in CX2C12 and ~11tered thrcu~h C2. 100 g.
. of s~ 7iclc acid powder. Evaporatlon of the rl~tr~te
and Et20 wa3hings gave 6,58 g, o~ 12 ~80.5,~ rrom 1_)
as a ll~ht belge solid.
. A~ analyttcal.. sa~ple wa~ recryst~lllzed cnc~ ~rom
~: ether to gi~e whlte cry~tal~, m.p. 87-88 (cor. ) .
,:
:~ Anal. Calc~d ~or C15Hl~N404: C, 57.32; H, 4.49;
N, 17.83.
Found: C, 57.31; H, 4.58;
~, ~7.~7.
1~13~
O E2, P$ ~ 2~2CE20
12 / 1~
.
0CICE2CO~}~G /~0
O ~ 3
, . co2c}~20
.,
Azido 0-2-isocephem 12 ~201 mg; ~ . 64 mm) was dis -
sol~red in absolute EtOH (~5 ml.) J 87,~ PtO2 (100 m6.)
was added and the ml~ture was hyd~ogenated at atmospheric
pressure. The theoretical amount of hydrogen (for PtO2
reductlon) was absor'Ded ~n 7 min. and the reaction was
8topped to avoid hydrogenolysis o~ the benzyl ester.
m e ca'aly~t was filtered off and washed wlth 2 vol.
of Et~. Fvaporatlon of the EtC~ p-o~ri~ed 0.19 g~ o'`
a~ a yellowish oll. T~ showed no 12. T~.i3 ¢
~as used im...ed1ately ln the next step.
Crude amlne 1~ (O.l9 g; o.64 mm) ~as dlssolved in
C~2Ci2 ~60 ml.~ an~ phenoxyace'~c acld (PAA) (g7.4 mg;
0.6~ ~-.) and rEDQ (158 mg; o,6~ m~ were added. T~e
reactlon mlxture ~as allowed to stl- at 25 fo- 1 hr.
--98--
I
~nd ~hen lt was washed 2 tlmes wlth 1~ Na~C0~, 2 tlme~
wlth 10~ ~Cl, once with ~ vols. of ~rlne, drled (Na2S04)
and eYaporated to dryness ~B vacuo. m i~ provided 0.18 g.
or 14 a3 a yellowi~h 6um whlch was trltur2ted w~th dry
Et20, The ~t20 trlturant wa~ cool~d at 0 oYe~nlght.
. ~he resul~ant crystal~ were collected by filtratlon
_ - an~ washed once wlth petroleum ether (30 - 60) to
. glYe whlte cryst~ls Or 14, m.p. 1~3-1~5 dec. (cor.).
A~al Calc'd ~or C2~X22N206: C, ~5.39; H, 5.25;
N, 6.63.
. Found: C, 65.22; ~, 5.31;
:
~, 6.86.
,
.
'i ~OCH2CON~ /~q
~2CH20
14
~2' Pd-C
00C~2~
~2X
1~
_ g g _
iS~
Benzyl ester 14 (lOO mg; 0.2~7 mm) was dl~solved
ln a mixture of absolute EtOH (lO ml.) and l~n~ (7 ml.).
10~ Pd-C tlOO mg.) wa~ care~ull~ added and the mlx~ure
wa~ hydrogenated at atmospher~c pressure. Hydrogen
,~ uptake was complete after ca. 7 mln. m e catalyst
! ~ Wa8 ~t ltered o~f and washed once wlth EtOX. The EtOH
.. Wa8 remo~ed ln vacuo lea~lng g3 mg. o~ partly crystal-
line resldue. The resldue was crystal~lzed from acetone-
ether to provlde o~,-whlte cryst2l1s of ~, m.p. 1?1 -172
1 dec. (cor.).
:~t Anal- Calc~d ~or Cl6~l6N26 C, 57
N, 8.43.
. ~ Found: C, 57.67; H, 4.g7;
~3 N, 8.34.
A sample of compound 15 prepared above whlch can
be na~ed 7~-phenoxyacetamido-3-methyl-0-2-isocephem-4-
carboxyl~c acld (called BC-L8) a~ter sol~ltlon ln ~rater
:~ - and dllution with Nutrient Broth was L ound to exhiblt
the ~ollowing ~inlmum Inhlbltory C~ncentratlons ~.I.C.
~n mcg./ml. versus the indicated microor~anisms aQ
determ~ned by overni~,ht incubat~on at 37 C. by ~ube
dilutlon. One old, orally absorbed cephalo~por~n
~ cçphalexin) ~as lncluded.
--
-100-
-- , . . . . .
`:
-
-~ ~
M l.C. ln mc,/ml,
.
: Organ~sm 3C-L8 CeDha-
~i! }exin
D. pneumonlae A9585 .5.6
~5,9~ serum*
Str. Pyogenes A9604 .5.6
:~1 t~ gerum~
S. aureus Smlth~ A9~37 51.3
S. aureu~ Sm~th~ A9537 2 -2.5
~50~ serum
S . a ureu~ BX1633-2 A 9606 2
at 10- dil'n
S. zureus BX1633-2 A9~o6 32 2
at 10-2 dll'n
Sal. enterltldls1 A9531 8
~. coll ~ A15119 63 4
E. colit A9675 250 16
K. pneumonlae~ A9g77 ~2
K. pneumonlae~ A15130500 16
Pr. mlrabilis~ A9900` 16 4
Pr . morgan~ A 15 1535 >125
P8. aeruglnosa~ A9843A500 >125
Ser. marceccens~ A20019500 >125
Ent. cloac2e A9656 500 >125
Ent . c loa ca e A 9657 6~ 2
Erlt. cloacae A9659 500 125
S. aureus meth.-3 A15097 32 16
res1 st; at 10
dll ~ n
* 50~ Nutrlent Broth - 45,g Antlbiot~ c Assa~ Broth
~ at 10 L~ d1 lution.
- . t
,
. . ~
.
-101-
... .. . . . . . . ..
~ ~3.1346~i
Examole 2
~ ~9 1~ co2~20
. O NOH
' 16
. ~enzvl O;clm"no-Acotoacetate
The procedure was e~sentlally the same as that
de5cribed for the correspond1ng ethyl ester by ~.
;~ Ad~ins and ~. ~eeve, JACS ~0, 132~ (1938).
~ n 2 t~ree nec~ed one llter flask, ~itted wlth a
thermometer, a d.opping funnel and a magnetic ~tirrer
. . .
. ~rere placed 173 g. (0.9 mole) of benzyl acetoacetate
.3 [The benzyl acetoacetate was prepared as descr~ed by
.~
~7~ ~ ~a~er et al., i. Org. Chem. 17, ~1 (lg52)~ and l~O ml.
~ ~ of g}aclal acetic acid. The contents were cooled ln
;~ an lce-salt ba~-h and a soiution o~ 69 g. ~ mole) o~
.~ Rodium nltrlte in 130 ml. of water was ~dded o~er a
period ol half an hour; t~e temperature wa~ ~ept at
.~ O to 10 C. After the reactlon mlxture was ~t~rred
~or one hour at room temperature, 400 mi. o~ water
; Wa8 a~ded and the stlrring was cont~nued ~or an
.: a~di~ional two hours. The reaction mixtur~ was extracted
~hree ti~e w~ 20~ ml. portions ol diethyl ether.
. The diet~yl ether e~tracts were combined, washed once
~l'h water, thre~ t~mes wlth saturated ~odlu~n bicar-
bona~e ~olut~on and o~ce wi~h brine. After drylng
-lG2-
g~
over anhy~rous ~odlum sulfate, the dieth~l ether ~o-
lutlon was evapo~ated lea~ing ,6 a~ 2 clear oll whlch
. 8011dtfled upon trlturatlon with petroleum ether
(~0 - 6~J to give 186.5 g. (93.2%) of whlte olid,
}t8 NM2 spect-um was conslstent wi'h the assl~ed
structure. Generally the product was used as such
ln su~sequent reactlon but lt can be recrystalllzed
~rom toluene, m.p. 81 - 82 C.
,~ . .
,~
- C~3C_E-Co~CY20 -~ ,C~- C-C~CH2~
N~H ~ NOH
16 1
.... , ~enz~l Oxlmlno-Acetoacetate Fthvl~ne Keta
,~....................... ...
..
In a two llter flask fltted wlth a ~ean Stark
:~ water separator and a condenser w~re placed 1~6.5 g.
:
(0.85 mole) of benzyl oximlno-acetoacetate (-L7) ~
62 g. (1 mole) of ethylene glycol, 800 ml. of benzene
~reagent grade) and 2 g. of toluenesulfonic acid. T~e
r~actlon mlxture was boiled at reflux until 15 ml. of
wate~ was remoYea (3 hours). The benzene 30iution
was washed once wit~ szturated sadium blcarbonate
~olution and once with ~r1rle. A~ter drying over
anhydrous 30d~um sulfate, the benzene solutlon was
e~aporated, lea~lng 212 g. ~54~) of 17 as a ll~ht
yellow o~l. lts NM~ spectrum was consistent ~lth
I
1~134~;
the asslgned ~tructure. Generally the com?ound W2 3
used as such in sub~equent reactlon bu~ one o~ ~he
iSomer~ can be crystalllzed- ln 55% yleld from
toluene-petrole~m ether, m.p. 52 C.
~'
CK ~ II C2C~20 Al, Hg~ ~ O J
17 18
. ~ v~
'.'.:
,
:.~ ~}2~1 Amlno-.4cetoacetate ~th~lene Ketal (l8)
~The procedure w25 es~entlally the same as that
described ~or the reduction of unsaturated hydroxy-
~m~no ethyl esters by D. J. Drlnkwater and P. W. G.
..,; . -,
~ Smlth, J. Chem. Soc. (C), 1305 (1971).] ~Alumlnum
:^~. amalgam was prepared essentlall~ the same as that
~,,.k de~crlbed in "Vogel except the followlng modlflcatlons:
; A 5~ NaOH wa used.
B. ~he second washlng wlth ethanol was omitted.
C. Dry dlethyl ether wa~ used for wa~h1ng and most
of the ~ater mu~t be dralned.]
~ogel "Practlcal Organlc Chemlstry" ~rd E~ltion.
Longemans Green & CG., London ~19~7) p. 198.3
. A lu~nlnum ama lgam ~from 27 g . of a lumlr~um rO~ 1)
~reshly p.epared ~n a three-necked one l~ter ~lask
waJ covered wlth 500 ml. o~ dlethyl ether. Ihe rlask
--10~--
6 ~
was ~itted wlth a mechanlcal stlrrer, a condenser,
and a dropplng runnel. 132.5 g (0.5 mole) of
b~nz~l o~lmino-acetoacetate ethylene ketal (17)
ln 300 ml. of wet dlethyl ether was added dropwise
8t such a rate as to malntain bolllng at reflu~.
A~ter stlrrlng for four hours, the react~on m~xture
. .
wa~ ~iltered through a ~uchner funnel. The ~lltrate
was evaporated leaving 110 g. of 18 as a yellowish
oll. m e oll was plcked up ln 800 ml. of dry d~ethy~
:~ ether and dry hydrogen chlorlde was pas~ed ln to give
108 g. of whlte hydrochloride salt of ~8 wh~ch was
collected, m.p. 157-158 C.
~ To obtaln the ~ree base 18, the hydrochlorld~ salt
.~ ~as suspended ln 500 ml. of diethyl ether, concentrated.
ammonium hydroxlde was added wlth shaklng u~tll most of
. ~ the solid went lnto solutlon, then washed twtce with
.i,t~ ' brine. A,ter drylng o~er anhydrous sul~ate, the solvent
w2s e~aporated leaving 90 g. of 18 as a colorless oll
~71~). It~ NMR spectrum was conslstent with the
a3signed structure,
-105-
r- )
0-CH_CH-CH0
. CE ~ - CH C2 2 C02CH20
18 / 19
_ cpG~ /
: L~
,
:`' 0~
~ 2CH20
;- 20
..~
'`' ~"~ .
.~
. .;,
Schlff Base Formation: In a one llter flask fltted
w1th a Dean Star~ water separator and a condenser
,.,,~
were placed 70.3 g. (0.28 mole) benzyl a~lno-
~_ acetoacetate ethylene ketal (18), 37 g. (0.28 mole)
clnnamaldehyde and 7~0 ml. of meth~lene chlorlde.
. The mixt~re ~as bolled at reflux for halL an hour
. and then 400 ml. o~ methylene chlor~de was distllled
and remo~ed through the Dean Stark water separator,
The c~ncentrated. solution ~as ~irst drSed ~ver
2nhydrous sodium sulfate and then ev2por2tea completely
on an evspor2tor to drlve the reactlon to co~p~etlon.
6-
1~
The resldual,oily 19 W26 checked by NMR to ensure
complete Schlff base form2tion before contlnulng on
the ne~t step.
B-Iact2m Formation: The freshly prepared Schi~r base
(l~) was diluted wlth 600 ml. Or methylene chloride
snd cooled to 0 C. (lce-salt bath). [All the methylene
ch~orlde u~ed ln the cyclo addition reaction was reagent
;
grade whlch was ~irst dried over molecular sleve
(Type 4A) and then o~er anhydrous calc1um chlorlde.
r
31.1 g. (o.308 mole) Or trlethylamine was added and
.,
- ~ollowed by a ~olutlon Or 36.2 g. (o.308 mole) of
azldo-acetyl chloride ln 362 ml. of methylene chloride
-~ addlng dropwlse at 0 C. over a period of one hour.
r$ The ~eactlon mlxture was st~-red for an addltional
hour at room temperature and then evaporated on a
~lash e~aporator at reduced pressure while belng
heated on a ,5 C. water b2th; thls operatlon is
- ~i
nece~sary to ensure complete ~-lactam formatlon.
The resldue was ~l~uted with 500 ml. Or diethyl
ether and ~lltered. The flltrate was washed ~wice
~lth brine and dried over 2nhydrou~ sodium sul~ate.
Evaporation Or thls ~olution yl elded 117.~ g. (g4~)
: Or product 20. Its NMR and IR ~pectra were cons~stent
wlth t~.e assigned structure. ~enerally, the product was
used 28 such in subse~uent reaction ~ut one of the lsomers
can be crystall1zed from dlethyl ether.
-1~7-
~;~134~i~
Compound 20 is identical with compound 7 prepared in
Ex2mp~e 1 ~nd ~s reacted according ~o the procedures of
Exa~?le 1 ~o produce benzyl 7~^smino-3-methyl- A 3-0-2-
tso~ephem-4-ca:boxyl2te having fOrmulâ
. E~ -~
~ ~ H2N ~
.. , C02C~20
A m;~xture of amine 13 (430 mg.; 1.49 mmole), N-c~rbo-
benzoxy-Dt-)-phenylglycine (422 mg.; 1.49 mmoie), EEDQ
, .~
(368 mg.; 1.49 mmole) ant 30 ml. CH2C12 was stirred ât
25 f~r 1 ho~r. ~t was then washed with 10% HCl, 1%
~HC03 and brine and dried over Na2S04. Evaporation
n vacuo ga~e 0.85 g. of a wh~te foam which was crystallized
~ fr~m ether-pentane and then from MeOH.
: ~ An~l. Câlc 'd for ~31H2gN307.Q.5 H2Q: ~, 65.95;
_ H~ 5.36; N, 7.44.
Found: C, 66.12;
P., 5,3Q; N, 7.S7.
The white foam was characteslzed by I~ and ~M~ to be
~he N-psotPcted compound of formula
H
~-CIHCQN~ ~
~02CH2~ ~ N ~ CH3
co ~ca
&-
bb
. A ~Xtll, e of the above N-2r~tected in.erme~ e
(2&; ~:g.), oOO mg. cf 3G7~ iatc~3ceo~s ea~eh a~.d 10 ml.
of e~ hanol was hydsogenated at 25 &t 50 psig in a Par~
.1
hyd:ogena~or. Af~er 0.5 hour, ehe cae~lyst was f~leered
off and the ril.rate was eYaporated to dryness in ~tacuo.
Tbe r2sut tant . esids~e W2; covered w~th CHC13 and then
HC~ gas WâS ~nt.oduced. Addit~on of ether produced a
prec~ltaee which was filtered off and dried in vacuo.
The product, a yellow~sh solid, decomposed at 177-182~
(~ orrected) and was charzcterized Dy ~R and N2~ as 7~ -
~D-~-ami~?h2nylacetamidoj-3-methyl-~3-Q-2-isocephem-4-
ca,ba~yl~ c ac. d ~ydrochloride (called BC-Lg) of the
formula
H ~1
,~-C~-CO~ `o
o~ L ~ CH3
' C2E~
'
Anal Calc 'd fos C16H17N30s.~CL'H2O: C, 4g.81;
H, 5.22; N, 10.8~.
Found: C, 4~.76;
~, 5.21; N, 9.11.
A sas~ple o~ BC-I.9 after solution in water and dilution
with ~-utr~ ent Broth was found to exnibit the followi ng
Minim~;l Tnh~bleory Concent~ations (M.I.C.) ~n mcg.lml.
v~ssus th~ indicat2d ~icroorganisms 25 dete~lned by over-
night ~ncubaeion at 37C . by tube dil~t~ on. O:le ol~, o-a 1~-
ab30rbed cephaiosporin (ce?hale~cin) wzs incl~d~d,
)
~ 134~;
,,
Table 2
~ I . 1, C . in mc ~ . /ml .
0,anism BC-T-9 Cepha-
lexin
I) . pne~monia e A 9 58 5 . 5 . 3
: ~5Z s er~n*
s e- . pyog enes A9604 . 5 . 3
-~5% serum*
S. ~ureus Smith ~ A9537 2 1.3
.~ I S. aureus Smith ~ A9537 16 2.5
. ~ 50% s erum
S. aureu BX1633-2 A9606 8
~,~. at 10 ~ dil ' n
S. sureus BX1633-2 A9606 32 2
. ae 10-2 dil 'n
S. aureus m~ch.- A15097 32 i6
' resist; ~e 10-3
: .dil 'n
Sal. enteritidis ~ Ag531 16 4
E. coli Juhl $ A15119 32 4
E. coli ~ A967 5 63
. I ~. pneumoni~e ~ A9977 16 4
K. pneumonia e ~ A15~3a 63 16
~r. m~rabilis ~ Ag900 63 8
Pr. morganii ~ A15153250 >125
Ps~, acruginosa ~ A984~A>500 >125
Ser. mareescens ' A20019500 ~>125
. Ent. c~oacae Ag656 500 >125
E:nt. cloac~e Ag657 32 4
Ent~ cloacae Ag659 125 ~125
.,
* 50% Nucriene Broth - 4j7. Antibiotic Assay 3.oth
$ s t 10-4 ~ st ion .
346
Exam~le 3
7B-Amino-3-methYl- A3~0-2-isocephem-~-carbcxYl~c ac~d
.
H H
. H2NW--
, ~ ~ CH3
, CQ2H
A m~xture of benzyl 7B-azido-3-methyl-~3-0^2-isocephem-
: 4-car~oxylate (314 mg.; 1 mmole), 30% Pd-diatom2ceous earth
~'
:- (274 mg.) and 25 ml. of ab601ute EtOH was hydrogenated at
. 25 and atmosp~eric pres6ure. ~ydrogen uptake was complete
. after 20 mlnutes. The reac~ion mixture was then warmed to
~. ~
. 40', the catalyst was filtered off and washed with l volume
~ of EtO~. The com~ined filtrate and washings were evaporated
'-'b
to dryness in vacuo to provide 140 mg. (71~) Oc wh~te
..
pcwdery residue wh~ch was identified by IR and NMR 85 the
title product. Decomp. >ca. 209 (cor).
Anal~ Ca~c'd for C~Hl~N204~0.5~20: C, 46.38; ~, 5.35;
N, ~3.52.
Found: C, 46.86; ~, S.3S;
~, 13~58.
A samp~e of the a~ove compound (called BC-L61) was ~cund
~o ~nhi~it S. cureus A9537 at a concentration o, 12S mcg.lml.,
E._coli A151~ at a concentration of ~i2S mcg.¦~l., D. pneu-
moniae A9585 at a concentration cf >8 mcg./ml. and
at a conc2n~ration of >8 ~cg . Jml .
Example 4
BenzYl 7B-Amino-3-methYl-~\3-o-2-isocephem-4-carboxylate
¦ H H
: N ~ CH2Cl2 ~2N ~
C02CC2H~ ~ 3
C02CH j~
12
H2S gas was bubbled into a solution of 2.0 g. (6.35
mm~tes) of benzyl-7~ -azido-3-methyl-~3-0-2-isocephem-4-
carboxylate (12)~4.2 ml. (30 mmole) tr~ethylamine, and 50
: ml. of A~ methylene chloride contalned in a 100 ml. 3 necked
flas~ equipped w~th a condenser, a gas inlet tube and
...
magneeic stirring. The solution color changed from color-
les8 to orange and 8 gas (N2) is evolved. TL~ after 20
! minutes showed that the reaction w~s co~plete. The reaction
-~ mixture was evaporated to dryness and the resulting yell~w
residue was shaken three times with a 1:1 ~ixture of 10%
j :
aqueous HCl and ether. Almost 811 of the residue goes
.
into solueion. The aqueous layer was separated and the
ether layer (yellow colored) was washed with l~t. a~ueous
~Cl. The combined ~Cl phases were washed once with ether
~nd the~ carefully alk~lized wieh solid NaHC03. The
~lkali~ed aqueous phase was extracted ~wice with C~2C}2
The C~2~12 extrzcts were combined, washed twice with satura-
ted brine, dr~ed (~a2S04) ~nd evaporated ~o dryness in ~'2CUO.
-112-
This provided 1.25 g. (68%) of a gummy residue (some blac~
impurities) which crystallized upon standing overnit-e.
NMR on this material indicates a purity of at least 95%.
The solid could be recrystallized from ether to give a
white solid, mp. 91-92 (cor).
Anal- Calc'd for C15H16N24 C, 62-49; H~ 5.59; N~ 9-72-
Found: C, 62.54; H, 5.51; N, 9.65.
Example 5
,. 7~B-Phenoxvacetamido-3-benzyl-~3-o-2-isocephem-4-carbox~lic
acid
--- 00CH2CONH - -
CH2~21
. C02H
0CH2COCl + EtO-Mg-CH(COOEt)2 ~~~~ 0CH2COCH(COOEt)2 ~+
Et
The ethyl r-phenylacetoacetate was prepared after the
procedure describedl in 40~ yield. B.P. 0.005 mm 103-105.
.3 `
200CH2cOcH2cOoEt + ~CH2H ~ ~ 0CH2cOcH2cOoBz
A mixture of ethyl r-phenylacetoacetate (166 g.; 0.76
mole~ and benzyl alcohol (100 g.; 0.92 mole) was immersed
into an oil ba~h, preheated to 170, and with stirring the
ethyl alcohol produced was distilled off. With an aspirator,
a forerun fraction (B.P. 100 mm 65-80) was removed and
1. G.R. Ames and W. Davey. J. Chem. Soc, 1957, 3480-37.
-113-
1~ 1~ 4~
fin~lly the residue was dis~lled 8t l~w pressure. B.P.
0,002 mm 155-157. By recycl~ng the forerun, 8 further
~u~nt~ty of pure compcund wa6 obeained. Overall yietd was
171 g. ~84%).
HN02
,0CH2COCH2COOBZ ,0C~2C~C -COOBz
54 NOH 55
_ ~
A 801ution of benzyl r-phenylacetoacetate 54 (85.5 g.;
0.32 mole) ~n glacial acetlc acid (400 ml.) and water
(150 ml.) W8S cooled to 5 in an ~ce bath and ~hile stirring
vigorously, to $t was added dropwise in 4 minutes a solution
of sodum n$trite (2~.5 g.; 0.37 moIe) in water (lOO ml.).
The react~on tem~erature rose to 16C. and was st~rred w~th
cooling for 30 minutes more. The cooling bath was remoYed
. and st~rring continued for 2 hours. 800 ml. of water was
sdded and the solutlon was extracted with 3 x lOO ml.
C~2C~2. The combined extracts were wa6hed with water and
brine, dried over Na2S04 and evaporated, leaving 92.50 g.
o~}. Thi~ was crystallized in 90 ml. CC14 to give l~ght
yel~w crystals 52.80 g. (5~,), m.p. 69-70C.
0CB2-~OC - COOBZ +OH ~ 0C~2 -~C~ - C-COOBZ
A mlxture of oxime 55(5.~4 g.; 2Q mm)7ethy~ene glycol
(1.36 g.; 2~ mm) and p-toluenesulfonic acid monohydra~e
.5g g.~ ~n ~enzene (lQO ml.; A.R.) was refluxed over a
-114-
1~134~
Dean-Stark water trap for 3 1/2 hours. It was cooled, and
poured into 100 ml. saturated NaHC03 and extracted with
benzene. After the organic phase was washed with water,
dried oYer Na2SO~ a~d evaporated, 6.70 g. of an oil was
obtained. It was crystallized in 20 ml., CC14, and gave
4.0 g. (57%) light yellow solid, m.p. 90-92~C.
~,
2 / \ 1I COO Al/Hg ~ ~ 2 /
1~ 56 - ~
Alllm;num foil (6.9 g.; 255 mm) cut into small strips andi
loosely folded, was covered with 5% NaOH and allowed to
react for 2 minutes. It was decanted and washed successively
with water and 95% EtOH, th2n covered with 2~ mercuric
. .
chloride, and allowed to react for 2 minutes. After decanting,
it was washed with water and ether, then covered with "wet
~ ..
ether". To this amalgam with stirring was added an ether
solution of the "oximinioester", t29.5 g.; 8S mm) in ether
.,.. . . _ . , . . . . . ., ... . -
(600 ml.). There was a mildly exothermic reaction and after
the addition was complete, it was refluxed for 2 hours. It
was cooled, filtered through celite and extracted with 4 x
~~ 100 ml. 10% HCl. White crystals separated from the a~ueous
phase and were filtered, washed with cold water and dried to
give 29.0 g. solid, m.p. 181-183 with decomposition.
Recrystallized from EtOH~ether, m.p. 182-184 with decomposi-
tion. The free base was obtained by suspending the hydro-
chloride in water and alkalizing with cold concentrated
:i~
NH40H. Yield 100%.
- 115 -
, ,
~ 3~
!
~nal. Calc 'd. fos Clgl~22N04 ~HCl: C, 62. 72;
P., 6.0; N, 3.8~.
Found: C, ~2.83;
~, 6.14; N, 3.84. _
0C~20~; CH-COOBz 1 0 ~
COOBz
li3CH2COC lN3 ~ ~ f 5 8
: ~9 008z
,_
,
.~ ~e~al-amine 57 ~56.70 g.; 0.173 mo~e) was dissolved in
dry CH2C12 ~600 ml.) and eo it w~s added c~nnamaldehyde
(23.0 g.; 0.173 mole). The solution was refluxed for 30
minu~es ~nd the solYent was removed on the aspirator. The
.e8idue was redissolved in CH2C12 (600 ml.), the flas~ was
fitted with a Dean-Star~ wster trap, and the solvent
rerluxed whlle 300 ml. of CH2C12 uas coLiected and continu-
ously remo~ed through the tr~p. The residue was dried
over Na2so4 and e~aporated eo dryness leaving 77.32 g.
light yellow oil~ Thi~ W~ redissolved in CH2C12 (300 ml.),
~riethylamine ~27 ml.; 0.19 mole) was a~ded and while stirring
and cooling a . 3 -5C . in an icP-bath there was added ~ropwise
8 solution of szidcacetyl chloride (22.~ g.; 0.19 moie) in
CY2C12 (300 ~l.),addition belng done sver 2 hours, It wa~
k~pt at room ~mper~ture unde~ nicro~en for 16 hour~, and
- 1 1 5 -
~ J
refluxed for i ho~r. The solutlon was cooled, washed with
~ 7. HCl, then with brine, dried over N~2S04 and evapo~ated
.
.~ to give 90.35 g. It was used as such with no further
pusif~cation.
.,.
i N3~ a, o3 N3 - CH0
r 0~-~O 15 b) (CH3)2S~ ~ ~ 0 ~ ~
COOB~ 60
. Styryl ~-lactam 59 (11.0 g.; 21 m~) was dissolved in
~ C~2C12 (150 ml.) and ozonized at -6~ until a blue color
"G_ ~ppeared, then 2 W88 uset to flush away the excess ozone.
To the solution was added 7.7 ml. (1~5 mmole) of dimethyl
- ~ulfide and the cooling bath was allowed to warm up to
25C. sp~ntaneously ~n 5 hours. The solution was kep~ at
2S for 16 hours then washed with 1% NaHC03 and brine,
'3~'; dried over Na2S04 and evaporated to dryness. It was tritur-
. ~ted with petroleum ether t30-60) and the residue kept at
0.05 mmlHg snd 45C for 16 hours. This removed al$ the
benzaldehyde, and left 8.07 g. oil. ~t was used as such
,
without any further pur~fication.
,
H ~I H H
3~D ~I =~
60 C008z 6~ COOBz
A ~olution of aldehyde 60 (2.1 g,; 5 mm) in THF (50 ml.;
-117-
1~1;3 4~;
ls
A.R.) W25 cooled to -5 in an ice-salt bath snd while
.~ stirr~n~, to it was added sodium borohydr~de (0.1 g.;
2.9 mm), 811 at once. I~ was stirred at 0-5 for 30
m~nu~es, ~hen the cooling b~th was removed and stirring
continued at room temperature for 30 m~nutes. It was
carefully acidified with cold 107. HCl, saeurated with
~,
~odiiu~ chloride and extracted with ether. The ether phase
was w~shed with water, and br~ne, dried over Na2SO4 ant
i~,, .
evaporated to g~ve 1.88 g. oil. It was purified by chrom-
aeography on silica gel ITI, eluting with etherJpetroleum
9 ethe~ 2:1.
H H
N3 ~ H CH3SO2cl. ~ SO2CH3
~ N ~ ~ N ~ ~r
- 61 COOBz . 62
~ ~ COOBz
A mixture of alcohol 61 (1.10 g.; 2.6 mm) and triethyl-
j,i
amine (0.29 g.; 2.85 ~m) in CH2C12 (25 ml.) was cooled to
0C. and with st~rring undPr nitrogen to it was added drop-
wise a solution of methanesulfonyl ch.oride (0.33 8.; 2.85
mm) in CH2~ 10 ml. ) . It was stir2ed at 0 for 15 minutes,
then st room temperature for 1 hour. It was washed with
wster then with br~ne~ dried over Na2S04 and evsparated to
gi~e }.36 &~ oil. It wss used a~ such with no further
purification.
-118-
~ ) ~
~ --
~3
N H N3 ~
62 63 COCBz
~ ,_
The ketal-mesylate 62(1.36 g.; 2.5 mm) was d~ssolved
in ~5% t~fluoroacetic acid ~lS ml.~ snd stirred at 5~-55
for 2 hours on an oil bath. It was poured ~neo br ne and
extracted with CH2C12. After washing the organic ex~racts
with water and drying over Na2S~4, the solvent was re~oved
on the aspirator and left l.2~ g. red oil. No further
pur$fication was attempted.
; ~ K B ~ > ~
63 COOBz 64 C008z
A mixture of ~rude enol-mesylate 63 (5.4 g.) and tri-
ethylamine (2 ml.~ in dry C~2C12 (100 ml.) was refl~xed
for ~ bours. lt was cooled, washed with lO% ~Cl and water,
.
drie~ ovPr Na2S04 and evaporated on ~he aspira~or to give
4,24 ~. oil. This was purified by chroma~ography on 2~0
, g. 0~ ~iLica gel ~I~, elut~ng with e~her/pe~roleum ether
2:1. The ~-re compound 64 crysta11ized, m.p. 117-118-.
-119-
~ 4
P H
~r H25 H2N ~ ~
64 65 COOBz
A mlxture of "a~ito-isocephem" 64 (0.49 g.; 1.25~m~
,
2nd ~r~ethylam~ne ~0.~ ml.; 6.5 mm) in CH2C12 (50 ml~) was
cooled in sn ice bat~ and while being stirred, was satu~s;ed
with H2S. The coollng b2th was removed and there was gas
.
evolution which subsided in 10 minutes. At this p~int,
T.L.C. showed no starting material remained. Atte~pts to
extract the amine from ehe solution as its hydrochloride
f~iled 8S i~ is more soluble in CH2C12 than in water. The
C~2C12 solut~ on of the free base was dried over Na2SO4 and
e~aporated on the a6pirator to leave 0.40 g. of a semi-
~ol~d. It was used as such with no further purific~eion.
~ ~ ~QcH2c~h~ H
H2~ OCH2COOH ~
COOBz 66 COOBz
A ~olution of "a~ine-isocephem" 65 ~0.48 g.; 1.25 ~m),
phenoxyacetic acid (0,19; }.2S ~m) and EEDQ (0.31 g.; 1.25 ~m)
in CH2~12 ~100 ml~) was stirred st room tem?erature f~r 16
hours. I was washed with 1~l. NaHCO3 solution~ then with
~r~ne~ dried cver ha2SO4 and evapora~ed on the aspirato.
;o leave 0.56 g. of a slightly yellow gum, ~t was used w5 eh
no furthe~ purification~
! -120-
1~134~
~2CO~ ,~ocx2co~ _
0 N ~ ~ ~ ~ N
66 C008z 67 OOH
The "isocephem co~pound" 66 (0.49 g.; 1 ~m~ was ~issol~ed
~n ethyl acetatc ~100 ml.) and glacial ac~eic acid (10 ml.),
. 20% Pd(OK)2 on carbon (0.50 g.) wa~ added and the mixture
I ~as agitated on a Paar zpparatus at 60 psl of ~2 for 2 hours.
S~ , The sol~d was filtered off on celite and the fil~r~te
, evaporated to dryness. The residue was e~tr~cted with
~ sat~lr~ted NaH~03, the aque~us phase was acitified with
,i~ ; 10% HCl and extracted with CH2CI2, This was then washed
-?~ ' w~th water, dried o~er Na2S04 and evaporated to dryness.
~ The resul;lng solid was recrysta~lized from benzene and
,~ .
,~ gz~e uhite cryseals, m.p. 123-125 with decomposition.
Anal. Calc'd. for C22H20N26 C, 64-70; H~ .9 ;
N, 6.86.
Found: C, 64.78; H, 4,~7;
~, 6.80.
A ~ample of co~pound 67 pre~ared ahove w~ich
; can ~e na~ed 7~-phenoxyac~tamido-3-benzyl-~3-~-2-isocephem-
4-c2,~oxylic acid (also called BC-~17) after solution in
watPr and dilution with Nutrient Broth wa~ found to exhi~it
~h~ fQllowLn~ Minimum Inhibitory Conc~nt.stiQns ~M.I.C.)
1~34~
in mcg./ml. versus the indicated microorganisms as deter-
mined by overnight incubation at 37C. by tube dilution.
Cephalexin was included as a comparison compound.
,~,
.,.
..
.
-122-
., .. _ , .. . . . .. . . . . .. ... ..
. 1~
. Lable 3
M.I.C. in mc~./ml.
~ Or~anism BC-L17Cepha-
i lexin
¦ D, pneumoniae A9585 .25 .16
i ~5% serum*
se . pyogenes A9604 .25 .16
~5% serum*
S. aureus Smith ~ A9537 .25 .6
; S. aureus Smi~h ~ A9537 1 1.3
f ~so% serum
S. aureu~ BX1633-2 A9606 8
S. aureus ~X1633-2 Ag606 >125 2
~t 10-2 dil'n
5. aureus meth.- A15097 125 16
res~st; at 10-3
dil~n
S~l. enteritidis ~ A9531 32 2
E. cali ~uhl ~ A15119 ~125 8
E. coli ~ A9675 >125 16
R. pneumoniae ~ A9977 ~12S
K. pneumoniae ~ A15130 >125 16
Pr. mi,a~ilis ~ A9900 >12S 4
Pr. morganii t AlS153 >12S >125
Ps. aeruginosa ~ A9843A >125 >125
Ser. marcescens ~ A20019 >125 >125
Ent. cloacae Ag656 ~125 >125
Ent. cloacae A9657 >125 4
Ene. cloacae A965g >125 >125
* 50% NutrientgrOth - 45% Ant~iotic Assay Broth
at 1~-4 dilut~on.
-12~-
~ ?
~am~le 6
7~-Phenoxyaceeamido-3-~hene.hyl-~3-0-2-~soce~hem-4-
ca~boxYlic acid
H
~ ~ 2CO~o
,~ ~1 CH2CH20
C~2H
~2CH2~Br ~ CN-CH2-COOEt --> 0CH2CH2- C--CH2COCEt
`~; N~
¦ ~ > 0ChzCHz~ C~2COOEt
P~enylmagnesium bro~ide was preparedl in the usual
way from magnesium (24.30 g.; 1 ~ole), phenethylbromide
: . .
(2~4 g.; 1.1 moIe) and a trace of iodine in ether ~250 ml.;
A~). While maintain~ng the reaction temperature at 25-
3~C., to it was added ethylcyanoacetate (4~.2 g.; 0.25
~ole) a~d the result~ng solution was seirred at room
~;,t ' temperature for 24 hours. lt was decomposed with saturated
; ~m~onium chloride, 10% HCl and wzter and the phases separ-
~ted. The organic extract was treated with 10% H~1 (Z50
ml.~ and st~rred v~gorously for 3 hol~rs. The organic phase
. was wzshed with ~rine, dr~ed over Na2S04 and evapora~ed
: on the aspirator to give 83.5 g. oil. Fractlonal distil-
lation gav~ 12.67 g. (21Z) pure product. B.P, 0.1 millimeeer
~4 122~C,
1. G. ~. AndPsson e~ ,A.C.S. 67, 21~7-2200 ~1945).
-124-
-~?
. 1~
CH2~ C~2c0oEt ~ ~CH2O~ ... ~ ~CR2CH2lCH2COOBz
~ ' O O
A ~xture of eehyl r-benzyl&cetoacetate (12.56 g.;
50 m~) ana benzyl alcohol (8.1 g,; 75 mm) was im~ersed
~neo an oil bath preheated to 170C. and stirred. Afeer
e~hanoL had been d~stilled off, the exress benzyl alcohol
was removed on ehe asp~rator and finally the residue was
,,
. c~st~l~ed. ~.P. Q.oi millimeter, 160-163. 6.15 g. p-~r~
.~
~ pr~duct was obtainPd.
~. . .
HN~
~Cx2~2cocH2cooBz ~ CH2CH2C:O~j-COOBz
68 ~g NOH
_ ~
Tc e sclution of benzyl r-benzylace~oacetate ~37.0 g.;
0.13 m~le) ~n glacial acetic acid (~0 ml.) was added drop-
. .
W~62 in 1 hour a solution of.sodium nitrite ~10 g.; 0~143
m~le) in water (50 ml.). The reaction temperature was
kept at 24-30C. It was stirred ~n add~tional hour after
the addi~ion then dilu~ed with water ~10~ ml.), and
extracted w~th ether. The organic ex~ract was washed with
water and w~th 1% Na~C03 unt~l the washings were basic, then
w~th brine. Lt was.then dried over Na2S04 and evaporated
on the aspirator to lea~e 40.1 g. of a light yell~w oil.
It was uscd as such with no further purification.
~ r~
. 0C~2C~ C~C-C00Bz ~ t ~ 0CX2CH2~ C008z
A ~ixture of oxime t8.48 g,; 27 mm), ethylene glycoL
('.85 g.; 30 m~) and p-t~luenesulfonic acid monohydrat2
I
~134~
(0.85 g.) in benzene (100 ml.; AR) was refluxed over a
Dean-Stark water trap for 4 hours. It was cooled, poured
onto saturated NaHC03 and after shaking well, the phases
were separated. The organic phase was washed with water
and brine, dried over Na2S04 and evaporated on the aspir-
ator to leave 9.4 g. of an oil. It was used without
further purification.
0CH2CH2 -/Cb C-COOBz / g > 0CH2CH2 -/C\- CH-COOBz
~ NOH \__/ NH2
Aluminum foil (27 g.; 1 mole) cut into small strips
and loosely folded was covered with 5% NaOH and allowed to
react for 2-3 minutes. It was decanted and washed success-
ively with water and 95~ EtOH, then covered with 2~ mercuric
chloride and allowed to react for 2 minutes. After decanting,
it was washed with water and ether, and finally covered
with "wet ether". To this amalgam with stirring was added
an ether solution of the "oximinoester" 70 (43 g.; 0.12 mole)
in ether (300 ml.). There was an exothermic reaction and
after it subsided, the system was refluxed for 4 hours.
The inorganic material was filtered on celite and the
filtrate shaken well with 10% HCl (100 ml.). White crystals
separated and were collected by filtration, washed with
ether and dried in a dessicator to give 54.0 g. solid,
m.p. 186-188. The free ~ase was obtained by suspending
the solid in water, carefully alkalizing with cold concen-
trated NH40H and extracting with CH2C12. After
'
- 126 -
,
g~
evaporation of the solvent, 27.91 g. of a yellow oil was
obtained.
2 2 ~C\~ IH_COO~Z + ~ ~ C~
71 COOBz
N3 H H 0 72
~_ _~/
N 3CH 2 COC l F~
COOBz
~
A mixture of "amine-ketal" 71 (27.6 g.; 81 mm) and
cinnamaldehyde (10.7 g.; 81 mm) in CH2C12 (500 ml.) was
refluxed over a Dean-Stark water trap while 200 ml. solvent
was removed. By replacing the solvent removed with fresh
one, a further 3 x 250 ml. fractions were removed also.
Finally, the residue was evaporated to dryness on the aspir-
ator and pumped down at 0.05 millimeter/Hg. and 40C. for 10
minutes. The residue was re-dissolved in CH2C12 (250 ml.~,
triethylamine (11.9 ml.; 85 mm) was added and while stirring
and cooling in an ice bath, to it was added dropwise in
2 1/2 hours a solution of azidoacetyl chloride (10.15 g.;
85 mm) in CH2C12 (100 ml.). It was kept at room temperature
under nitrogen for 16 hours and refluxed for 1 hour. The
solution was cooled, washed with 10% HCl, then with brine,
dried over ~a2SO4 and ~vaporated on the aspirator to gi~e
44.77 g. red oil. It was used as such with no further
purification.
- 127 -
~3~
~3
COOBz
74 COOBz
Styryl ~-lactam 73 (6.7 g.; 12.5 mm) was dissolved
in CH2C12 (150 ml.), and ozonized at -78 until a blue color
appeared, and then nitrogen was used to flush away the
excess ozone. To the solution was added dimethyl sulfide
(4.5 ml.; 65 mm) and the cooling bath was allowed to warm
up to 25 spontaneously. The solution was kept at room
temperature for 16 hours then washed with 1% NaHCO3 and
brine, dried over Na2SO4 and evaporated to dryness. It
was then pumped down at 0.05 millimeter/Hg. and S0C. for 20
hours to remove most of the benzaldehyde. The residue was
chromatographed on 250 g. of silica gel III, eluting with;
first ether/petroleum ether 2:1 (to remove benzaldehyde)
and then with ether.
N 3 ~ H CHO N 3 H H
O
74 COOBz 75 COOBz
~~ ~
A solution of aldehyde 7~ (4.1 g.; 8.8 mm) in THF
(100 ml.; A.R.) was cooled to -5 and while stirrin~, to it
was added sodium borohydride (0.17 g.; 4.5 mm) all at once.
- 128 -
46~;
It was stirred at -5C. for 1 1/2 hours, then carefully
acidified with 10% HCl, saturated with sodium chloride
and extracted with ether. The ether phase was washed with
water, and brine, dried over Na2SO4 and evaporated to give
3.8 g. oil. It was used With no further purification.
N H H N H H
Mes
N
COOBz 76 COOBz
A mixture of alcohol 75 (3.8 g.; 8.3 mm) and tri-
ethylamine (1.25 ml.; 9 mm) in CH2C12 (50 ml.) was cooled
to 0, and with Stirring under nitrogen, to it was added
dropwise, a solution of methanesulfonyl chloride (1.0 g.;
9 mm) in CH2C12 (25 ml.). It was stirred at room temperature
for 1 1/2 hours, then washed with 10~ HCl water and brine,
and dried over Na2SO4. It was then evaporated to give 4.3
g. oil. This was purified by chromatography on 250 g.
si~ iCa gel III eluting with ether/petroleum ether 3:1. 2.05
g. of pure mesylate was obtained.
n~ ~ ~ 3 ~ ~
COOBz
76 COOBz ~
Ketal-mesylate 76 (2.05 g.; 3.7 mm) was dissolved in
- 129 -
.~
4~
95% trifluoroacetic acid (200 ml.) and stirred at 50-55C.
for 2 hours on an oil bath. It waS then poured into a
mixture of crushed ice and brine and extracted with CH2C12.
After washing the organiC extracts with water, and drying
over Na2SO4, the solvent waS removed on the aspirator and
left 1.73 g. oil. No further purification was attempted.
H H H H
H
N ~ ~ N
78 COOBz 79 COOBz
A mixture of crude "enol-mesylate" 7~8 (1.71 g.; 3.4 mm)
and triethylamine (0.48 ml.; 3.4 mm) in CH2C12 (50 ml.)
was refluxed for 5 hours. It was cooled, washed with 10%
HCl and water, dried over Na2SO4 and evaporated on the
aspirator to give 1.35 g. oil. This was purified by chromo-
tography on 75 g. silica gel III eluting with ether/petroleum
ether 2:1. The pure cis-~-lactam was obtained as white
crystals, m.p. 97-98 (MeOH).
Anal. Calc'd. for C22H20N4O4: C, 65.34; H, 4.98;
N, 13.85.
Found: C, 65.36; H, 4.96;
~, 13.97.
- 130 -
H H H H
N3 ~ ~
COOBZ COOBZ
79 80
A mixture of "azido isocephem" 80, (0.81 g.; 2 mm)
and triethylamine (0.56 ml.; 4 mm) in CH2C12 (50 ml.)
was cooled in an ice bath and while being stirred, was
saturated with H2S. The cooling bath was removed and there
was gas evolution. After stirring at room temperature for
1 hour, the solution was evaporated at room temperature
and partitioned between ether and 10% HCl. White crystals
separated and were collected by filtration, washed with
ether and dried to give 1.12 g. white solid, m.p. 120-123
with decomposition. The free base was obtained by sus-
pending the solid in water, alkalizin~ with cold concen-
trated NH40H and extracting with CH2C12. This was washed
with brine, dried over Na2S04 and evaporated on the aspir-
ator.
H 0OCH2CONH H H
n l; ~ ~ ~DO \~
N~ ~ N~
COOBz 81 COOBz
A solution of "amino isocephem" 80 (0. 49 g.; 1.~5
- mmole), phenoxyacetic acid (0.16 g.; l.OS mm) and EEDQ (0.26 g.;
1.05 mm.) in CH2C12 (50 ml.) was stirred at room temperature
~ - 131 -
for 2 hours. It was washed with 1~ NaHCO3 solution, then
with brine, dried over Na2SO4 and evaporated on the aspir-
ator to leave 0.49 g. white solid, m.p. 146-148C. It was
used with no further purification.
00C112CO~1 ~ZOC~2CON~
H2/Pd(OH)2 >
~ 0 0~ ~ --
COO
COOBz 82
81 (BCL-54)
A solution of isocephem compound 81 (0.49 g.; 0.9
mm) in ethyl acetate (75 ml.) was added to a prehydrogenated
sample of 20% Pd(OH)2 on carbon (0.50 g.) in ethyl acetate
(25 ml.). It was then stirred under hydrogen at atmospheric
pressure and after 15 minutes, gas consumption had ceased.
It was filtered through a celite pad, washed well with
ethyl acetate, and the solvent was removed on the aspirator
to leave 0.40 g. of an amorphous solid. This was suspended
in ether and extracted with 2% NaHCO3. The aqueous extract
was acidified with 10% HCl and the white solid collected
by suction filtration, washed with water and dried to give
a white solid, m.p. 160-162 with decomposition. Recrystal-
lized from CHC13/ether, m.p. 162-163 with decomposition.
Anal- Calc'd for C23H22N26 C, 65-39; H~ 5-25;
N, 6.63.
Found: C, 65.28; H, 5.36;
N, 6.56.
- 132 -
A sample of compound 82 prepared above which can be
named 7~-phenoxyacetamido-3-phenethyl-~3-0-2-isocephem-4-
carboxylic acid (also called BC-L54) after solution in water
and dilution with Nutrient Broth was found to exhibit the
following Minimum Inhibitory Concentrations ~M.I.C.) in
mcg./ml. versus the indicated microorganisms as determined
by overnight incubation at 37C. by tube dilution. Cephalexin
was included as a comparison compound.
~ 10
i..
", ,~
,'''`'.
:~
~,
.~
~,,
~ i,~
-- ..
~..
..
_ .
-
-133-
Table 4
M. I . C . in mc~ . /ml .
.. , O~anis7n BC-1,54 Cesha-
1 exin
, .
; D. pneu.~7oniae A9585 .03 .13
; t5% serum*
ctr. pyogene.~ A9604 .a3 .13
t 5Z s er~*
S. aureus Smith t A9537 .06 .25
S . aureus Smith $ A9537 4 . 5
~50% serum
S. aureus BX1633-2 A9606 8
.~. at 10-3 dil 'n
i~ S. aureu2 BXl 633-2 A9606>125 4
: at 10- dil 'n
S. sureus meth.- A1509712~ 32
dl 1 ' n
~, Sal. enteritidis ~ A9531 ~}25 2
, E. coli Juhl ~ A15119 .S 4
~:. coli ~ A9675 >125 8
.;
.~ ~. pneumoniae A9977 >125 2
. K. pneumoniae ~ A 15130 >125 8
. Pr. mirabilis ~ A9900 >125 4
Ps. morganii $ A15153 >lZ5 ~125
Ps. aeruginosa ~ A9~43A ~125 ~125
Ser. r~rcescens ~ A20019 ~125 ~125Ent. cl~cae A4656 ~125 >}25En~. cloacae ~9657 >125 2En~. clcacae A9~59 >125 >~ 75
* 5~Z Nutrien~ 3roth - 457, Antibiotic Asssy Broth
at lC-4 dilution.
- 1 3 4 -
l~i3
:
Example 7
Potassium 7~-Phenoxyacetamido- ~ 3-O-2-isocephem-4-
carboxylate
- 0OCH2CONH H H
`1
~ ~ ~ H
' O
~ .02K
HCO2Et ~ CH2-CO2Et NaOEt > NaOCH=C-CO2~t
NHCHO NHCHO
21
v~ /
,.c,O~
~, k/'i!-C~
. .
~' (EtO)2CHCIH-CO2Et NaHCO3 > (EtO)2CHCH-CO2Et
;~ NH2 HCl NH2
22
.~ ~
' Procedure: A mixture of ethyl N-formyl glycinate (21)
(454 g., 3.46 moles) and ethyl formate (1800 ml.) was
slowly added into a suspension of freshly prepared sodium
ethoxide (3.46 moles, dried in high vacuum at 150C.
for 24 hrs; the sodium ethoxide must be completely free
of ethanol as yields are considerably lowered otherwise)
in 2620 ml. of dry benzene with stirring in an ice bath for
three hours. The suspension was allowed to stand at 4C.
for 18 hours. The solution was carefully decanted and the
solid residue washed several times with benzene. To the
solid was added slowly 4500 ml. of 15% HCl-absolute ethanol.
- 135 -
.~
The solution was stirred at 25C. for 18 hours. The
ethanol was remo~ed by distillation at reduced pressure.
The residue was dissolved in 4.8 liters methanol, then
750 g. of sodium bicarbonate was added at 25C. The
suspension was stirred 18 hours, filtered and the
filtrate evaporated. The residue was taken up in 4
liters of ether, dried over anhydrous sodium sulfate
and evaporated. The oily residue was distilled ~o
give 170 g. (28%) ~,R-diethoxyethylalanate (223,
b.p. 90-94C. (0.1 - 0.13 mm). (Literature b.p.
71/1 mm; Ellis V. Brown, Chemistry of Penicillin
(H. T. Clarke et al.) Princeton Univ. Press. 1949,
p. 473-534).
The NMR and IR spectra of 22 were consistent with
the assigned structure.
~,~-diethoxyethylalanate was also prepared by
the following procedure:
To a suspension of 49.5 g. (0.65 moles) of
sodium ethoxide (Note 1) in 300 ml. benzene was added a
solution of 65.5 g. tO.05 moles) N-formyl ethyl glycinate in
300 ml. ethylformate in a 3 L. flask equipped with a
mechanical stirrer at 0C. over 30 minutes. After stirring
for 1 hour, the solution clarified and was allowed to stand
18 hours at 4~C. A solid separated from the solution. The
supernatant liquid was decanted and tAe residue washed
with 300 ml. benæene.
- 136 -
~i~134~ `
To the solid was added 150 ml. ethanol and 550 ml.
CH2C12 and the suspension was cooled to 0-5~C. in an ice
bath. To the solution a stream of dry HCl gas was added
for 1 hour. The cooling was re ved and the HCl gas bub-
bled in an additional 5.5 hours after which the solution
was allowed to stand at 25C. for 18 hours. The excess
HCl was purged by passing a stream of nitrogen through
the solution for 30 minutes and the solution cooled to
-10C. in a methanol-ice bath. A stream of al~,~nia was
passed through the solution until the pH = 9Ø The
solution was diluted with 500 ml. CH2C12 and the solid
ammonium chloride removed by filtration. The filter cake
was washed with an additional 500 ml. CH2C12. The filtrate
was evaporated to dryness at reduced pressure (bath
temperature <45C.). The residual oil was extracted
with ether (2 x 500 ml.) and the extracts evaporated to
dryness. The residual oil was extracted into petroleum
ether (20-60C) (3 x 300 ml.). The extracts were dried
over Na2SO4, filtered and evaporated to yield 54.6 g.
(~54%). The NMR and IR spectra of this oil were
identical in all respects to those of authentic
22. This oil could be used as such in subsequent steps.
Distillation gave 43.7 g. (42.5%) of pure 22 b.p. 60-75C.
(0.005 millimeter/Hg.).
Note 1. Commercial NaOEt was used. The 30~ excess was
necessary.
~ - 137 -
(EtO)2CH-fH-CO2Et + 0-CH=CH=CHO
NH2
22
~
C~C~
~0
N3CN2COCl ~ OEt
OEt - N ~
N ~ OEt CH2C12 ~ \ OEt
C2Et
CO2Et 24
23
Procedure:
A Preparation of Schiff Base (23). A mix-
~
ture of 95.2 g. (0.46 mole) ~,~-diethoxyalanine ethyl ester
and 60.8 g. (0.46 mole) cinnamaldehyde in 1.5 L. of
methylene chloride was boiled at reflux for 30 minutes.
After this initial reflux period 850 ml. of methylene
chloride were distilled at atmospheric pressure over
1.5 hours. (azeotrope with water)~ The concentrated
solution was dried over anhydrous sodium sulfate (large
excess >100 g.) for 1 hour. The drying agent
- 138 -
was removed by filtration and the solution of 23 evapor-
ated to dryness at reduced pressure and the residue
pumped at ~ 1 millimeter/Hg. pressure for 30 minutes at
40C. The residue was then diluted to 1.3 liters with
dry methylene chloride.
The formation of the Schiff base may be accom-
plished in a number of ways. On a small scale the two
reactants may be mixed in a suitable solvent (benzene,
ether, CH2C12, etc.) in the presence of a drying agent
(Na2SO4, MgSO4). Alternatively the water may be removed
azeotropically with benzene. Inasmuch as the subsequent
reaction is done in methylene chloride the above method
is preferred. The CH2C12 is dried by passing thru an
alumina (Act I) column which removed any alcohol which
may be present as preservative. At the end of the
reaction a small aliquot was evaporated and the NMR
- and IR spectra taken to check for completeness; the yield
is quantitative.
- 139 -
B. Preparation of azidoacetyl chloride.
The azidoacetyl chloride was prepared via a modification
of the method of J. H. Boyer and J. Horner, J. Am.
Chem. Soc., 77, 951 (1955).
To 128 g. (1.354 mole) chloroacetic acid in
300 ml. of water was added 7 ml. 50~ sodium hydroxide
solution (0.0875 mole) and 110 g. (1.69 moles) of
sodium azide. The slurry was contained in a three-
necked 2 liter round-bottom flask fitted with two
efficient condensers and an addition funnel. [THE
REACTION MUST BE DONE IN AN EFFICIENT FUME HOOD! The
original literature preparation used at least one
equivalent of sodium hydroxide whereas we used less than
10 mole %.~ The mixture was layered with 100 ml. ether
and heated on a steam bath for 24 hours. The orange
solution (occasionally colorless) was cooled to 0-5C.
in an ice bath. To the cooled solution was added 300 ml.
of 10~ H2SO4 followed by solid sodium chloride to
saturation. The solution was extracted with ether
(5 x 200 ml.), the extracts dried over sodium sulfate.
The drying agent filtered, and the ether evaporated below
30C. at reduced pressure. The NMR spectrum of the
residual oil indicated it to be a 1/2 hydrate of
azidoacetic acid contaminated with 10% ether. The oil
was used without further purification.
To the oil cooled in an ice bath was added 340 g.
~2.85 moles) thionyl chloride (the addition of the first
- 140 -
.
50 ml. is slow as vigorous gas evolution occurs, the
~ remainder is added quickly). After addition, the
; solution was refluxed 2 hours. The excess thionyl
chloride was distilled at reduced pressure (<50C.,
70 mm). The residue was distilled to yield 93 g.
(57.2~) azidoacetyl chloride, b.p. 38-40 C/12-15 mm
Hg. The distillation must be carried out using a
water bath the temperature of which must never exceed
80C. An explosion occurred in one run where higher
bath temperatures were utilized. The NMR and ~R
spectra are consistent with the assigned structure.
C. ~-lactam formation. The freshly prepared
Schiff base solution (0.46 moles in 1.3 1. methylene
chloride) was cooled to 0-5C. with ice bath. To
this 46.1 g. (0.46 mole) triethylamine was added. A
solution of 56.0 g. (0.46 moles) azidoacetyl chloride
in 500 ml. methylene chloride was added dropwise over
1 hour. The solution was stirred an additional 30 min.,
washed with water, saturated NaCl solution, and dried
over Na2SO4. Evaporation of this solution yielded 187.0 g.
(>98% crude yield) of compound 24 as a reddish oil.
The compound 24 was obtained as a mixture of
diastereoisomers (24a and 24b). Occasionally a by-
product was also obtained when excesses of azido acetyl
chloride were used. This by-product has been identified
as 25.
- 141 -
., ~.
0 /0
H ll
OEt > 3 ¦ r OEt
N ~ OEt ~ N ~ OEt
CO Et
C2Et 2
23 24a
~
0 0
H H ~ ~ J
Et
C2Et
C02~t
24b 25
Compound ~ is thought to arise from further reac-
tion of 24a and/or 24b with the acid chloride. The stereo-
chemistry of the azido and styrryl substitutents of 24a, 24b
and 25 has been shown to be exclusively cls; no trace of trans
component could be detected by NMR. The mixture of compounds
24a and 24b was readily separated from 25 by column chromato-
graphy (Dry-column technique on silica gel (15% H20) using
ether as eluent).
Purification of compounds 24a and 24b ~y chromato-
graphy was not satisfactory as losses occurred. Only
partial separation could be achieved. When the cyclo-
addition was carried out as described formation of 25
- 142 -
~'
1~13~
,
Wa8 mlnimal ( <2 - 5h).
Compound ~ wa~ shown to be a single geometrlc~l
~80mer as indicat~d ~n ~he d~agram abo~e.
oenerslly the compound 24 Wa8 u~ed as such in
aubsequent reactions.
A ~mall sample Or the crude ~-lactam 24 was
chromatographed on sillca gel (deactlvated - 15%
~ater) ~ dry ~olumn technlque u~lng methylene
chlorlde as eluent. Two pure fract~ons (as determlned
by-TLC ~nd NMR~ were obtalned corre~ponding to com-
pounds 24 and 25. The 0119 were analyzed.
Compound 24 (ml~ture of dia3tereolsomer~)
MW S 402.460
Anal. Calc'd ~or C20H26N405. 0.1 C~2C12:
C, 58.50; H, 6.35; N, 13.64.
Found: .C, 58.48; H, 6.48; N, 13.38,
Compound ~
MW = ~56 ~90
Anal. Calc'd For Cl8H20N40~: C, 60.66; H, 5.66;
~, 15,72,
Found : C, 60.78; H~ 5.73;
N, 15.9~.
-143-
~ 3 ~ ~
~' ~
H ~ ¦ Na~H > ~ H
3~OEt ~Et
211 O 2
~o ~
~Et
02CH2~
~Q!~ , ,
A. ~n a 3 llter round bottomed flas~ equlpped wlth
a magnetlc ~tlrrer was dlssolved 119 g. (0.296 moles)
o~ compound 24 ln 1 llter of ethanol. ~o thl~ was
added 100 ml. Or water followed ~y 12~0 ml. of 1%
a~ueous sodlum hydroxlde over a perlod of 1.5 hours.
-144-
1~1.- I L~ ~ ~
The solutlon wa~ malntained at 20 - 25 C. A~ter
addltlon, the ~olutlon was stlrred 1 hour. To the
solutlon was added 10% HCl to pH 3 rollowed by 500
ml. saturated NaCl solutlon. m e aqueou~ phase was
e~tracted by three portlons of CHCl~ (600, 300, ~00
ml.) and the or~anlc layer evaporated. The resldue
~as re-dls~olved ln 500 ml. ether and extracted wlth
three portions (~00, ~00, ~00 ml.) o~ saturated sodium
blcarbonate solutlon. The aqueous layer was acldi~led
to pH 3 wlth 10~ HCl and extracted lnto CHC13 (ln
three portlons, 600, 300 and 300 ml.). The organlc
l~yer wa~ dried over MgS04, ~lltered, and evaporated
to yleld 97 g. (88~ yleld) Or crude acld 26. The IR
and NMR spectra o~ the acld were conslstent wlth the
assl~ned ~tructure.
B. The acid 26 ~192 g.) wa~ dl~solved ln 1 1.
dry C~2C12 with 53.5 ~. (73 ml.) o~ trlethylamlne
and cooled to 0 - 5 C. ln an lc e ba th. To thls wa 8
added benzyl chlororormate (96 g. ) dropwise oYer a
two hour perlod wlth stlrring. Followlng the addltlon
the solutlon wa3 ~tirred at room temperature or 30 mln.
m e ~olutlon wa~ wa~hed w~th water (2 x 2~0 ml.) untll
neutral, with brine solution (100 ml.) and then drled
over M~S04. Evaporation afforded 27 as a dar~ brown
~11. Ihe oll was pa~sed through a column Or granular
ads~rbant magne~ium silicate (Florlsll, 400 g.) wlth
methylene chlorlde to gi~e 234 g. (8~ crude yleld)
*Trade Mark
-145-
I
b
of the desired ester 27. NMR and IR spectra were
compatible with the assigned structure.
Generally the oil was not purified further but
was used as such in subsequent reactions.
The reaction proceeds according to the following
scheme.
RC02H > R~ -O-C-O-CH20 _co2 R-BOCH20-
The IR spectrum of the crude reaction mixture
indicates no mixed anhydride to be present.
The crude product contained the mixture of
desired diastereoisomeric esters, benzyl alcohol, and
a small amount of acid. The column chromatography
removed much of the acid and other impurities. The
benzyl esters are generally not very stable to column
chromatography so purification is usually carried out
at a later step in the sequence.
~ H H
ff H ¦ - CHO
O OEt ~ ~ ~ ~ oEt
C02CH20
C02CH20
27 28
,_
_ ocedure:
A solution of 4.8 g. (10.04 mmoles3 compound 27
in 80 ml. dry methylene chloride was prepared and cooled
-146-
? ,~
to -78C. in an acetone-dry ice bath. To this was
added ozone until a blue color persisted. The ozone
addition was ended and the excess ozone removed by
bubbling dry nitrogen through the solution. To the
solution was added 5 ml. of dimethyl sulfide.
The purpose of the dimethyl sulfide is to
decompose the initially formed ozonide.
~ ~ N CH0
3 ~ ~ + Me2S > ~ ~ 0CHO+DMS0
0 R
The DMS0 thus produced can also react with the ozonide
as shown below
o
/ R ~ H + 0C02H+DMS0.
O~
I
S
The washing with the MaHC03 removes the benzoic acid thus
produced.
~ he solution was allowed to some to room tempera-
ture over 1 hour. The solution was then washed with water
(20 ml.) t saturated NaHC03 (20 ml.), water (10 ml.), brine,
and dried over MgS04. The solution was filtered and
~ - 147
1~134~
evaporated to give 5.0 g. of an oil. The by-product
benzaldehyde was removed by distillation at 0.05 mm. Hg.
and a bath temperature of ~65C. The residual oil
4.0 g. (95%) was analyzed by NMR which indicates 77%
free aldehyde 28.
The desired aldehyde forms a hydrate which
tends to lower the amount of free aldehyde observable
in the NMR spectrum.
H H H H
_ - ~ CHO - - ~
OEt O ~ ~ OEt
C02CH20 C02CH20
28 29
Procedure:
To 3.5 g. (9.0 mmoles) of compound 28 in 30
ml. 95% ethanol at 0-5C. was added 255 mg. (6.0 mmoles)
of sodium borohydride with stirring. After 30 min. at
0-5C. the solution was stirred an additional 30 min.
at 25C. The solution was acidified to about pH 4
with 10% hydrochloric acid and diluted with 40 ml. ice
water. The aqueous layer was extracted with chloroform
- 148 -
(3 x 30 ml.). The combined extracts were washed with
water (2 x lO ml.), brine, dried over MgS04, filtered
and evaporated to yield 3.4 g. crude alcohol 29. The
oil was chromatographed on silica gel (5% water) with
chloroform to yield 3.0 g. pure alcohol 29 (85~). The
IR and NMR spectra were compatible with the assigned
structure.
- 1~9 -
~ .~
~ ~34~
H H H H
OEt > ~ OAc
N ~ OEt ~ N ~
C02CH20 C02CH20
29 30
.~
_ ocedure:
A mixture of 3.2 g. (8.17 mmoles) compound 29,
11 ml. acetic anhydride, and 1.12 g. (8.2 mmoles) zinc
chloride was stirred 18 hours at 25C. The reaction
mixture was evaporated at reduced pressure and the
residue taken up in 50 ml. - methylene chloride - 20
ml. water. The organic phase was separated, washed
with water, brine, dried over MgSO4, filtered and
the filtrate evaporated to yield 3.0 g. of an oil.
The oil was chromatographed on 50 g. silica gel
~deactivated - 5% water) by dry column technique using
chloroform as an eluent. Evaporation of the eluent gave
1.3 g. (41%) of pure 30 as an oil. The IR and NMR spectra
were compatible with the assigned structure.
- 150 -
,~
6~i
H H H H
3 ~/\OAc 3 ~/\OH
OEt H30 ¦ OEt
o N ~5~J CH30H o~ ~N ~J
C02CH20 C02CH20
_ ocedure:
Compound 30, 5. 95 g. (15. 35 mmoles) was refluxed
in 3S ml. CH30H and 35 ml. 10% hydrochloric acid for a
period of 1 hour. The solvent was partially evaporated
at reduced pressure and the aqeuous residue was extracted
with chloroform ( 3 x 30 ml.). The combined extracts were
washed with water (2 x 10 ml.), saturated brine, and dried
over anhydrous magnesium sulfate. The solution was filtered
and evaporated to give 4.6 g. (87% yield) of 31 as an oil.
The NMR and IR spectra of this oil were consistent with the
assigned structure.
H H H H
3~ ~OEt 3~
C02CH20 C02CH20
31 32
Procedure:
A solution of 4.6 g. (13.3 mmoles) compound 31,
1.03 g. (14.0 mmoles) pyrrolidine, and 900 mg. (14.0
mmoles) acetic acid in 50 ml. of benzene was refluxed
- 151 -
18 hours~ The solvent was evaporated at reduced pres-
sure and the residual oil was taken up in 60 ml. of
chloroform. The chloroform solution was washed with
water (15 ml.), brine, and dried over MgSO4. The
drying agent was filtered off and the filtrate
evaporated to dryness to give 3.50 g. (71% yield)
of crystalline enamine 32, m.p. 111.5 - 112.5C.
The NMR and IR spectra were compatible with the
assigned structure.
Anal. Calcd for C18H21N5O4: C, 58.21; H, 5.70;
N, 18.86.
Found: C, 58.23; H, 5.72;
N, 19.10.
OH OSO CH
H H ~ H H 1 2 3
r
N ~ N~J
C02CH2~s C02CH20
32 33
Procedure
-
A solution of 2.44 g. ~6~6 mmolesj compound
~2, 3.9 g. ~33 mmoles) methane sulfonyl chloride and 3.3 g.
(33 mmoles) triethylamine in 50 ml. methylene chloride was
stirred at ambient (25DC.) temperature for 74 hours. The
reaction mixture was washed with water (2 x 10 ml.),
- 152 -
brlne, and drled over Na2S04. The drylng agent w~s
~lltered ofr and the flltrate evaporated to dryne~s.
The oll was ~lltered through a sillca gel column
(deactlvated - 15% water) (16 g.) wlth chloroform to
glve 2.6 g. (90%) of crystalline mesylate ~ , m.p.
116 - 117.5 C. The IR znd MMR spectra were compatlble
~ith the asalgned structures.
H OS02CH3 H H 1 2
C02CH20 C02CH20
33 3~ .
~ ' ~ .
ocedure~
A solutlon of 2.28 g. (5.26 mmoles) compound ~ in
25 ml. o~ acetone and 2~ ml. 10~ hydrochloric acld was
refluxed 15 minutes. The acetone was evaporated at
reduced.pres~ure and the resldue extracted with
chloroform t~ x 30 ~1.). The chloroform layer wa 3
wa~hed with water and evapor~ted to dryness. The
re~ldual oll was dissolved in ether (20 ml.~ and the
solutlon extracted wlth ~aturated sodium blcarbonate
--153-
solutlon (4 x 8 ml.). The bicarbonate was acidifled
to pH 4 wlth 10~ HCl and re-extracted wlth chloroform
~ 0 ml.). The chloroform wa~ washed w1th water,
br~ne and drled over MgS04. The drying agent was
rlltered o~ and the flltrate evaporated to gl~e
1.62 g. (81%) of compound 34. The IR and ~M~ ;
spe~tra of ~4 were compat~ble wlth the a~lgned
structure.
The NMR spectrum o~ ~4 shows two signals for
the benz~l group. Thls may be due to two causes -
hydrogen bonding cau~lng restrlcted rotation or
~eometrlcal l~omerism.
0C~2 ~ 0H2 2 2
-154-
OSO2CH3
~ H I H H
N3 ~ >
N ~ N
C02CH20 C2 CH20
34 35
~ ~
Procedure:
To a suspension of 198 mg (4.70 mmoles) sodium
hydride (55% mineral oil dispersion, washed 3X with
petroleum ether) in 5 ml. dry dimethyl sulfoxide
(DMSO) was added a solution of 1.62 g. (4.27 mmoles)
compound 34 in 5 ml. DMSO over 5 min. with stirring
at 25C. [Gas evolution was observed to cease after
15 - 20 minutes. Prolonged reaction times gave lower
yields of 35. The optimum time was 45-60 minutes.]
After 1 hour, the reaction mixture was poured into
50 ml. 1~ HCl-ice water and was extracted with chloro-
form (4 x 30 ml.). The organic layer was washed with
water (3 x 10 ml.) brine~ and dried over MgSO4.
Filtration and evaporation of the filtrate gave 1.2 q.
of 35 as an oil. Trituration with ether caused
crystallization, 545 mg., m.p. 110, of 35 were
collected. The NMR and IR spectra were compatible
with the assigned structure.
Anal- Calcd- for C14H12N44 C~ 55-99; H~ 4-03;
N, 13.66.
Found: C, 55.23; H, 4.02;
N, 18.91.
- 155 -
H ~ H H H H
- -- o H2~/\o 00CH2Co
N ~ N ~ N ~
C02CH2~C02CH20 C02CH20
36 37
Procedure:
A. Compound 35 (500 mg.; 1.66 mmoles) was
dissolved in 20 ml. of dry ethyl acetate. To this
was added 450 mg. of 10% Pd/C and the solution was
stirred under hydrogen at atmospheric pressure and
room temperature for 30 min. The solution was
filtered through diatomaceous earth ("Celite"*)
and the filter cake washed thoroughly with methyl-
ene chloride. Evaporation of the filtrate yielded
500 mg. of crude amine 36. The NMR and IR spectra
of the compound were compatible with the assigned
structure. Compound 36 was used in the subsequent
step without further purification. [On standing some
decomposition was noted. The amine should be used
as soon as possible after preparation.]
B. Compound 36 (500 mg.) was dissolved in
10 ml. of dry methylene chloride and cooled to 0-5C.
*Trademark
- ~56 -
ln an lce bath. To this was added 280 mg. (2.8
mmoles) o~ trlethylamlne and 346 mg. ~2.0 mmoles)
Or phenoxyacetyl chloride wa~ added 810wly. After
stlrrln~ ror 1 hour at 0-5~ C. the solutlon was
washed wlth water (2 ~ 10 ml.) and drled over
Na2S04. After evaporatlon the residual oll
wa3 taken up in 50 ml. of ether and filtered.
The flltrate wa 9 evaporated and triturated wlth
ether-petroleum ether (1:1). The so~ld thu~
obtained was collected by ~iltration to yield
570 mg. crude amlde 37. The amlde was chromato-
graphed on a silica gel column (undeactlvatedJ
(~5 g.) with benzene-acetone (lnl~ially ln a
ratio 50:1, gradually changed to l:l - 2% more
acetone every 25 ml.). The de~ired amlde ~7 wa~
obtained pure, 195 mg.
Th~ NMR and IR spectra were ccmpatible wlth
tne as~lgned ~tructure.
H H
00CK2~0 ~ ~ ~ ~O~I~C0~ ~ 0
~2C~0 G02X
37 3
-157-
l~
~`
.
: :
J~ ~P~cedure
Compound 37 (210 mg.; 0.514 mmoles) w2s dissolved
ln 40 ml. ethyl acetate ~nd 1 ml. gl~cial acetlc ~cld
was ad~ed. Usln~ ~10 mg. (~ 2C%) palladium hydroxide
on charc~al as catalyst, the solut~on w2s hydro~enated
3t 58 psi for 50 minute~.
l~e re2ction mlxture was iltered through "Cellte"
(tw~ce) an~ the catalyst wa~ washed thorou~hl~- with
chloroform (20 ml.). T~e ~lltrate was evapo~at2d to
~ryne q and then evaporated ~ times with benzene ln
order tc strip of~ the acetlc acld. A very viscous
. oll was obtained which ~as washed wlth 10 ml. benzene.
The residual oil wa~ scratched wlth 10 ml. ether.
The solld 38 whlch formed w2~ collect d by fil~ratlon
to ~leld 115 mg. (70.5~). U,V. ~max. 268, . 95'~9
No sharp m.p. was observed. (D.p. ~2~2 C.)
Anal. 521cd. ror C}~14N206 1/2 hydrate:
C, 55.o6; H, 4.62; N, 8.56. Found: C, 5~.19;
E, 4.70; N, g.00.
H H H H
0QC~CON~ ~ ~ ~ 00C~2Co~
- 0~ 0~
G ~ CC
38 39
_ _~
~s~cedure:
To a solutlon of 30 mg. compound ~ ln 3 ml.
meth~ obutyl ketone was added one or two drops
o~ 50% solutlon o~ pota3siu~ 2-ethylhexanoate ln
butanol. A whlte crystalline materlal separated
almo~t lmmedlately whlch was collected by flltratlon,
washed wlth methyl lsobutyl ketone and dried over
P205 ~or 48 hour~ under hlgh vacuum to yleld 18 mg.
39 (53.5~). U.~. ~max. 263,~ 5528.
No sharp m.p. or d.p. could be observed.
Anal- Calcd- for Cl~Hl3N2o6K-l/2 H2o
C, 49.31; ~, 3.82; N, 7.67. Found: C, 49.35;
H, ~.94; ~, ~.21.
A sample of compound ~9 prepared above which can
be named pota~slum 7 ~-phenoxya;e~amido- ~ -0-2-isocephem-4-
carboxylate (called BC-I2) after solutlon ln water and
dilutlon wlth Nutrlent ~roth was found to exhibit the
~ollowing Minimum Inhlbltory Concentratlons (M.I.C.) ln
mcg./ml. versu~ the lndlcated mlcroorgani~ms as determlned
b~ overnlght lncubatlon at 37 C. ~y Tube Dllutlon. One
old, orally absorbed cephalosporln (cephalexln) wa3
~ncluded.
.
-159-
~able 5
M.I.C. ln mc~./ml.
Or~anism ~ CeDha
l~xln
D. pneumonlae A9585 .6 .6
~5% serum*
Str. Pyoeenes A9604 . .6 .3
~5% serum~ --
S. aureus Smlth~ A9537 1.3 1.3
S. aureus Smith~ A9537 1 2.5
~50% seru~
S. aureus BX1633-2 A4606 2.5 4
at 10-3 dil'n
S. aureu~ BX1633-2 A9606> 125 8
at 10- di}'n
Sal enterltldis~ A953116 4
E. coll Juhl~ A1511963 8
E coli~ A9675~125 16
R. pneumonlae~ Aq97732 8
K. pneumonlaet A15130>125 16
Pr. mlrabllls~ A9900. 63 4
Pr. morganllt A15153> 125 ~ 1~5
Ps. aeruglnosa+ Ag843A> 125 >125
Ser. marcescen~ A20019> 125 ~125
S.rasietu~ amtetlO-3 A15og7~ 125 ~2
dll ~n
~50% Nutrlent Broth - 45% Antiblotlc As~ay Broth
-4
at 10 dllutlon
-160-
Exam~le 8
/0
H r/ 1 0 ~ CXO
2. (C~32S N ~
C2Et C02Et
24 40
_ v
. ~roce~u~e:
A solution o~ ~3.0 g. (0.107 mole) o~ c~pound 24
~as prepared by the method of Exzmple 7) in 700 ml, of dry
methylene chloride was cooled eo -78C. in an acetone dry
: ice bath and a st-eam of ozone passed through fQr 2 hours.
At the e~d of this time the solu~ion turned b~uish-green
.
.t Ond the ozone was replaced by a stream of dry nitrogen.
~''b When the exce~s ozone ha~ be~rl purged (2 S ind~ cated
by the disappearance o~ the blue color) 30 ml. of
." .:
dlmethyl sul~ide was ad~ed . The solution was a llowed
to cor.e to ~oom ~emperature (~ 25 C.) o~er 1 nour.
me sclution was ev2pora,,ed to d~ s;, ând the ?esid~e
~edis~olved in 800 ml. C~I2Cl~. 'rhe solu~.io~ 2S was:~e~
wl~,h wa tzr, br~ ne and d~ e~ over M~SCL~ a pora t ion
~ the solu,,lon ~ave an ot ly -~esidue whic~ was distill~d
for 18 hours at ?~o - 50 G. and 0.1 ~r~ic~, to, emove
ben~alceh~de~ yielded 40.5 g. o~ ~0 ac an oil.
~e h7~ spectrum indicated 75~; free aldehyde. ~.
crude aldenyde W25 used in the ~e~;t ste~ w~hou~
f'urther p ~r iS`ica' io-. .
H H H H
CHO ~ OH
~N~<OEtt ,~ N\~<oEtt
C2Et C2Et
Procedure:
A solution of 40.3 g. of compound 40 in 250
ml. ethanol -12.5 ml. H2O was prepared and cooled to
0-5C. in an ice bath. To this was added 1.56 g.
(0.041 moles) sodium borohydride and the solution
was stirred for 30 min. at 0-5C. To the solution
was added 10~ hydrochloric acid to pH 4. The
reaction mixture was evaporated to dryness at
reduced pressure below 35C. To the residue was
added 200 ml. of brine and the solution was extracted
with chloroform (3 x 200 ml.). The extracts were
dried over Na2SO4, filtered and evaporated to yield
37.0 g. of crude alcohol 41. The crude alcohol was
filtered through a column of activity III alumina
(550 g.) using chloroform as an eluent to yield
27.0 g. of reasonably pure alcohol 41 (>90%). The
IR and NMR spectra of the oil were compatible with the
assigned structure.
The overall yield from compound 24 was 76.5%.
It has been found that the ozonolysis and reduction pro-
cedure can be combined by carrying out the oxidation in
ethanol and reducing the ozonide in situ with NaBH4. This
gives an ~3-85~ yield of equimolar amounts of 41 and benzyl
- 162 -
3~
alcohol. A small sample of the alcohol was purified by
column chromatography on alumina (Act II).
MW - 330.351.
nal. Calcd- for C13 22 4 6 C,
H, 6.71; N, 16.96.
Found: C, 47.26;
H, 6.85; N, 17.15.
H H H H
N3 ~ OEt > 3 ~
N ~ OEt o ~ _ OEt
C2Et C2Et
41 42
Procedures:
To a solution of 6.20 g. (18.8 mmole) of alcohol
41 in 100 ml. of dry methylene chloride was slowly added
a solution of 4.0 g. (28.2 mmole, 3.54 ml.) boron tri-
fluoride etherate in 20 ml. dry methylene chloride over
15 min. at 0-5~C. The cooling bath was removed and
stirring was continued for 18 hours. The reaction mixture
was filtered through a column of activity III alumina
(40 g.). The column was washed with 300 ml. chloroform.
The eluted fractions were evaporated to dryness to yield
6.0 g. of 42 as an oil which by TLC analysis was at least
90% pure. The NMR and IR spectra were compatible with the
assigned structure [In Constrast to the methyl ester
dimethyl acetal analog of 41 only one isomer was
- 163 -
4~
obtained on cyclization_ Careful chromatography of 42
gave a 76% yield of one pure isomer with the stereo-
chemistry indicated in the figure. A small sample was
rechromatographed for analysis.
Anal. Calcd. for CllH16H4O5
H, 5.67; N, 19.71. Found: C, 46.54;
H, 5.85; N, 19.34.
H H H H
N ~ O N3 ~ o
N ~ OEt ~ N ~ OEt
C02Et C02H
42
Procedure:
To a solution of 12.2 g. (43 mmoles) of com-
pound 4~2 in 180 ml. ethanol was added 175 ml. 1% sodium
hydroxide over a period o$ 10 min. at ~25~C.
The solution was stirred an additional 20 minutes.
The ethanol was evaporated at reduced pressure and
the alkaline solution was extracted with ether
(2 x 200 ml.). The organic layer was discarded
and the aqueous solution acidified to pH 3-4
with 10% hydrochloric acid. The solution was
extracted with chloroform (2 x 100 ml.), the organic
layer washed with water (50 ml.), brine (50 ml.),
and dried over MgSO4. Evaporation gave 7.25 g. (66%)
of acid 43. Trituration with ether and filtration
gave pure acid 43, m.p. 114-115~C. The NMR and IR
spectra were compatible with the assigned structure.
- 164
~ ~ b
Anal. Calcd. for CgH12N4O5: C, 42.19; H, 4.72;
N, 21.87.
Found: C, 42.18; H, 4.83;
N, 22.01.
H H H H
r ~ H2N ~0
~ N ~ OEt ~ N ~ OEt
C2Et C2Et
42 44
ProcedureO
A mixture of 760 mg. (2.8 mmole) of compound
42, 925 mg. ammonium chloride (17.1 mmoles) and 620 mg.
(17.1 mm.) zinc powdex in 35 ml. ethanol was stirred
at 25C. for 3 hours. The reaction mixture was
filtered through "Celite" and the filtrate evaporated
to dryness. The residue was taken up in chloroform
and filtered through 30 g~ of Alumina (Act III).
Evaporation of the eluent yielded 578 mg. of crude
amine 44. The amine was redissolved in 15 ml.
chloroform and extracted into 10% ~Cl (2 x 3 ml.~.
The aqueous layer was neu~ralized with sodium
bicarbonate and extracted into chloroform. The
extracts were dried over Na2SO4, filtered, and
extracted into chloroform. The extracts were
- 165 -
dried over Na2SO4, filtered, and evaporated to yield
360 mg. of an oil which crystallized on standing. The
amine 44 was recrystallized from ether, m.p. 98.5 -
99C. The IR and NMR spectra were compatible with
the assigned structure.
MM = 258.
Anal- Calcd- for CllHl8N2O5: C, 51-15:
H, 7.03; N, 10.85.
Found: C, 51.16; H, 7.01;
N, 11.03.
H H H H
H2N ~\ o 00CH2CONH~/\O
~ N ~ OEt 0OCH2CO2H ~ ~OEt
CO2Et ~ Et C-O2Et
N
2Et
(EEDQ)
Procedure:
A solution of 400 mg. (1.55 mmole) of compound
44, 410 mg. (1.64 mmole) EEDQ and 250 (1. 69 mmole) phen-
oxyacetic acid in 20 ml. dry methylene chloride was
stirred at 25C. for a period of 1. 5 hours. The
reaction mixture was filtered through a column of
alumina (activity III 8 g.) and the eluent evaporated
to dryness. The resultant solid was washed with
- 166 -
dried over Na2S04, filtered, and evaporated to yield
360 mg. of an oil which crystallized on standing. The
amine 44 was recrystallized from ether, m.p. 98.5 -
99C. The IR and NMR spectra were compatible with
the assigned structure.
MW = 258.
11 18 2 5 ' 5;
H, 7.03; N, 10.85.
Found: C, 51.16;
H, 7.01; N, 11.03.
H H H H
00CH CON ~ O
0CH2C2H 2 1 l l
OEt ~ > O ~ OEt
C02Et~ N OEt C2Et
C2Et
(EEDQ) 45
P edure:
A solution of 400 mg. (1.55 mmole3 of compound
44, 410 mg. (1.64 mmole) EEDQ and 250 (1.69 mmole) phen-
oxyacetic acid in 20 ml. dry methylene chloride was
stirred at 25DC. for a period of 1.5 hours. The
reaction mixture was filtered through a columr. of
alumina (activity III 8g.) and the eluent evaporated
to dryness. The resultant solid was washed with
- 167 -
ether and collected by filtration to yield 554 mg.
(90~), m.p. 162-164. Recrystallization from
chloroform-ether gave analytically pure amide 45,
m.p. 166.5 - 167.5C. The IR and NMR spectra
were compatible with the assigned structure.
MW = 392.417
Anal Calcd- for C19~24~27
H, 6.16; N, 7.14.
Found: C, 57.93;
H, 6.23; N, 7. 34.
H H H H
_ /\ -- ~ /\
0OCH2CONH~ I > 0OCH2CONH~ O
O ~ ~ OEt O ~ ~ OEt
C2Et C02H
46
,v ,
Procedure:
A solution of 392 mg. (1 mmole) compound
45 in 13 ml. warm methanol was added to 12 ml. 1% NaOH
at 25C. with stirring over 10 min. After 1 hour
the methanol was evaporated and the alkaline solution
was extracted with chloroform ~2 x 20 ml.). The
aqueous solution was acidified to pH~4 with 10%
- 168 -
HCl and extracted with chloroform (2 x 15 ml.). The
extracts were washed with water, dried over Na2SO4,
filtered, and evaporated to give 200 mg. (55%) of a
white solid. Recrystallization from methanol-ether
gave pure acid 46, m.p. 150-151.5C. The IR and
NMR spectra were compatible with the assigned
structures.
MW = 364.363
Anal. Calcd. for C17H20N27 0-5 CH3
H, 5.83; N, 7.37.
Found: C, 55.08;
H, 5.53; N, 7.48.
H H H H
~ ~ 1) PC15 ~OEt
C02CH
C02H
43 47
,_
Procedure:
To a solution of 6.25 g. (25.6 mmoles) of
compound 43 in 100 ml. of ether was added 5.35 g. (25.6
mmoles) phosphorous pentachloride. The suspension was re-
fluxed for 15 min. after which the clear solution was de-
canted and evaporated to dryness. The residual oil was
taken up in 50 ml. benzene and evaporated to dryness at
- ~69 -
f~
reduced pressure. Thls procedure was repeated three
tlmes to remove phosphorous oxychlorlde. The re31dual
oll was then pumped in hl&h vacuum (0.05 mm Hg) at 30 C.
~or 1 hour. m e NMR and IR spectra were compatible
ror the deslred acid chlorlde.
The acid chloride was taken up in 20 ml. dry - -~
methylçne chloride and was added to a mlxture of
2.7 g. ~26 mmole) benzyl alcohol and 3.2 g. trl -
ethylamlne in 50 ml. dry methylene chlorlde at 25 C.
over a period o~ lO minutes. The solutlon was stirred
ror l hour, washed wlth water (2 x 20 ml.), brlne and
~lltered through 20 g. of "Florl~ll". The eluent was
treated wlth charcoal (Norlte~, drled over MgS04,
rlltered and evaporated to glve ? 4 g. (83.5%) of
crude benzyl ester 47. Trlturatlon with benzene-
petroleum ether caused crystalllzatlon. The ~olld
~a9 recrystallized ~rom benzene-petroleum ether to
yleld pure 47, m.p. 79 - 79.5 C. The IR and NMR
8pectra were compatlble with the asslgned structure.
MW - 346.352
Ansl. Calcd. for C16H18N405: C, 55.49; H, 5.24;
~, 16.18.
Found: C, 5~.81; H, 5.3~;
~, 16,~o,
-170-
H H H
r
N~r ~/~ OAc
LOEt
Eo2c~2~ c~2{~20
3 -.
.
procedure:
A mlxture of 6.5 g. (18.8 mmole) compound 47,
50 ml. acetlc anhydride, and 5.1 g. (37.6 mm) zinc
chlorlde was stlrred at 0-5~ C. for ~0 mln. then
at 25 C. for 18 hours. The reactlon mlxture was
e~aporated to dryness at reduced pressure and the
resldue taken up ln 200 ml. methylene chlorlde 50 ml.
water. The organic phase wa~s separated, washed wlth
water, ~rlne, and drled over MgS04. Flltration and
evaporation Or the ~lltrate gave an olly re~idue
whlch was chromatographed on 60 g. alumina (Activlty
III) wlth chloroform to yield 5.~5 g. (7~%) of
compound 30 ldentlcal ln all respects with that
obtained earller.
-171-
},~ L~
'',:
H H K H
: ~ ~ OAc i~ ~ OAc
L OEt ~ 2 ~ qEt
C~C~2~ ~2C~.
~,j ~0 / 48
.,
~ ~ L
~OCE2CO ~ Ac
2 ~ 0
~j ~Q!~!~
~ To 325 mg. (o.84 mmole) of.co~ound 30 ln 5 ml.
.~ d-y methanol was added 325 m~. zinc powder and 300
r~ E
m~. ammonium chloride at 0-~ C. The suspen~ion
was stirred for 1 hour, ~iltered, 2nd the ~ rate
evapor2ted to ~leld ~12 crude amine 48. .The IR
.~
.~ spect~um in~lc2ted com?lete reduc~lon o~ the ~zldo
:;- functlon.
.
The srllde amine 48 was treate with 1~0 m~.
(0.92 m~o~e) phenox-~ac_tlc aci~ ~nd 2~0 m~. (0.92
~m~le) E~DQ ln 10 ml, methylen~ c:nlor~de at 25 C.
~or 1 ho~-. rne ~oluvlon wa~ washed w~th lQg ~1
~5 ml.), water (5 ml.), brine, d~led over Na2S04,
iltered, a~d the flltrate evapo.ated. The crude
a~lde 49 W2S c;.rom2tc~raphed on 2 7~in2 (Actlvi~
I~I) uqir.~ chlorofcrm as eiuon~ 'o 51~Je 230 m~.
?ure a~l~e '~ ar.d ~n addt~ion21 100 mO~ ~ ~3C~
p~re am.lde. ~ne ~ an~ 1?~ spect~a were cs.,.~n2tible
~tn ~;e ~ r.ed s'ructures.
H H H
2 ~ ~ Et ~ 2 : ~ ~ QEt
02CH20' C02CH~
- ~
~Qçedure:
A solutlon of ilO mg. (0.222 mmole) of 49 ln
4 ml. methanol and 2 ml. 10~ hydrochloric acid wa~
reflu~ed for 1 hourJ diluted to 20 ml. wlth water
and extracted into chloroform. The extract~ were
drled over Na2S04, flltered, and e~aporated to
yield 74 mg. (75~ of the de~lred slcohol 50. The
NMR and IR spectra were compatlble wlth the
as31gned ~tructure.
H H ~ ~ OH
-- _
0OCH2~0 ~ > ~OCH2CO~
co2CH2¢~ C02CH20
50 51
~5~ e:
A ~o~utlon of` 14Q mg. (0.31 ;T~nole~ com~ound 50
l~C5 mg. 2cetic acidJ and 140 mg., pyrrolidi.ne ln 10
--173--
~13~
I
ml. ~enzene was bolled at re~lu~ for 16 hours. The
solution wa~ evapor~ted to dryn_ss, taken up ln
chicro~orm ~20 ml.), washed with water (5 ml . ),
10~ HCl (5 ~1.), saturate~ NaHC~3 solutlon (5 ml.),
brine ~5 ml.), dried over Na2~04, flltered, and
e~aporated to yleld 157 m~. crude enamlde 51 (100~.
m e I~ and ~R spectra were com2atlble wlth the
QQ~lgned structuL~e.
H ~ OH _ ~S2cx3
~OCHco~J3 00c~2c~
. C2C~2~ ~2CH20
. 5
,P~ o.
.` To a solution o~ 157 mg. (0.31 mmole) o~ c-ude 51
and 0.5 ml. pyrid~ne ln 5 ml. methy}ene chlorlde was
added 170 ~g. of meth2ne ~ulfonyl chlor~e at 0-5 C.
The solutlqn was stirred at 25 C. for 48 ho~ s, evaporated
at reduced pres~ure~ taken up ln chlorofo~m, washed wlth
. water and drled o~er Na2S04. The solution was L lltered
ard passed t~rou~h a ~nort column o~ alu~na (5 g,
-174-
.` ~$~3'~
Activlty III) with chloroform a3 eluent. Evaporatlon
o~ the eluted fraction gave 170 mg. ( ~ 90%~ crude
me~ylate 52. The NMR ~nd IR spectra of ~2 were
compatlb~e with the a~signed structure.
_ 2 3 H H OS02CH~
CX2C0 ~ ~ 00CH2CO ~ ~H
C2G~20 C02CH20
52 53
Procedure:
A solutlon of 200 mg. compound 52 i~ ~ ml. acetone
and 1.5 ml. 10% HCl wa~ refluxed for 1~ min., dlIuted
to 50 ml. wlth water and extracted lnto chloroform
(~ x 25 ml.). The extracts were evaporated and the
resldue redlssolved lnto chloroform which was ex-
tracted with sodlum blcarbonate solution. The aqueous
layer was acldified to pH - 4 wlth 10% HCl and extracted
lnto chloroform (3 x 25 ml.). The extracts were dried
over Na2S04, ~iltered, and evaporated to yield 180
mg. crude enol ~. The N~L~ and IR ~pectra we~e
compatlble wlth the a~slgned ~tr~lcture.
-175-
~ $ ~
H H ISO2CH~ H H
0'0cH2cD~ ~ 0OCH2CC~
C02t~H20 C02CH2~ ,
53 37
v~ ~
oçedure:
Compound 53 (70 mg.) wa~ treated for 1 ho~lr
~ith 5.6 mg. (60~ mlneral oil disperslon - washed
with petroleum-ether) o~ sodium hydrlde in 2 ml.
DMS0 at 25 C. The ~olution was poured into 20 ml.
lce cold 1~ HCl and extracted lnto chloroform
(3 x 10 ml.). The solution was washed with water
(2 x 10 ml.), brine (10 ml . ), dried over Na2S04,
~11tered, and evaporated to glve 60 mg. of crude
37 ldentical in all respects to that obtained via
a~glatlon Or ,6.
-176-
Ex~mple 9
Benz~l 7B-Azldo-~3-0-2-isocephem-4-carboxyl~te
OS02C~3
H H I H H
J CH2C1
C02CH2f~ co2CH2
- 34 35
A 801ut~0n of 682 mg. ~0.00174 moles) of 34 and 195 mg,
(0.00192 moles) TEA in 10 ml. C~2C12 was r~fluxed for 5
hours . The ~olution was washed with waterg brine, dried
over Na2S04, filtered and evaporated to yield an oil.
Tr~turation with ether and flltration gave 393 mg. (75.57.)
pure 3S. An additional 21.0 mg. were recovered from the
mother l~quors. Co~pound 35 prepared in ~his m~nner was
identical ln all respects with that obtained earlier
(~.p., lR and ~
xample 10
*~
~3 ~ ~ MeS02Cl, E~3N N3 -- OS~M2
OET ~ N ~ ~t
~ E~ 8~ C0
To B ~olutian o 9.6 g~ (29 ~mol~ ~f com?ound 83
-1.77-
~note 1) and 9.0 ml. of t~iethylam~ne in 96 ~1. c' ~thylene
chlo~de at 0-5~ was added d.opwise a solution o, 4.8 g.
. (42 ~ole) of methanesulfonyl chlo.ide in 24 ml. of
methylene chloride. After standing at 2~ for on~ hou~,
~ the solution was washed w~th e~ual volumes of wa~er and
.~ . 10% hyd.ochloric acid. Evaporation o~ the solvent gave a
yell~w oil which was chromatog~a~hed on 18~ g. of alumina
:; (grsde ITI). E}ution w1th chlorofo.m gave ehe partially
:pur~fied product 8~ as a yellow o~l, 5.56 g. (4770 yield),
.~ The IR and the NMR were consistent with the ~ssigned
~ s~ructu~e. (Note 2)
:~ Note 1: The purity of the st~rting materîai (compound 83)
~as not known with certainty but it may have
been less than 70% pure.
Note 2: The N~R in~icated the product wa~ or about 707a
.~ purity.
:
N H H H H
, ~~~S02Me ~ ~ S02M~
~ ~ct HOAc, AczO ~ ~ ~t
: ~4 8S
, C2E~ C02E~
.
A mi~ture of 4.~ g. tl2 mmole) of c~mpound 84 , }O ml.
of acetic anhydride, 10 mi. of ace~ic acid and 1.75 g.
(13 m~ole) or 7ir_ chloride was stirred at 25 for 17
hours, then evapcrated to a tar. A mechylene cnloride
~olutio-. of .he tar (50 ml.~ was washed wi~h e~ual ~oiu;:les
-- 178 --
.
of water, 5% sod~um bicarbonate and dilute sodium chloride.
The methylene chloride solution was filtered through 15 g.
of alumina (grade II~) and evaporated to give an o~l.
Trituration of the o~l w~th ether gave pure compound 85
as a colorless powder, 1.88 g. (45% yield~. The IR and
NMR were consistent with the assigned structure.
H H
N3 oSo2Me lzNaoH~THF ~ Na enolate
,~ ~ 86
I ~Et
C2Et
H H
= =
N ~
87 C02Et
To a solution of l.~i g. (5~99 mmole) of compound 85
in 20 ml. of tetrahydrofuran was added 20.0 ml. of 0.25M
sodium hydroxlde (NstP 1) solution dr~pwise over 10 minutes.
The resulting solution was~concentrated to 20 ml. on the
rot~ry evaparator at 30. The concentrate was washed with
chloroforsn (3 x 10 m~. ) (Note 2~ . The aqueous layer was
~vapo~ted tQ dryness under high vacuum, The resulting
residue ~sodium enolate 86 ) was stirred with 7.5 ml. ~f
dlmethyl ~ulfox~de ~or one hour. Water (30 ml.j and
-179~
saturated sodium chloride (40 ml,) folluwed by a few drops
of 107. hydrochloric acid were added to the dimethylsulfoxide
~olutlon, The resul ing mixture was extracted w~th chloro-
form (3 x 40 ml,) and the combined chloroform layers we~e
w~shed with water and ev~porated to give the crude product,
Pure compound 87 was obtained by recrystallization from
benzene/cyclohexane, then chloroform, as colorless crystals,
0.39 g, (33% yield), The IR and NMR were consistent with
the a~s~gned ctructure.
Note 1: Other concentrations of base and ~th~r solvents
(acetone, dimethoxyethane, acetonitrile) were
tried but the conditions described h~re gave
better yields.
Note 2: The chloroform extract gave a yell~w oil, 0,58 g.
contain~ng 65Z compound 85 and 35% of an unident~-
fie~ byproduct.
Example 11
Benzyl 7~-Azid~ 3-0-2-isocephem-4-carboxylate
H H
M3 ~--`oS02Me ~, ~3Na~ll, IIIF ~ N 1~
~N~ 2. I)MSO ~ J
C02C~2Ph
8B 89 C02CH2Ph
~
To a ~olution of 26~ mg. (0.64 mmole) of compsund 88
-18~-
in 2.5 ml. of tetrahydrofuran was added 2.55 ml, of 0.25 M
80dium hydroxide solution dropwise over 10 minutes. The
solution was concentrated to 2 ml. on the rotary evaporator.
The concentrate was washed with chloroform (2 x 2 ml.),
then evaporated to dryness under high vacuum. The residue
wa~ stirred with one ml~ of dimethyl sul~oxide for one hour.
Water (1 ml.), saturated sodium chloride (l ml.) 2nd one
drop of 10% hydrochloric acid were ~dded. Th~ mixture
was extracted with chloroform (3 x 2 ml.) and the combined
chlorofor~ layers were washed with water and evaporated
to give crude compound 89 as a yellow solid~ 103 mg. (54%
yield)~ The IR and NM~ were consistent with the as~ioned
structure. The NMR indic~ted t~e ?roduct was about 75%
pure (i.e. true yield of 40%).
Ex2mple 12
7~Phenoxyacetamido-3-carbomethoxymethylene- ~ 0-2-
i~ocephem-4-car~oxylic acid
~OCH CONH- ~
N ~ CH2Co2cH3
93 C02H
-181-
3~
H2CONH H H H
d~ ~ ~IOCH2CON~ CHzC02H
so C02CH2B ~' G02CH2
Appsrstus consisting of 8 2S0 ml. ehree necked flas~
equipped with a low temperature therometer, a gas inle~,
protected with a gas bubbler (parrafin oil) and magnetic
stirring, was dried by heating with a bunsen torch while
pa8s~ng dry nitxogen through the apparatus. It was all~wed
to cool to 25C. before b~ing opened, under nitrogen flow,
to introduce the reagents.
A solution of benzyl 7~ -raminophenoxyacetoyl~-3-
methyl-~3-0-2-i~socephem-4-car~oxylate 90 (2.11 g.; 5 mmole)
in 100 ml, of THFl was cooled to -70 un~er a slow nitrogen
seresm. A solution of 1.66 M butyl lithium2 (6.34 ml.;
10.5 mmole) was slowly added keeping the reaction tempera-
ture at -70~C. A slow stream of dry carbon dioxide gas
~8 then introduced into the reaction mixture, the cooling
th was removed, and the carbon dioxide intr~duction con-
t$nued un ~1 ehe reaction temperature reached 25~
The reaction mixture was poured into 200 ml. of 10~.
hydrochloric aci~, satura~ed with sodium chloride, an~
ext~acted three times with d~ethylether ~150 ml. portions).
-182-
The comb~ned extracts were washed three times with brin~,
dr~ed (anhydrous sodium sulfate) and e~aporated in vacuo
to give 2.09 g. of a yellow gum. Th~s gum was partitioned
between diethylether and 10% sodium bicarbonate solution
three times. The bicarbonate solu~ions were then washed
w~th die~hylether (tw~ce; 50 ml. portions) and with
methylene chloride (twice; 50 ml. portions). The bicar-
bonate solution was then acidified to pH2 with concen-
- trated hydrochloric acid and ex~racted three times with
methylene chloride (100 ml. portions). The methylene
chloride extracts were washed twice with brine, dried
(a~hydrous sotium sulfate), and evaporated in vacuo to
glve 0.31 g. of 3 colorless gum. This gum was used as-
such ~n the next step,
1. The ~HF used was reagent grade whioh had been further
dried by passing over an alumina column.
2. Foote Mineral C~mpany
H
~CH2CQ~, 0C~2~~
I CH~C02H ,1
91 C2C~Z0 u~ ~ `CH2co2cH3
A solu~ion of diazomethane in diethyletherl was slowly
added to 8 solutlon of ~en2yl 7-B-[aminophenoxyacetoyl~-3-
c~rboxymethylene^~3-0-2-~socephem-4~carboxylate 91 (0.88 ~,)
~n 100 ml. of diethylether, until a permanent yellow color
-183-
L~ ~
(exces~ diazome~hane) was produced. The reaceion mixture
was then stirred at roo~ temperature for 10 minutes. The
reaction was acidified with 10/. hydrochloric acid and
extracted twice with 100 ml. portions of diethylether.
The extrac~ was washed with 10% sodlum bicarbonate solutlon
(tw~ce; 75 ml. por~ions), with brine (once; 100 ml.), dried
(~nhydrous sodi~m sulfate), and evaporated in vacuo to give
0.72 g. of activ~ty III silica and then dry column chroma-
tographed over 36 g. of activity III silica gel. Elution
with chloroform gave a fract~on containing 240 mg. of
methyl ester 92 NMR and IR spectra are in agr~ement with
~
~he assigned struc~ure. Th~s material wa3 used as such
in the next step.
1. Prepared from nitrosomethylurea according ~:o A.I. Vogel,
'~ractical Organic Chemistr~", 3rd Edn., L~ngm~ns
Green Co., London, 1958, p. 969.
H H H
~OC~CO~ ~ 0OC~2CONH~
N ~ CH2~02~H3
9~ G02CH2~ 93 ~ CH2C02CH3
~ ~- CO~H
A mixture o~ benzyl 7~ -~aminophenoxyacetoyl~-3-carbo-
methylene~~ -0-2~1socephem-4-carboxylate 92~147 mgO), 10/~
Pd-C, (100 ~g.)7 25 mlO of ethanol (USP) and 15 ml. of THF
was hydrogen~ted in a Parr hydrogenator at 17 psig for
1 hour. The cst~lyst was filtered off and the filtrate
ev~porated to dryness in vacuo to give 87 mg. of a white
fo~m.
The potassium salt of acid 93 was prèpared by d~ssolv~ng
the foam in a sm~ll amount of methylisobutylketone and
sdding 8 saturated solution of potassium 2-e~hylhexanoate
in butanal. The resultant precipitate was filtered off
~nd washed with methylisobutylketone and then diethylether.
M.P. 139-145C. with decomposition (cor.). Spectrsl data
conf~rm structure assignment.
An~l.Calc~d.for ClgHl7KN20g-1/2H20: Cs 49.42; H, 4,l5;
~, 6.40.
Found: C, 4~.05; H, 4.07;
N, 6.29,
A sample of compound 93 prepared above (called BC-L33)
~fter solution in water and dilution with Nutrient Broth
was found to exhibit the following Minimum Inhibitory
Concentr~t~ons (M.I.C.) in mcg.¦ml. versus the indicated
microorganisms as determined by overnight incubation st
37aC. by tu~e d~ lution. Cephalexin was included as a
comparison compound.
-185-
Table 6
M.I.C. in mc~./ml.
Or~nism BC-L33 Cepha-
lexin
D. pneumoniae A9585 .06 .16
~5% serum* -
Str. pyogenes A9604 .06 .16
~5% serum*
S. aureu~ Smi~h ~ A9S37 .25 .6
S. aureus Smi~h ~ A9537 1 1.3
~50% serum
S. aureu3 BX1633-2 A9606 16 2
at 10 dil 'n
S. aureu~ BX1633-2 A9606>125 4
at lQ dil'n
S. aureus meth.- A15097~125 32
resis~; at 10-3
dil, n
Sal. enteritidis ~ A9531~ l -
E. coli Juhl ~ A15119125 4
E. coli ~ A9675>125 16
K. pne~moniae ~ A9977 63 2
X. pneumoniae ~ A15130>125 8
Pr. mirabilis ~ A9900 32 2
Pr. morganii ~ A15153>125 >125
Ps . aer~gincsa ~ A9843A~125 >125
Ser. marcescens ~ A2QOl9>125 >125
En~ cloacae A9656>125 ~125
Ent. cloacae A9S57>125 2
Ent. cloacae A96Sg>12S ~125
* 50% Nutrient Broth - 457~ Antibiotic Assay Broth
~t 10~4 dilutionO
-186-
Example 13
Separation of Diastereomers of
d-cH-coN~
2 ~ 0
. C02H
The N-protected benzyl ester (1.3 g,) of the formuls
H-CONH ~ O
'NH l
22~ ~ ~ ~CH3
co2CH20
was placed on a sili~a gel column (340 ~. of sllica gel -
15% water) and eluted with ether/petroleum ether (30-60
boillng) 70:30 ratio. Initial fractions consisted entirely
of one ~somer designated "isomer A", intermedlate fractions
were mixtures of isomer A and the other isomer designated
"~somer B", and later fract1Ons (212 mg.) contained 75-80%
is~mer B and 20-25% isomer R.
A sclution of the isomer B concentrate (l50 mg.) in
10 ml. of ethyl acetate plus 10 ml. of 95% et~lanol was
treated with exactly one equivalent (OJ26 ml,) of lN HCl.
To th~s solution was ~dded 150 mg. of 30% palladium-on-
distomaceous earth and the mixture was hydrogenated at
ro~m temperature and a~mospheric pressure unt~l uptake o~
hydrogen ceased. The c.ealyst was removed by filtration
and the solvent evaporated to give 7B-(a-amino-l-phenyl-
acetamido)-3-methyl-f~3-0-2-isocephem-4-car~oxylic acid
(75-B0% isomer B, 20-25% isGmer A) with 1/4 to I mole
ethanol and 1 to 2 mole~ H20 of crystsllization per mole -
of acid. Any attempts at purification led to degradation.
H20
The product had U.V. ~Max 270 ( - 78S0). The ~ isomer
w~8 found to be the biologically active isomer.
M.I.C. data for the above product (called BC-L45
~8 shown in Table 7.
-1~8-
Table 7
M.I.C. in mc~./ml.
Or~anism BC-L45 Cepha-
lexin
D. pneumoniae A9585 <.25 .13
~5X seru~*
Str. pyogenes A9604 <.25 .13
t5~ serum*
S. aureus Smith ~ A9537 1 .25
S. aureus Smith ~ A9537 8
t50% serum
S. aureus BX1633-2 A9606 8
~t 10-3 dil'n
S. ~ureus BX1633-2 A9606 63 4
at 10-2 dil 'n
S. aureus meth.- A15097 63 63
res~st; at 10-3
dil'n
Sal. enteritidis ~ A9531 4 2 ..
E. coli Juhl ~ A15119 4 8
E. col~ ~ A9675 32 32
K. pneumoniae ~ A9977 4 4
K. pneumoniae ~ A15130 8 16
P~. mirabilis ~ A99~0 8 4
Pr. morganii ~ A15153 63 ~125
Ps. aeruginosa ~ A98~-3A~125 ~125
Ser. marcescens ~ A20Ql9~12S ~ 25
Ent. cloacae A9656 125 >125
Fnt. cloacae Ag657 4 4
Ent. cloacae A9659 125 ~125
* 50% Nutrient Broth - 45% Antibi~tic As~ay Broth
at lQ-4 dilution.
-189-
Mouse Blood Levels of BC-L45 and cephalexin after
oral administration of 100 mg./kg. body weight are shown
below:
Blood Levels ~g/ml)
0.5 1 2 3.5
BC-~45 19.4 15~7 7.3 2.9
Cephalex~n 42.4 23.7 9.8 ~.0
Example 14
7~-(D-a-aminophenylacetamido)-~3-0-2-isocephem-4-
carboxylic aci~
H Hj:H-CONH - b
. NH2-HCl~
C02H
Benzyl 7~-azido-~3-0-2-isocephem-4-carboxylate
(300,3 mg., 1 mmole) and 300 mg. 10% Pd/C in 40 ml. ethyl
scet~te wa~ shaken under H2 for 4S minutes a~ 60 psi~ The
suspension was fil~ered ~hrough celite and evaporsted to
--19 0~
dryn~ss. The IR 6pectrum of residue indica~ed complete
reduction cf azido function to benzyl 7~-~mino-~3-0-Z-
I~ocephem-4-carboxylate.
The above-mentioned benzyl 7-amlno intermedi~te was
diJsolved in 25 ml. CH2C12 and treated wlth 285 mg.
(~ mmo~e) N-carbobenzoxy-D-phenyl glycine snd 247.3 mg.
(1 mmn~e) EEDQ for 2 hours. The solution was washed
~ith 10% HCl ~2 x 30 ml.), fiaturseed ~queous NaHC03 and
~r~ne. The crude amide W88 chromstogrsphed on s~lica
gel and eluted with CH2C12. The IR and NMR spectra
~ndica~ed form~t~on of the N-protected compound of the --
fo~mul~
~-~H-CONH
HNC02CH20 ~ ~
co2CH2~
A su~penslon of the above N-protected compound
~308.5 mg., 0.570 mmole) ~nd 900 mg. 207~ Pd (OH)21C ~n
mixture of 40 ml. ethyl ~cetate and 1 ml. ~cetic ac~d
W~8 sha'~en under H2 at 60 p8i for 1 hour. The suspens~on
.w~8 filtere~ through celite (filter eflke~ washed wi~h
200 ~1. CR2C12) and evaporated to y~eld ~he free c~rboxyllc
~e~d of the sbove N-protected ester.
EtOP 264, ~ 5203
Max
~ n~l. C~lc'd~ for C22H~lN307~1l2H20: ~, 58-9 ;
~, 9~37.
Found~ C, 55.12; H, 4.95;
N, 8~950
--191--
A suspension of 305 mg. (0.695 mmole) of tl~e above
free acid, 58 mg. anhydrous NaHC03 and 300 mg. 30% Pd/
dlatomaceous earth in 25 ml. H2O-15 ml. dloxane (pH 7-7.5)
W~8 agitated under H2at 60 psi for 45 min~te~. The
~uspension was filtered ~filter cake washéd with 50 ml.
M~BK and 10 ml. water) and filtrate was stirred for 20
minute~ (pH 7.0). The organic layer was separated and
the p~ of the aqueous layer adjusted to 3.7S with HCl.
The solvent was pumped under high vacuum ~freeze-dried)
for 21.5 hour~ to give 200 mg. of the title produs~ as
a pale yellow powder.
U V ~ EtOH - 261, looo.
Max
A ~ample of the t~tle product (called BC-L6) ~fter
~olution in water and dilution with Nutrient Broth was
found to exhibit the following Minimum Inhibitory
Concentrations (M.I.C.) in mcg.lml. versus the indicated
microorg~nlsms as determined by overnigh~ incuba~ion at
37~C. by ~u~e dilution. Cephalexin W2~ included a~
~ompar~son compound.
--lg2--
1~4
T2ble 8
M. L . C . .n mc /~l .
Or~anism BC-L~ C~Dha
lexin
D. pneumonlae A9585 16 .3
_C7. serum*
Ser. pyogenes A9604 16 .3
-5% serum*
S. auseus Smith - A~537 32 i.3
S. aureus Smith - A9537 250 5
~5C)% sPrum
S. aureus 8X1633-2 Ag606 125 4
at 10-3 dil'n
S. aureus BX1633-2 A9606 500 8
at 10-2 dil'n
S. sure~s meth.- A1~097>50~ 32
sesist; at 10-3
dil'n
Ssl. enteriti~i~ - A9531 ~2 4
E. col~ 3uhl - A14119125 8 -
E. coli - A9675 250 16
K. pneu~oniae - A9977 63 4
K. pneumoniae - A15130125 16
Pr. mirabilis - A9900 125 4
Pr. morganii - A151S3~500 ~125
Ps; aeruglnosa - A9843A~500 >125
Ser. marcescens - A20Q19~500 ~125
Ent. cloacae A9656
Ent. cloacae Ag657 - -
Ent. cloacae A9659 - -
-
* 5G~ ~utrient Broth - 45Z Anti~iotic Assay B~oth
- at 10-4 dilution.
-1 93-
Example 15
7~-(2-AminomethylphenylacetamidO~-3-methyl-~3-o-2
isocephem-4-carboxylic acid
To a suspension of 1.2 g. (0.038 mole) of potassium 2-(1-
carbomethoxypropen-2-ylaminomethyl~phenylacetate in 23 ml. of
~,, tetrahydrofuran was added 3 drops of dimet~ylbenzylamine. The
mixture was cooled in a dry ice bath to -40 and 520 mg. (0.038
mole) of isobutyl chloroformate was added all at once. The mix-
ture was stirred for 5 minutes and added to a cooled ~3) solution
of 500 mg. of 7-amino-3-methyl- ~3-0-2-isocephem-4-carboxylic acid
and 0.71 ml. of N-methylmorpholine in 13 ml. of water. The solu-
tion was stirred in an ice-bath for 1 hour at 0, then concentrated
hydrochloric acid was added dropwise to pH 5.2. The tetrahydrofuran
,
was removed at 30 (15 mm) and the aqueous solution was layered
with ethyl acetate. The mixture was stirred at 25 for 1 hour and
the crystals were collected, washed with water and dried over
.~,
P205 to constant weight to give 85 mg; mp >150 slow decomposition.
The NMR and IR spectra were consistent for the structure.
Anal. Calc'd for C17~19N35H2
N, 11.56.
Found: C, 56.00; H, 5.68;
; N, 11.32.
Example 16
7~-(~-Benzovlureido~henylacetamidoJ-3-methyl- ~3-o-2-
socephem-4-carboxylic acid
972 mg. (0. oa3 moles) of benzyl 7~-amino-3-methyl- ~3~
0-2-isocephem-4-carboxylate hydrochloride was partially
dissolved in 40 ml. of dry methylene chloride and 302 mg.
-194-
(0.003 moles) of N-methylmorpoline. To this was added 892 mg.
¦ (0.003 moles) of ~-benzoylureidophenylacetic acid and 760 mg.
(O.003 moles) of EEDQ. The slurry was stirred for 30 minutes
at room temperature. Not all went in solution and 12 ml. of
N,N-dimethylformamide was added. A cloudy solution resulted
which turned clear after stirring for 30 minutes. The yellow
solution was stirred for 2 1/2 hours and was then concentrated
to an oil, which was redissolved in 80 ml. of ethyl acetate
and extracted with 80 ml. of 5~ aqueous sodium bicarbonate and
80 ml. of 5% hydrochloric acid. The ethyl acetate phase was
dried over magnesium sulfate, filtered and concentrated to
dryness. The resulting foam was triturated with ether and the
resulting tan solid was remoYed by filtration and dried in vacuo.
Wt = 700 mg. Infrared spectrum and NMR spectrum indicated
~'~ the solid to be benzyl 7~ -benzoylureidophenylacetamido)-3-
methyl-~ -0-2-isocephem-4-carboxylate. This was dissolved
in 95 ml. of 100~ ethanol and 5 ml. of water at 39. 700 mg.
of 30~ palladium on Celite was added. It was reduced at
50 lbs./sq. inch in a Parr hydrogenation apparatus for 30
minutes. The catalyst was removed by filtration through
Celite and it was washed with 100 ml. of 100% ethanol. The
combined filtrates were concentrated to an oil which was
solidified by slurrying it in ether. A tan solid resulted.
¦ It was removed by filtration and dried in high vacuum.
Wt = 250 mg. Infrared spectrum and NMR spectrum were con-
sistent with the desired material.
Anal- Calc'd- C24H22N47~4H2 C,
N, 10.20.
Found: C, 52.45i H, 4.26;
N, 10.22.
I
I -195_
- `
Fxa~.~le i7
7B - (2 .6-D~methox~be~z2~Jdo~-3-methvl-~3-0-2-
Isoceohem-4-ca box~lic a~d
.
729 ~g. (0.002~5 moles) of benzyl 7-amino-3-methyl~
0-2-isocephem-4-carboxyLate hydrochloride was dissolved ~n
15 ml. of acetonitrile and 453 mg. ~0.0045 moles) o. N-methyl-
morpholine. To th~s was added 420 mg. (0.00225 moles) of
2,6-dimethoxybenzoyl chlor~de. The yell~w solution was
~tirred for 2 hours at room ~emp~rature. A .hin layer
chr~m~togram was taken at th~t point and it ~ad one major
spot at Rf 0.6 indicating prod~ct. The reaction mixture
was concent.ated to dryness, taken ~p in ethyl acetate
and extrac.ed with 3Q ml. of 577 aqueous sodium bicarbonate
snd 30 ml. of 5% hydrochlorlc acid. The ethyl~cetate phase
was dried over magnesium sulfate, f~ltered and concent~ated
~o a yellaw foam. It was solidi ied with ether, filtered
~nd dried in high vacuum for ~5 hours. A t~n solid resllted,
wt 500 mg. Infrared s?ectrum and NM~ specerllm indicated
it to be the desired benzyl 7~-(2,6-dimethoxybonza~ido)-3-
methyl-~3-0-2-isocephem-4-c~.boxyla-e. ~his was dissolved
in 100 mL. of 100% ethanol at 40. A ~OZ solution resulted.
To this was added 500 mg. of 3C70 palladiu~ on ~elite. I~
w~s reduced at 50 1DS.fS~ inch in a Parr hydsogena~on
apparat~s for 40 ~inutes. rhe reaction mix~ure waS heated
to 40 and the catalyst was r~oved by ~ ration th.ou~r.
Cel~te. I~ wa~ washed ~ice with 1~0 m1, of 100% ethanol
-196~
r~
! 2~d ~he cc~b~ned ~il.rates we~e concen.~~ted .Q ~ g~eyish
~oi~d, which was washed w~ th e~her, fi~tered and ds ed
in vacu~, wt ~ 350 mg. In~ra~ed spect~~n and N~ s?ectr~mt
were cons~stent w~th the desired ma.erial.
Anal. t:alc'd. for C17HlgN207~i20: C, 53.85; H, 5.27,
N, 7.38.
: Found: C, 54.77; H, 5.15;
R, 7.1~.
xamPle 18
c~ rdrox~henvlacetamido~-3-met~vl-~3-~-2-
,
iso~e~hem-4-carbox~lic acid
_ _ .
; Benzyl 7~-am~no-3-~ethyl-~3-0-2-isocephem-4-carbcxy-
la~e hydrocnloride (972 mg., 0,003 moles) was disso'ved
in 20 ml. of dry methylene chloride ~nd 302 mg (0.003
moles) or N-methylmorpholine. To this was added 536 mg.
(0.003 ~oles) of D-anhyd~o-o-carboxy~ndelic acid. The
;.~
~ellow solution W2S stirred fcr 2 hours at roo~ tem~era-
t~re. Then the reaction mixture was extracted with 20 ml.
of 57O a~ueous sodium ~icarbonate and ~0 ml. of 5% hydro-
chloric ac-~, The methylene chicride ~hase was dried ove~
m~gnesi~ sulf~te, filtered and eoncent~at~d t~ an cii.
It w2s t~~turated wit;n e~her. A yellow foam resulted,
wt ,- 550 mg~ ~.. ra-ed spect_~ and ~ spect~u~ ir~àic2t~d
this t~ be desired benzyl 7B-~D~a-hyd.ox-~?~enylaceta;.~ido)^
3-~ethyl-~3-0-2-isoceph~-4-carboxylGto. T~is was
-197-
dissolved i~ 100 ~ f lOG~/~ et~anol and 550 mg. of 30%
pslladium on Celite was aaded. It was reduced at 5G lbs.
sq. inch in a Parr hydrogenation apparatus for 30 minutes.
The cata~yst was removed by iltr2tion through Ce~ite and
was washed twice with 100 ml. of 100% ethanol. ~he
com~ined filtrates were concenerated to a ~reyish sol~d,
~h~ch was washed with ether, filtered and dried in vacuo,
wt . 420 ~g. ~nfrared spectr~m and N~ spectrum were
cons~stent w~th the desired material.
Anal. Calc'd. for C~6~16N25'C2HSOH C, 57-06;
5.69; N, 7.41.
Found: C, 57.06,
~, 5.15; N, 6.93.
,' .
Exam~le 19
~lacetimidovl~2minoacetamido1-3-methvl-~3-
. ,
- 0-2-isoceohem-4-carboxylic acid
_ Method 1:
Ben~yl 73-amino-3-~ethyl-~ -0-2-isocephe~-4-car~oxyLate
hydrochloride-~243 mg., 0.00075 moles) was dissolved in lO ~1.
of dry m~thyl~ne chloride and 75 mg. (Q.OOQ75 moles) or
~-me~hylmorpholine. To this uas added 170 mg. (O.OC075 ~oles)
~f 3-~enzyl-1,2,4-oxadiazole-5-one-4-acPtic acid and l9G ~g.
¦ (0.0~075 moles) of EE3Q, It was s~irred for 2 houIs 2.
! ro~ te~erat~re and then concent_ated to an orange^ors~
~ foam. It was taken up ~n ~0 ml. o. ethyl acetate and
ex'r2cted with 20 ml. of 5% aquecus sodium bicarbonate and
20 ml. of 5% hydrochloric scid. The ethyl acetate phase
was dried over magnesium sulfate, filtered and concentr~ted
to a browr. oil~ wt = 100 mg. In~r~red s2ect~u~ and N~
.
. spectrum ~ndicated the desired benzyl 7B-(3-benzyl-1,2,4-
. oxadi~zole-5-one-4-acetam~do)-3-methyl-~3-0-2-isocephem-4-
carboxylate.
Metho~ 2:
3-Benzyl-1,2,4-oxadiazole-5-one-4-acetic acid (1.0 g.,
. 0.9~427 moles) was slurried in 12.5 ml. of dry methylene~?~
:~. chlor~de and hydrogen chloride gas was bub~led into the
~ reaction mix~ure for 2 min~tes with cooling. The insoluble
,
m~terial was filtered off and 1.15 g. (0.00553 moles) of
phosphorus pentachloride was aoded to the filtrate in small
portions. All went in solution. It was.stirred for lS
hours at roo~ temperature. The reaction mixture was con-
centrated to dryness and the crystalline resid~e was
triturated with cyclohexa~e, fi~tered and dried in high-
vacuum for 30 minutes. Infr~re~ spectru~ indicated this to
be des~re~ 30benzyl-1,2,4-oxadi~zole-5-one-4-acetyl chloriae.
Tn ehe meanti~e, 24~ mg. (~.00075 moles) o~ benzyl 7B-amino-
3-methyl-~3-0-2-isocephem-4-c~r~oxylate hydrochloride was
dissolved in 10 ml, of dry methylene chloride and 151 mg.
(0~0015 moles) of N-methylmorpholine. To this was added
188 mg. (0,00075 moles~ of 3-~enzyl-1,2,4-oxadiazole-5-one-
4-soety~ chloride. The sLightly yellow solution was stlrred
for 2 hours at room temperflture. Then it was extracted
with 10 ml. of 5% sodium bicarbonate. 10 ml. of 5% hydro-
chlor~c acid and 10 ml. sa~urated sodi~m chloride solution.
The methylene chloride phase was dried over magnesium
sulfsteg filtered and concentrated to a yellow foam,
wt _ 130 mg. Infrared spectrum and NMR spectrum indicated
th~8 to be desired benzyl 7~-t3-benzyl-1,2,4-oxadiazole-5-
one-4-acetam~do)-3-methyl~3-0-2-isocephem-4-carboxylate.
Benzyl 7B-(3-benzyl-1,2,4-oxadiazole-5-one-4-acetamido)-
3-m~thyl- A3-0-2-isocephem-4-carboxylate (200 mg.) was
d~ssolved in 100 ml_ of 100% ethanol and 10 ml. of water
at 40, To this was added 200 mg. of 30% palladium on
Celite, It was hydrogenated in a Psrr hydrogenation
apparatus at 30 lbs./sq. ~nch for 40 minutes. The catalyst
was removed by filtration through Cel~te and was washed
thoroughly with 100 ml, of 100% ethanol. The combined
filtrates were concentrated to a brown oil, which was
601idified with ether, filtered and dried in high vacuum.
A brownish solid resulted, wt = 100 mg. Infrared spectrum
~nd NMR ~pectrum were cnnsistent with the desired mater~al.
Anal, Calc'd. for C18H20N4os~H2o: C, S5.60; H, 5.70;
N~ 14~38.
Found: C, 55.45; H, 5.63;
N, 14.18~
-200~
fi~
Example 20
7~-Valeramido-3-methyl-~3-0-2-isocephem-4-carboxyIic acid
r Benzyl 7~-amino-3-methyl-~3-0-2-isocephem-4-carboxylate
hydrochloride (1.21 g., 0.00375 moles~ was dissolved in 25 ml.
of dry methylene chloride and 375 mg. (0.00375 moles) of
N-methylmorpholine. To this was added 380 mg. (0.00375 moles)
of valeric acid and 950 mg. (0.00375 moles) of EEDQ. The
slightly yellow solution was stirred for 2 hours at room
temperature. Then the reaction mixture was washed with 50 ml.
of 5% aqueous sodium bicarbonate and 50 ml. of 5~ hydrochloric
acid. The methylene chloride phase was dried over magnesium
sulfate, filtered and concentrated to a yellow oil, which was
.,
washed with ether and dried in high vacuum. A yellow oil
resulted, wt = 6~2 mg. Infrared spectrum and NMR spectrum
indicated this to be the desired benzyl 7~-valeramido-3-methyl-
~-0-2-isocephem-4-carboxylate. I'his was dissolved in 100 ml.
of 100% ethanol and 600 mg. of 30% palladium on Celite was
'~ added. This was reduced at 40 Ibs./sq. inch in a Parr hydro-
~;~ genation apparatus for 35 minutes. The catalyst was removed
~, 20 by filtration through Celite and washed thoroughly with 100 ml.
,
of 100% ethanol. The combined filtrates were concentrated to
a brown oil, which was solidified by washing with ether. A
tan solid resulted. It was removed by filtration and dried
in vacuo for 15 hours, wt = 319 mg. Infrared spectrum and
NMR spectrum were consistent with the desired material.
n 1. Cal~ ~. o C13 18 2 5
Found C, 55.35, H, 6.06i N, 9.07.
-201-
~xample 21
C~;H50CH2NHCONH
~0
O ,. ~ - -
C02H , - .-
A mlxture of benzyl 7B-amino-3-methyl-~3-~-2-isocephem-
4-c~rboxylate (1.44 g.; 5 mmole) and phenoxyacetylazidel
(1~0 g.; 5.5 mmole) in benzene (100 ml.) was refluxed for
24 hours. After being kept at room temperature for 3 days,
some white crys~als separated and were collected by suction
filtrat1on; 0.30 g. white solid m.p. l9S-196 with decompo-
s~t~on was obtsined. The filtrate was washed with 1070
HCl, water and brine and then dried (Na2S04~ and evaporated
to g~ve 1.73 g. of a brown oil. Spectral data were in
~ccorda~ce with the structure
0OC~2NHCONH
~fo
CC~CH2~1
1. Jo~eph Weinstoc~, J. Org. Chem. 26, 3511(1961).
A ~olution of the above isocephem compound (1.73 g.;
4.0 mm~le) in absolute alcQhol (~5 ~1.) and tetrahydrofuran
(10 ml~) was added to 107. Pd on C (1.7 g.) and stirred under
hydrogen ~t fl~mospheric pressure for 2 hours, The solu~ion
-202-
4~ ~
~as filtered from the catalyst through celite and evapor^
ated to give 1.03 g. oil. This was partitioned between
ether and saturated NaHC03. The aqueous phase was separ-
ated, scitified with cold 1070 HCl, and extracted with
CH2C12. The CH2C12 extract was washed with wa~er, and
br~ne, dried (Na2S04) snd evaporated to give 0.20 g.
brown semi-solid. This was ~rystall~zed in benzene~
petroleum ether (30-60) and gave a light yellow shiny
solid identified by spectral analysis as the compound of
r the formula
0'0CH2NHCONH
~0
CH3
C02H
M.P. 177-182 with decomposition.
Anal Calc'd. for C16H17N306-1/4 H20: C, 54.62; H, 5.01;
N, 11.94.
Found: C, 54.59; H, 4.96;
N, 11.46.
M.I.C. data for the a~ove product (called (BC-~24) i~
3hown in Table 9.
-203-
Exa~le 22
73~ Yl2ceta~do-3-methyl-~3-0-2-~soceD;~em-~-
ca-boxvl c acid
,e~c~2co~
~ ~ CH3
A mix~re af benzy'L 7~-amino-3-methyl-~3-0-2-isocephem-
4-ctr~oxylate (2.1 g.; 7.3 ~ole), phenylacetic 2cid (1.0 g.;
7.3 mmole) and EEDQ (1.8 g.; 7.3 mmole) in 50 ml. CH2C12
was st~rred ae room ~Pmperature for 2 hours, tben washed
6uccessively wieh lZ Na~C031 lOZ ~Cl and brine. It was
~r~ed (~a2S04) and e~aparated to give 2.9S g. of a thick
syrup identified as benzyl 7~-phenylace~amido-3-methyl~
0-2-~socephem-4-carboxylate. This ester was ~sed as such
wi~h no furi-her purlfication.
- A mixtur~ o the abcve benzyl ester ~0.50 g.; 1.2
mmole) and 1070 Pd on C (0,50 g.) in T~ (29 ml,~ was hydro-
genated at atmosphe~ic 2ressure 2nd after 10 DtnUteS~
upta~e or hydrogen was complete. ~ was filte ed (washed
we~l with CH2C12) and evapo~ated to ~ive 0.29 2 of a
sol~d. This was recrystalli~ed fr~m acetone/e~her to
give a w~iee solid, m.p, lg7-1~8~ with decomposi~i~n,
I which was ideneified by }R and NMR as the ~itle produc~,
~ ~r.al Calc'd. for Cl6H16~25-1-5~Q C~ 5j-91; ~ 5-57;I N, 7.15.
~ound: C, 55.83; .~, S.~5;
~, 7.~7,
C. dc~a for ~;~e ~bove product (called ~C-L30
~h~wn in T~b~Q 9 ~
. Example 23
7B-(2-Thienylacetamido)-3-methyl- ~3-0-2-isocephem-
4-carboxYlic acid
I~H2CONH~f o
H3
COOH
Benzyl 7~-az~do-3-methyl- ~3-0-2-isocephem-4-c~rboxy-
l~te ~314 mg.; 1 mmole) in 50 ml. of absolute ethanol was
hydrogenated at 40 psi of hydrogen in the presence of
palladium chloride (100 mg.) fox 1 hour. The palladium
black was filtered off and the solvent was removed on a
~lash evaporator leaving a crude hydrochloride salt of
7~-amino-3-methyl-~ -0-2-isocephem-4-carboxylic acid
~234 mg.).
This c~ude hyc~rochloride salt was dissolved in 5 ml.
o water and cooled to ~C. in ice bath. Sodium bicarbon-
~te (500 mg.; 6 mmole) was added followed by 2-thienyl
~cetyl chloride (~20 mg.; 2 mmole~ in 2 ml. of acetone.
The mixture was stirred fcr 1 hour and then extracted
tw~ce with diethylether (10 ml. portions). The aqueous
layer was acidified with hydrochloric acid (aqueous lO~o)
and extracted three t~mes with chloroform (10 ml. portions),
The combined chloroform extract~ were concentrated to a
re8~du~1 oil on an evapor~tor~ A ~olid was obtained upon
-205-
3 L~
trituration with diethyl ether and was recrystallized from
ethanol to give 160 mg. (50%) of the title product; m.p.
213C. (corrected).
U.V. ~EtOH = 270; ~ = 9187
max
Anal- Calc'd. for C14~14N25S C, 52-17;
H, 4.38; N, 8.69; S, 9.95.
Found: C, 51.89;
H, 4.59; N, 8.61; S, 9.78.
M.I.C. data for the above product (called BC-L55)
is shown in Table 9.
- 206
~ 3
Example 24
_-[a-carboxy-~-phenylacetamido]-3-methyl- ~ -0-
2-isocephem-4-carbox~lic acid
0CHCONH
\ /\
C2
0
C02H
0 2 2 0 2 H, H + ~ ~CH2CO2CH20
A solution of phenyl acetic acid (27.2 g.),
benzyl alcohol (21.6 g.) and p-toluenesulfonic acid ~380
mg.) in 100 ml. of toluene was heated under reflux under a
Dean-Stark trap until the theoretical (3.6 ml.) quantity
of water had been collected. On cooling, the solution was
washed with dilute NaHCO3 and saturated NaCl and solvent
was removed ln vacuo. The resulting oil was distilled
at 125-129 (0.4 torr~l to give pure benzyl phenylacetate,
37.7 g. (83% yield).
0CH2CO2CH 0 1. LiICA 0cHco2H
2 2. CO2 CO2CH2~
A solution of 20.8 ml. OL 2.4 M n-butyl lithium
in hexane was added to a solution of i-propylcyclohexyl-
amine 17O 06 g. ) in 35 ml. of tetrahydrofllran at -78.
~0 Af ter 10 minutes, a solution Gf phenylacetic acid benzyl
- 2.~7 -
ester (11.3 g.) in 55 ml. of tetrahydrofuran was added
over 10 minutes. After 5 minutes, carbon dioxide was
bubbled into the solution until the yellow color faded.
After warming to 0, dilute sodium carbonate and ether
were added until all the solid returned to solution.
The aqueous layer was separated and the organic layer
extracted with more dilute sodium carbonate. The combined
aqueous layers were washed with ether, cooled to 0 and
acidified with cold 3N hydrochloric acid. The aqueous
was extracted with ether (2 x 100 ml) and the ether
washed with saturated sodium chloride, dried (sodium
sulfate) and evaporated in vacuo to give the desired
acid as an oil, 7.8 g., 58~ yield. The acid has been
reported in the literature: Chem. Abs. 63, 13269 g (1965).
2 ~
\~ O Ç~icHco2H
¦ + I EEDQ
N ~ \CH3 CO2CH20
co2cH2s~
(A) (B)
0CH-CONH
CO 2 CEI 2 0\~
_ N ~ ~ ~ ~CH3
C02CH2ç~
(C)
A solution of one millimole each o~ A, B and
- 208 -
L~;;~ '~
EEDQ in 8 ml. of methylene chloride was maintained at
2~ for 16 hours. The resulting solution was washed with
2~ sodium bicarbonate (8 ml.), 10~ hydrochloric acid (2 x
8 ml.) and saturated sodium chloride (8 ml.), then dried
(sodium sulfate) and absorbed onto 2 g. of grade III
silica gel.
The crude product, absorbed onto silica gel,
was washed with methylene chloride (10 ml.), then extracted
from the silica gel with ethyl acetate (100 ml.). The
extracts were absorbed onto 1.7 g. of silica gel and
placed on an 11 g. column of silica gel (grade III). ~lu-
tion with ether/hexane 75:25 gave pure (C) as the major
fraction (30~ yield). Recrystallization from ether/methylene
chloride gave material with m.p. 152-157 (with decomposi-
tion).
Anal. Calc'd. for C31H28N27 C, 68.88; H, 5.22;
N, 5.18.
Found: C, 68.50; H, 5.38;
N, 5.19.
~CH~Co~H \ / \
CO2 ~ r i _ _2 ~
/ ~ ~ CH3
( C ) C2 CH2,0
~-fH-CONH ~
CO2
O ~ ~ CH
(D) COOH
To a solution of (C) (200 mg.) in ln ml. of
ethanol
- 209 -
plu~ 10 ~1. of ethyl acetate was added 100 mg. of 30%
palladium on diatomaceous earth. rhe resulting mixture
was hydrogenated at atmospheric pressure and 24 until
upta~e of hydrogen ceased. The catalyst was removed by
filtration and the solvent evaporated to give the title
product (D) in quantitative yield. Attempts to crystallize
the crude prcduct led to loss of purity.
- U.V ~ MeoH 269 ( ~ 880~) -
~nax
Anal Calc'd. for C17H16N27~C2H6 l/2H20: C~ 5 -
H, 5,38; N, 6.74.
Found: C, 54.90;
H, 5.28; N, 6.91.
M.I,C, data for the above product (called BC-L48) is
shown in Tsble 9, :~
~21~-
e `
Example 25
7~-(o-Hydroxyphenylacetamido)-3-methyl- ~ 3-0-2-
isocephem-4-carboxylic acid
OH
CH2CONH ~
N ~\ CH 3
C02H
The acylation procedure Of Example 24 was re-
peated with the acylating acid used therein replaced by an
equimolar weight of o-hydroxyphenylacetic aCia. The crude
acylation product, absorbed onto silica gel, was placed
on a column of silica gel (grade III, 8 g.). Elution with
ether gave, as the major fraction, benzyl 7~ (o-hydroxy-
phenylacetamido)-3-methyl- ~ 3-0-2-isocephem-4-carboxylate
in 26.5% yield. The benzyl ester Was hydrogenated as in
Example 24 tQ give the title product.
MeOH
U.V. ~ 274 (~ = 7200).
max
Anal. Calc ' d- for C~ 6N2 6 / 2
H, 4.94; N, 8.32~
Found: C, 56.92;
H~ 5.03; N, 8.33.
M~I.C. data for the above product (called BC-L49)
is shown in Table 9.
E~cample 2 6
7~-~Cyanoacetamido~-3-methyl- A3-o-2-isoce~?hem-4
_- carbox~ic ac~ d
N~CCH2CO~I ' ' ~,
,,: ~ ~
. ~ ~ N~H3
. C02H
The acylation procedure of Example 24 was repe~ted
~ltb the acylating acid used therein repl2ced by an equ~-
molar weight of cyanoacetic acid. The crude a~ylation
product, sbsorbed onto silica gel, W3S placed on a col~
- o 8ilica gel (grade III, 3.5 g.) and eluted wi~h e~her,
methylene chloride and ethyl.acetate. ~he methyl~ne
chlorlde and ethyl acetate fractions were com~ined and
.,., ~.;
triturated with chlorofGrm se~eral ti~es to give benzyl
- ~ 73-(cyanoacetamido)3-methyl-~3-0-2-isocephem-4-
r
.: . c~rboxylate in 31% yield. The benzyl este~ was hyd~
~,.
~se~ted as ~n Example 24 to give the ~itle product.
. P~
U~V. ~ ~69 ~ 64ûû)
~nax
. Ar~al. Cal'd. for CllH~N305-114HzO: C, 48.98; ~ 4.30;
.
Found: C~ 4~.34; H, 4.42;
~la, 15.4~4
Ma~eC~ data or the a~o~e pros~uct ~c~lled BC-L50l ls
If the procedure of Exam~le 26 is repeated using
a-cyanoprop~onic acid ln place of the cyanoa~etic acid
u8et there~n, there is obtained 7B-~a-cyanopropionamido)-
3-methyl-~3-0-2-i~oc phem-4-car~oxyllc acid.
.
Example 27
.: - 7B-~2-(2H~-tetrazolylacetamido~-3-methyl-~3-0-2-
. isocephem-4-carboxylic ac~d
~ N--- N
¦ o ~ ~C-C82CON8~
~, C02H
: . ~ . ..
C82C02Et 2 8t ~ CH2Co2H~H2o
-~ H H
.-i~ l
, ~,.
pl A ~olution of potasslum hydroxide (4,5 g.) in 70 ml.
- of ~bsolute ethanol was added to ~ solution of the above
: 20 ethy~ ester (5.0 g~) in 25 ml~ of absolute ethanol.
After hea~lng ~nder reflux for 30 ~inu~es, ~he solution
s ~vaporated tc drynes~ in v~cuo. The residue was
d~ ol~d ~n 50 ml. wat r and a slurry (5~ ml.) of ion
. *
~xchan~e resin ~Dow~x 50W-X4-acid form~ ~as added. After
br~ ~tirringt ~he resin was filterea OIL- ~ ~he saiu~lon
*T~ade Mar,~
~ t~
tres~ed with charcoal, filtered and evaporated in ~acuo
to give the acid lndicated above as a crystalline s~lid,
3.68 g. (79% y~eld); m.p. 156-158C. CWi~h dec~mposition).
1. W. G~ Flnnegan, R. A. ~enry, R. Lofquist, J~ Am.
Chem Soc. 80, 3908 (1958)
The acylation procedure of Example 24 was repéated
w~h the acylating acid used therein replaced by an equi-
lar weight of 2-(2H)-tetrazoleacet~c acid and ace~onitr~le
used as the solvent. The crude acylation product was
csystalli~ed from ethyl ace~ate to give pure benzyl 7B-~2-
(2H3-tetrazolylacetamido~-3-methyl- G3 0 2 isoc~phem 4
car~oxylate in 4~Z yield; m.p. 169-170 (~-ith decomposition).
Ana~. Calcld. fcr C18HlgN605: C, 54.28; H, 4.5S;.N, 21.1C.
Found: C, 54.37; H, 4.75; N, 20.48.
The mother liquors from the crystalliz~tion of the
above benzyl ester were plsced on ~ 3.5 g. silica gel ~g~ade m
olumn~ Elution with ether/e~hyl acetate gave benzyl 7B-
~ethoxycarb~xa~ldo)-3~methyL-~3-0-2-isocephem-4-carboxylate
~ 21~57O yield which was u~ed in the follswing example.
The benzyl 7~-~2-(2~)-tetrazo~ylace~amida~3-methyl-~ -
0-2-~s~c~ph~-4-c~rboxylate wzs hydrQgenated as in Example
24 to glve the tiele product;
H 2~ 92~
~n~l~ Calc'd for ~ 2N65 ~2~ 1/2~2~ C~ ;
H 5 2?- N 23 13
S ~ 9
~o~nd: C~ 42.99;
~ ~ 5~; N 5 ~3 O ~ ~
M~ C. data fQr the above ~rod~c! (ca~ led B~ LSl~,
T~3 ~ l e ~ ~
. ~ ~
7~ - (Ethoxycar~oxamido) - 3 -methyl - ~3 -O- 2 - isoc e~hem-
4-car~oxYlîo acid
.,
,
. C~3C~20CO~ O
CH3
~2~
Benzyl 7~-(ethoxycar~oxamido)-3-m~thyl-~3-9-2-
i~oceph~m-4-car~oxylate (as produced in Exam~le 37) was
~: hydrogenated as in Example 24 to give the t~tle product.
~.V. A MeOxH 269 (~ . 7600).
~ Anal Calc'd. f~r CllH14N20~ 1/4C2~16~1/4H20: C,-48.25;
~ . .
~, S.63; N, 9.79.
Found: C, 47.9;;
.
,~
~ ~, 5.12; N, 9.92.
, i.
: M. I.C . data for the ~bo~e product (called BC-L52) is
..~
shown ln Table 9.
~215-
Exam~le ~9
7B-~3-~o-chloro~henYl)-5-methyl-isoxazol-~-vlcG.box-
-3-methYl- ~3-0-2-isoce~hem-~-ca-~oxYli~ acid
NH ~ 0
~ ~ C~3
.,. C02K
~:~ To ~ solution of 1.O mmole of benzyl 7~-amino-3-methyl-
A -0-2-~socephem-4-car~oxylic ~cid and 1.10 ~1. triethylamine
. ~n 5 ml. methylene ch~oride was added a solution of i.10 ~mole of
3-(o-chl~rophenyl)-5-methyl-4-isoxaÆole-carboxylic acid
chl~ride in 5 ml. methylene chloride. After 18 hours at
:.~ ~4C., the solution was diluted with 50 ml. ~ethylene
chlos~de and washed with 50 ml. each o~ saturated NaCl,
~,
10% ~Cl, saturated NaHC03 and saturated NaCl. The methylene
. ch~oride solution was dried ~s~di~m sul.cate) and evaporGted
in vacuo to a brown solid wnich was trit~rated ~i~h ether,
___
The solid c.ude acylat~on product ~7as dissolved in
~e~hylene c~loride and absurbed onto 25 g. silica gel (grade
III), The ~lliC2 gel was eluted with methylene chioride, then
ethyl acetate. The ethyl acPt~te extract was t~iturated
wi~h ether to give benzyl 7~-[3-(o-chlo.ophenyl)-5-~ethyl-
l~xazol-4-yl-ceroox~mido]-3-~eehyl- ~ -~-2-isocephe~-4-
216-
~ 5L ';~
~arb~xylate` in 80.5~ yielt; m.p. 100-110C (wit~ decompasitlon).
Hydrogenation of the benzyl ester according to the procedure
of Example 24 gave the title protuct,
~ ~ ~ MeOH 271 ( . 5600) .
Anal Calc~d for ClgHl6clN3o6~c2H2o-H2o C~ S2-34;
~, 5.02; N, 8~72;- Cl~ 7.36
Found: C, 51.81;
H~ 4.54; N, 9.37; Cl, 7.15.
Residue: l.gS%
.~ M.I.C. data for the above product (called BC-~S9) is
~hown in Table 9.
.. .
:
-'
.,
.
-217-
xample 3Q
~ ~ (lH~-Tetrazolylacetamido~-3-methyl-~3-0-2-
isocephem-4-car~oxYlic acid
~ - N
N N- CH2CONH -.
~ ~ ' ' ':
CH3
. ~2H
-l-(lH)-Tetrazolylacetic acid (256 mg.)~ 6.25 ml. of
benzene and 1.25 ml. oxalyl chloride were stirred at 24
. for 3 days. The starting acid was filtered off and evapor-
fltion of ~he solution ga~e l-~lH)-te~razoleacetyl chloride
in 587. y~eld.
. The acylation procedure of Example 29 t~a~ repeated
w~th the acylating acid chloride used therein replaced by
a~ equimolar weight of l-(lH)-tetrazole~cetyl chloride~
. The 801id acyla~ion product, i.e. benzyl 7~-[1-(lH)-
t~trazolylacetamidoi-3-~ethyl-~3-0-2-isocephem-4-carboxy-
l~te, W2~ obtained in 22.5X yield.
Hydrogena~ion of ~he be~zyl ester according to the
pr~cedure of Example ~4 gives the title product,
-21~-
T2~1e 9
. ',.
The Minimum lnhibitory Concen~ra~ions (M.I.C.) of
several of the comp~unds prepared above were determined
against the Indicated microorganisms by the tube di}ution
. a~y procedure. The resul~s are as foll~ws: -
M. I . C . (mc~ . /ml . )
Co~poundS. aureus E. c~liSal. enteriti.dis _. eneuTnoniae
of_Ex. No.A9537 A1511g ~ A9585
0.6 16 ~2.5 0~.~8
16 0~6 63 8 .3
17 ~3 25 >125 32 32
18 2 16 8
19 4 >125 125 0 . 5
125 >125 ~125 125
21 32>125 >125 16
22 ~ 1 125 4 0. 5
23 ~ 32 ~ 0.25
24 16 125 32 4
~5 ~.5>125 >125 0.25
26 4 125 125 0.5
27 >~25>12~ ~2~ 125
28 125>125 ~25 32
2g >~>125 ~125 8
--Zl9~
