Note: Descriptions are shown in the official language in which they were submitted.
1OS9991
This invention is concerned with improvements in
or rélating to cephalosporin compounds, and is more
particularly concerned with a novel class of cephalosporin
compounds possessing valuable antibiotic properties.
The cephalosporin compounds in this specification
are named with reference to "cepham" after J.Amer.~hem.
Soc., 1962, 84, 3400, the term "cephem" referring to the
-
basic cepham structure with one double bond.
Cephalosporin antibiotics are widely used in the
treatment of diseases caused by pathogenic bacteria in
human beings and animals,for example in the treatment of
diseases caused by bacteria which are resistant to other
antibiotics such as penicillin compounds, and in the
treatment of penicillin-sensitive patients. In many
instances it is desirable to employ a cephalosporin anti-
biotic which exhibits activity against both gram positive
and gram negative microorganisms, and a significant amount
of research has been directed to the development of various
types of broad spectrum cephalosporin antibiotics.
-- 2
. .
iossss~
Considerable interest is currently being directed
to the development of broad spectrum cephalosporin anti-
biotics which possess high activity against gram negative
organisms. Existing commercially available ~-lactam anti-
biotics tend to exhibit comparatively low activity againstcertain gram negative organisms such as Proteus organisms,
which are an increasingly common source of infectîon in
humans, and are also generally substantially inactive against
Pseudomonas organisms. Several Pseudomonas organisms are
resistant to the majority of existing commerically available
antibiotic compounds,and the practical therapeutic
applications of aminoglycoside antibiotics such as gentamicin
which do exhibit Pseudomonas activity tend to be limited
or complicated by the high toxicity of these antibiotics.
It is well known that cephalosporin antibiotics normally
exhibit low toxicity in man, so that the development of
broad spectrum cephalosporin antibiotics possessing high
activity against gram negative organisms such as strains of
Proteus and Pseudomonas fulfils a significant need in
chemotherapy.
The present invention provides 7~-acylamidoceph-
3-em-4-carboxylic acid antibiotics of the general
formula
l~ . . .
1059~9~
~ H S
R.C.CO.NH- ¦ ~ ~
R O ~ N ~ P (I)
O.C COOH OOH
[wherein R is a thienyl or furyl group; Ra and Rb, which
may be the same or different, are each selected from
hydrogen, Cl_4 alkyl (e.g. methyl, ethyl, n-propyl,
isopropyl or butyl), C2 4 alkenyl (e.g. vinyl or allyl),
C3 7 cycloalkyl (e.g. cyclopropyl, cyclobutyl, cyclopentyl
or cyclohexyl), phenyl, napthyl, thienyl, furyl, carboxy,
C2 5 alkoxycarbonyl (e.g. ethoxycarbonyl) and cyano, or Ra
and Rb together with the carbon atom to which they are
attached form a C3 7 cycloalkylidene or cycloalkenylidene
group (e.g. a cyclobutylidene, cyclopentylidene or
cyclohexylidene group); and P is selected from:-
a) a group of formula R
-CH = C
\R2
wherein R and R2, which may be the same or different are
each selected from hydrogen, carboxy, cyano, C2 7
alkoxycarbonyl (e.g. methoxycarbonyl or ethoxycarbonyl)~
Cl-C6 alkyl (e.g. methyl, ethyl, iso-propyl or n-propyl),
C5~7 cycloalkyl (e.g. cyclopentyl or cyclohexyl), phenyl
Cl 4 alkyl (e.g. benzyl or phenylethyl) and C6-C12 (mono-
or bicyclic carbocyclic aryl (e g. phenyl, nitrophenyl, tolyl
or napthyl) groups;
~ ~ - 4
,, ,
~OS999~ -
and
b) a group of formula
-CH2Y
wherein Y is selected from:-
5 b)(i) the residue of a nitrogen nucleophile which is atri(Cl 6 alkyl) amine or a heterocyclic tertiary amine~
b)(ii) azido,
b)(iii) amino,
b)(iv) acylamido,
b)(v) a derivative obtained by reacting a compound in
which Y is azido with an acetylenic, ethylenic or cyano
dipolarophile,
b)(vi) a group of formula
R10
C. CO. R
Rll
wherein R and R 1, which may be the same or different,
are each selected from hydrogen; cyano; lower alkyl
e~g. methyl or ethyl; phenyl; phenyl substituted by one or
more of halo, lower alkyl, lower alkoxy, nitro, amino or
lower alkylamino; carboxy; lower alkoxycarbonyl; mono- or
di-aryl lower alkoxycarbonyl; lower alkylcarbonyl; aryl lower
alkyl; and C5and C6 cycloalkyl; and R12 is selectedfrom hydrogen;
lower alkyl e.g. methyl or ethyl; ph:enyl; phenyl substituted
by one or more of halo, lower alkyl, lower alkoxy, nitro,
, i
L~
:lOS999:~
amino or lower alkylamino; aryl lower alkyl; and C5 and c6
cycloalkyl;
b)(vii) the residue of a sulphur nucleophile which is a
thiourea, dithiocarbamate, thioamide, thiosulphate, thioacid
or dithioacid,
b)(viii) a group of formula-
-s (o)nRl3
wherein R13 is a lower alkyl, lower cycloalkyl, phenyl
lower alkyl~ C6_12 mono- or bicyclic carbocylic aryl or
heterocyclic group and n is 0, 1 or 29
b)(ix) a group of formula
-oR15
wherein R 5 is hydrogen, lower alkyl, lower alkenyl,
lower alkynyl, lower cycloalkyl, lower cycloalkyl lower
alkyl, aryl, aryl lower alkyl, heterocyclic, heterocyclic
lower alkyl, or any of the preceding groups substituted
by one or more of lower alkoxy, lower alkylthio, halogen,
lower alkyl, nitro, hydroxy, acyloxy, carboxy, lower
alkoxycarbonyl, lower alkylcarbonyl, lower alkylsulphonyl,
lower alkoxysulphonyl, amino, lower alkylamino and
acylamino,
b)(x) a group of formula
-O .CO .R16
wherein R16 is selected from Cl_7 alkyl (e.g. cl_4 alkyl),
-
lOS999~
which may be interrupted by an oxygen or sulphur atom or by
an imino group or substituted by cyano, carboxy, lower
alkoxycarbonyl, hydroxy, carboxycarbonyl, halogen (e.g.
chlorine, bromine or iodine) or amino; c2 7 alkenyl,
which may be interrupted by an oxygen or sulphur atom
or by an imino group; lower cycloalkyl; carbocyclic or
heterocyclic aryl~ which may be substituted by hydroxy,
halo, nitro, amino, lower alkyl or lower alkylthio;
lower cycloalkyl Cl_4 alkyl; and carbocyclic or hetero-
cyclic aryl Cl 4 alkyl andb)(xi) a group of formula
-O.CO.A R
wherein R17 is hydrogen or a group as defined above for
Rl~ and A is ~ 0, ~ S or ~NH, provided that when R
lS represents a furyl group and P represents a carbamoyloxymethyl
group~ Ra and Rb may not both represent hydrogen or together
with the carbon atom to which they are attached form a
cyclobutylidene group]and non-toxic derivatives thereof,
sa`id compounds being sYn isomers or existing as mixtures
of svn and anti isomers containing at least 90% of the svn
isomer.
These compounds exhibit broad spectrum antibiotic
activity characterised by particularly high activity against
gram negative microorganisms,including those which produce
~-lactamases, and also possess very high stability to
. . - 7 -
LI~
~OS9991
~-lactamases produced by a range of gram negative organisms.
A characteristic feature of the compounds is their
~ high in vitro activity against gram-negative organisms
such as Enterobacter clocae, _rratia marcescens
S and Klebsiella aerogenes. The compounds h~ve particularly
high activity against strains of Escherichia coli,
Haemophilus influenzae and Proteus organisms, e.g.
strains of Proteus mor~anii and Proteus mirabilis,
Compounds wherein at least one of R and R is other than
hydrogen have also shown unusually high activity against
Pseudomonas organisms, for example strains of Pseudomonas
aeru~inosa.
The compounds of the invention are defined as
having the sVn isomeric form as regards the configur-
15 ation of the group
Ra
O . C . COOH
with respect to the carboxamido group. In this specifi-
cation the sYn configuration is denoted structurally as
R.C .CO.NH--
N ~ ~ a
I b
-- 8 --
~:OS9991
this configuration being assigned on the basis of the work
of Ahmad and Spens~r reported in Can. J. Chem., 1961, 39,
1360. As indicated above, the compounds may exist as
mixtures of syn and anti isomers provided that such
mixtures contain at least 90% of the s~n isomer. We prefer,
however, the compounds to be svn isomers essentially free
from the corresponding anti isomer.
By "non-toxic derivatives" is meant those
derivatives which are ph~siologically acceptable in the
dosage at which they are administered. Such derivatives
may include, for example, salts, biologically acceptable
esters, l-oxides and solvates (especially hydrates).
It will be appreciated that derivatives such as salts and
esters may be formed by reaction of either or both of the
carboxyl groups present in the compounds of formula I.
Non-toxic salt derivatives which may be formed
from the compounds of general formula I include inorganic
base salts such as alkali metal salts ~e.g. sodium and
potassium salts) and alkaline earth metal salts (e.g.
calcium salts); organic base salts (e.g. procaine, phenyl-
ethylbenzylamine, dibenzylethylenediamine, ethanolamine,
diethanolamine, triethanolamine and N-methylglucosamine
salts); and, where appropriate, acid addition salts, e.g.
~OS99~
with h~ochloric, hydrobromic, sulphuric, nitric, phos-
phoric, trifluoroacetic, toluene-~ sulphonic and methane
sulphonic acids. The salts may also be in the form
of resinates formed with, for example, a polystyrene resin
or cross-linked polystyrene divinylbenzene copolymer
resin containing amino or quaternary amino groups, or,
where appropriate, sulphonic acid groups, or, again
where appropriate, with a resin containing carboxyl groups,
e.g. a polyacrylic acid resin. Use of highly soluble
base salts (e.g. alkali metal salts such as the sodium
salt) of compounds of formula I is genera~ly advantageous
in therapeutic applications because of the rapid
distribution of such salts in the body upon administration.
Where, however, insoluble salts of compounds (I) are desired
in a particular application, e.g. for use in depot
preparations, such salts may be formed in conventional
manner, for example with appropriate organic amines.
Biologically acceptable, metabolically labile
ester derivatives which may be formed from compounds
of formula I include, for example, acyloxymethyl esters,
e.g. lower alkanoyloxymethyl esters such as acetoxymethyl
or pivaloyloxymethyl esters.
Where the group R in the above formulae is
-- 10 --
LD,
.
lQ599~1
a furyl group it may be fur-2-yl or fur-3-yl and where
it is a thienyl group it may be thien-2-yl or thien-3-yl.
It will be appreciated that when Ra and R in
the above fonmulae are different, the carbon atom to which
they are attached may comprise a centre of asymmetry;
compounds in accordance with the invention wherein R
and R are different may thus be diastereoisomeric. The
invention embraces the individual diastereoisomers of
such compounds as well as mixtures thereof.
When P in formula I above is a vinyl group as
defined under a), this group may be for example a 2-
carboxyvinyl, 2-methoxycarbonylvinyl, 2-ethoxycarbonyl-
vinyl or 2-cyanovinyl.
When Y in formula I above represents the residue
of nitrogen nucleophile as defined under b) (i), this
nucleophile may be for example a tri(cl_6 alkyl~ amine such
as triethylamine, or a heterocyclic tertiary amine which
may if desired contain one or more further hetero-
atoms in addition to the basic nitrogen atom, and may be
substituted or unsubstituted. The heterocy~lic tertiary
amine may th~s, for example,be a pyridine, pyrimidine,
pyridazine, pyrazine, pyrazole, imidazole, triazole or
thiazole; a fused bi- or poly-cyclic analogue of any of these
heterocycles, for example purine or benzotriazole; and any
25 of the above ~mines substituted by one or more aliphatic
lOSg99~ . .
(e.g. lower alkyl such as methyl, ethyl, n-propyl or iso-
propyl), aryl (e.g. C6 12 mono- or bicyclic carbocyclic aryl
such as phenyl or naphthyl), araliphatic (e.g. phenyl lower
alkyl such as benzyl or phenylethyl), lower alkoxymethyl
(e.g. methoxym~thyl, ethoxymet~yl, n-propoxymethyl or i90-
propoxymethyl), acyloxymethyl (e.g. lower alkanoyloxymethyl
such as acetoxymethyl), formyl, acyloxy (e.g. lower
alkanoyloxy such as acetoxy), carboxy, esterified carboxy
(e.g. lower alkoxycarbonyl such as methoxycarbonyl), carboxy
lower alkyl (e.g. carboxymethyl), sulpho, lower alkoxy (e.g.
methoxy, ethoxy, n-propoxy or iso-propoxy), aryloxy
(e.g. phenoxy), aralkoxy (e.g. benzyloxy), alkylthio
(e.g. methylthio or ethylthio), arylthio, aralkylthio,
cyano, hydroxy, carbamoyl, N-monoloweralkylcarbamoyl
(e.g. N-methylcarbamoyl or N-ethylcarbamoyl), N,N-dilower-
alkylcarbamoyl (e.g. N,N-dimethylcarbamoyl or N,N-
diethylcarbamoyl), N-(hydroxyloweralkyl)carbamoyl
(e.g. N-(hydroxymethyl)carbamoyl or N-(hydroxyethyl)-
carbamoyl), or carbamoylloweralkyl (e.g. carbamoylmethyl
20 or carbamoylethyl) groups. Examples of Y groups which
may be obtained from heterocyclic tertiary amine
nucleophiles of the above type include pyridinium,
3- and ~-carbamoylpyridinium, 3-carboxymethylpyridinium,
3-sulphopyridinium, thiazol-3-yl, pyrazol-l-yl,
- 12 -
..
1059991.
pyridazininium, and benzotriazol-l-yl.
Another class of nitrogen nucleophiles comprises
azides, e.g. alkali metal azides such as sodium azide.
Compounds in which Y is amino may be deri~ed from
the corresponding comp~und in which Y is azido by reduction,
e.g. by catalytic hydrogenation of the azide using a precious
metal catalyst such as palladium or platinum. Compounds in
which Y is an acylamido group may be derived by acylation ofa
compound wherein Y is amino, e.g. by any method suitable
for acylating an aminocephalosporin, for example reaction
of the amino compound with an acid chloride, acid
anhydride or mixed anhydride of an acid corresponding
to the desired acyl group and another acid.
Compounds wherein Y is amino may also be
reacted with a substituted isocyanate or isothiocyanate
to yield urea or thiourea derivatives.
Other compounds in which Y is a derivative of a
residue of a nitrogen nucleophile may be obtained by
reacting a compound in which Y is azido with a dipolar-
ophile. Examples of suitable dipolarophiles includeacetylenic, ethylenic and cyano dipolarophiles.
Acetylenic dipolarophiles may be shown as having
the structure
R3. C - C .R4
- 13 -
i~l
105999~
wherein R3 and R4, which may be the same or different, are
atoms or groups.
In general we prefer that R and preferably also
R4 should be of an electronegative nature. Ex~mples of
such groups include cyano, Co2R5, COR5 (where R5 is,
for example, hydrogen, lower alkyl, aryl or lower aralkyl),
and trihalomethyl e.g. trifluoromethyl.
However, R and preferably also R4 could be
electropositive e.g. alkoxy or alkylamino.
R and R may together form a ring system with the
acetylenic group such as, for example, in an aryne.
Where R and R are discrete atoms or groups which
are identical a single compound will result on reaction
with the azido cephalosporin; if they are different one
15 will in general obtain a mixture of position isomers.
Ethylenic dipolarophiles may be shown as having
the structure
R6~ R8
C = C
R7 / \ R
where R , R , R and R which may be the same or different
20 are atoms or groups. Although R , R , R and R may
all be hydrogen, ethylene per se, like acetylene, reacts
sluggishly with azido groups. R and R may together form
- 14 -
~OS9991
a cyclic structure, e.g. a carbocyclic structure, with the
ethenoid group such that the double bond is strained.
Examples of ethylenic dipolarophiles containing strained
double bonds include norbornenes, transcycloalkenes and
S acenaphthalene.
Further ethylenic dipolarophiles which may be
used include compounds of the f~rmula R . R C = CR . R9
where at least one of R , R , R and R is an electro-
negative group. R6 and R may thus be identical electro-
negative groups, R and R being other groups as desired.
R and R may thus together form a ring system. Examples
of such dipolarophiles include benzoquinone and nuclear
substituted benzoquinones and maleimide. Again all of
R , R , R and R may be identical electronegative groups.
Electronegative groups which may be used include those
listed under the section on acetylenîc dipolarphiles
and examples of such compounds thus include dicyanoethylene
and lower mono- and di-alkoxycarbonyl ethylenes.
One or more of R , R , R and R may if desired
be electropositive.
Cyano compounds, especially those which are
activated by electronegative groups, may function as cyano
- 15 -
D
1059991
dipolarophiles. Examples of such dipolarophiles include
lower alkoxycarbonyl cyanides and cyanogen.
When Y in formula I above represents the residue
of a sulphur nucleophile, as defined under b) (vii), this
nucleophile comprises thioureas, including
allphatic, aromatic, araliphatic, alicyclic and
heterocyclic substituted thioureas; dithiocarbamates;
aromatic, aliphatic and cyclic thioamides, for example
thioacetamide and thiosemicarbazide; thiosulphates;
thiols; thiophenols; thioacids, e.g. thiobenzoic acid
or thiopicolinic acid; and dithioa¢ids.
Sulphur n~cleophile residues as defined under b) (viii)
comprise those of compounds of the formula: R13.S(o) H in
which R13 is a lower alkyl such as methyl, ethyl or
n-propyl group; a lower cycloalkyl such as cyclohexyl or
cyclopentyl group; a C6 12 mono- or bicyclic carbocyclic
aryl such as phenyl or naphthyl group; a phenyl lower
(e.g. Cl 4) alkyl such as benzyl group; or a heterocyclic
group, and n is 0, 1 or 2. A preferred class of nucleo-
philes falling within the above formula is that havingthe general formula R14 SH in which R14 is lower alkyl
such as methyl, ethyl or n-propyl; phenyl lower alkyl
such as benzyl or phenethyl or substituted phenyl lower
alkyl; cycloalkyl such as cyclopentyl or cyclohexyl;
aromatic, e.g. phenyl, substituted phenyl or a hetero-
-16 -
Dl
105999~
cyclic group containing at least one 5- or 6-membered ring
and having one or moreheteroatoms selected from o, N and S.Such
heterocyclLc groups R14 may be substituted, and examples
of suitable heterocyclic groups includes thiadiazolyl, eOg.
5-methyl-1,3,4-thiadiazol-2-yl; diazolyl; triazolyl, e.g.
triazol-4-yl; tetrazolyl, e.g. 1-methyltetrazol-5-yl,
l-ethyltetrazol-5-yl or 1-phenyltetrazol-5~yl; thiazolyl;
thiatriazolyl; oxazolyl; oxadiazolyl, e.g. 2-phenyl-1,3,~-
oxadiazol-5-yl; pyridyl, e.g. N-methylpye~d-2-yl;
pyrimidyl; fused heterocyclic ring systems such as benz-
imidazolyl, benzoxazolyl, benzothiazolyl such as benzothia-
zol-2-yl, triazolopyridyl or purinyl; and substituted
versions of such fused ring systems, e.g. nitrobenzothia-
zol-2-yl such as 5- or 6-nitrobenzothiazol-2-yl.
When Y in formula I above represents the residue
of an oxygen nucleophile as defined under b) (ix), this
nucleophile comprises compounds of the following for,mula:
Rl 50H
in which the group R15 may be hydrogen, lower alkyl (e.g.
methyl, ethyl, n-propyl, isopropyl, n-butyl or isobutyl);
lower alkenyl (e.g. allyl); lower alkynyl(e.g. propynyl);
lower cycloalkyl (e.g. cyclopropyl, cyclopentyl or
cyclohexyl); lower cycloalkyl lower alkyl (e.g.
- 17 -
r~
LL~
~os999~
cyclopropylmethyl, cyclopentylmethyl or cyclohexylethyl);
aryl (e.g. phenyl or naphthyl) ; aryl lower alkyl
(e.g. benzyl~; heterocyclic(e.g. a heterocyclic group as
defined for R 4, such as N-methylpyrid-2-yl); heterocyclic
lower alkyl (e.g. furfuryl); or any of these groups
substituted by one or more of lower alkoxy
(e.g. methoxy or ethoxy), lower alkylthio (e.g. methylthio
or ethylthio), halogen (chlorine, bromine, iodine or
fluorine), lower alkyl (e.g. methyl or ethyl), nitro,
hydroxy, acyloxy, carboxy, carbalkoxy, lower alkylcarbonyl,
lower alkylsulphonyl, lower alkoxysulphonyl, amino,
lower alkylamino or acylamino groups.
In the case in which water is the nucleophile
there will be obtained 3-hydroxymethyl cephalosporin
compounds. Such 3-hydroxymethyl compounds and non-
toxic derivatives thereof may show antibacterial
activity and it is of note that they may be metabolites
of compounds of general formula II where P is acetoxymethyl.
3-Hydroxymethyl cephalosporins may be acylated to form
derivatives characterized by possessing the group 3-CH2.
O.CO.R or 3-CH2.O.CO.AR where A is 0, S or NH, R
is an organic group and R17 is hydrogen or an
organic group.
- 18 -
J . ,
~OS9991
Examples of the group R include
(i) methyl, ethyl, propyl, isopropyl, n-butyl, t-butyl,
sec.butyl and 2-chloroethyl;
(ii) vinyl and propenyl;
(iii) C6 12 mono- or bicyclic carbocyclic aryl, heterocyclic
aryl comprising a 5- or 6-membered ring containing at
least one of O, N and S, lower cycloalkyl, substituted aryl
and substituted cycloalkyl, examples of this group including
phenyl; substituted phenyl e.g. hydroxyphenyl, chlorophenyl,
fluorophenyl, tolyl,nitrophenyl, aminophenyl, methoxyphenyl
or methylthiophenyl; thien-2- and -3-yl; pyridyl; cyclo-
hexyl; cyclopentyl; cyclopropyl; sydnone; naphthyl; and
substituted naphthyl e.g. 2-ethoxynaphthyl; and
(iv) methyl, ethyl or butyl substituted by the various
specific groups listed under (iii), e.g.
lower cycloalkyl Cl 4 alkyl and carbocyclic or heterocyclic
aryl Cl 4 alkyl such as benzyl and the appropriate
substituted benzyl groups.
3-Position substituents of the above type thus
include lower alkanoyloxymethyl groups such as
acetoxymethyl and isobutyryloxymethyl, lower alkenoyl-
oxymethyl groups such as crotonyloxymethyl; aroyloxymethyl
groups such as benzoyloxymethyl; carbamoyloxymethyl,
-- 19 --
lOS9991
N-(lower alkyl)carbamoyloxymethyl such as N-methylcarbamoy-
loxymethyl, and N-(haloalkyl)carbamoyloxymethyl such as
N-(2-chloroethyl)carbamoyloxymethyl.
The term "lower" as used in this specification and
the accompanying claims to qualify aliphatic groups denotes,
unless otherwise stated, that the said group may contain up
to 6 carbon atoms. "Lower" as used to qualify cycloaliphatic
groups indicated that the group may contain 3-7 (e.g. 5-7)
carbon atoms.
A particularly interesting class of
cephalosporin antibiotics in accordance with the invention
comprises compounds of general formula
H H
R,~,CO.NI~ S
N ~ W (II~
O . ~ . COOH '' COOH
~d
[wherein R is as hereinbefore defined, Rc represents
methyl, ethyl, propyl, allyl or phenyl and Rd represents
hydrogen, carboxy or, more preferably, a group as defined
for RC; or Rc and Rd together with the carbon atom to which they
are attached fonm a cyclobutylidene, cyclopentylidene or
cyclohexylidene group; and W is selected from:-
- 2~ -
~OS999i
i) acetoxymethyl,
ii) benzoyloxymethyl
iii) carbamoyloxymethyl,
iv) N-methylcarbamoyloxymethyl,
5 v) a group of formula
-CH=CHRZ
(where RZ represents cyano, carboxy or a C2_5
alkoxycarbonyl group such as methoxycarbonyl or ethoxy-
carbonyl),
vi) the group -CH2G where G is the residue of a nitro-
gen nucleophile selected from compounds of the formula
~ . .
. ~ ~ f
(wherein R is hydrogen, carbamoyl, carboxymethyl or
sulpho) and pyridazine,
vii) azidomethyl, and
viii) the group -CH2SRW wherein Rw is selected from
pyridyl, diazolyl, triazolyl, tetrazolyl, thiazolyl,
thiadiazolyl, oxadiazolyl, and substituted
(e.g. lower alkyl- or phenyl-substituted) versions of
these groups such as N-methylpyrid-2-yl, l-methyltetrazol-
5-yl, 1-phenyltetrazol-5-yl; 5-methyl-1,3,6-thiadiazoi-2-yl
- 21 -
LD,,.
105999~
and 5-phenyl-1,3,4-oxadiazol-2-yl~
and non-toxic deri-vatives thereof.
These compounds exhibit broad spectrum antibiotic
activity (including very high activity against strains of
S Haemophilus influenzae and Proteus organisms) and high
~-lactamase stability and are further characterised by
particularly high in vitro activity against Pseudomonas
organisms such as strains of Pseudomonas aeruginosa.
Especially preferred compounds of the above
type, by virtue of their particularly high levels of
activity against Proteus and Pseudomonas organisms,
include the following:-
(6R,7R~-7-¦2-(2-carboxyprop-2-yloxyimino)-2-(fur-2-yl)
acetamido]-3-pyridiniummethylceph-3-em-4-carboxylic acid
(syn isomer),
(6R,7R)-7-¦2-(2-carboxyprop-2-yloxyimino)-2-(fur-2-yl)
acetamido~-3-(S-methyl-1,3,4-thiadiazol-2-ylthiomethyl)ceph-3-
em-4-carboxylic acid (syn isomer),
(6R,7R)-3-carbamoyloxymethyl-7-[2-(2-carboxyprop-2-yloxyimino)-
2-(fur-2-yl)acetamido]ceph-3-em-4-carboxylic acid (syn
isomer),
(6R,7R)-7- L 2-(2-carboxyprop-2-yloxyimino)-2-(fur-2-yl)acetamido]
-3-(trans-2-methoxycarbonylvinyl)ceph-3-em-4-carboxylic acid
- 22 -
~05999i
(syn isomer),
(6R,7R)-7-[2-(2-carboxyprop-2-yloxyimino)-2-(fur-2-yl)
acetamido]-3-pyradiziniummethylceph-3-em-4-carboxylic acid
(svn isomer),
(6R,7R)-3-acetoxymethyl-7-[2-(1-carboxycyclopent-1-yloxyimino)-
2-(fur-2-yl)acetamido]ceph-3-em-4-carboxylic acid (syn isomer~,
(6R,7R)-7-[2-(1-carboxycyclopent-1-yloxyimino)-2-(fur-2-yl)
acetamido]-3-pyridiniummethylceph-3-em-4-carboxylic acid (syn
isome~,
(6R,7R)-7-[2-(1-carboxycyclopent-1-yloxyimino)-2-(fur-2-yl)
- acetamido]-3-(trans-2-carboxyvinyl)ceph-3-em-4-carboxylic
acid (syn isomer),
(6R,7R)-7-[2-(1-carboxycyclopent-1-yloxyimino)-2-
(fur-2-yl)acetamid4]-3-(l-methyltetrazol-S-ylthiomethyl)
ceph-3-em-4-carboxylic acid (syn isomer),
(6R,7R)-3-carbamoyloxymethyl-7-[2~-carboxycyclopen~-1-
yloxyimino)-2-(fur-2-yl)acetamido]ceph-3-em-4-carboxylic
acid (svn isomer),
(6R,7R)-3-acetoxymethyl-7-[2-(1-carboxybut-3-enyloxyimino)-2-
(fur-2-yl)acetamido]ceph-3-em-4-carboxylic acid (syn isomer),
(6R,7R?-3-acetoxymethyl-7-[2-(1-carboxycyclobut-1-yloxyimino)-
- 23 -
L ~.i
.,
~OS9g91
Z-(fur-2-yl)acetamido]ceph-3-em-4-carboxylic acid ~syn
somer),
(6R,7R)-7-[2-(1-carboxycyclobut-1-yloxyimino)-2-
(fur-2-yl)acetamido]-3- pyridiniummethylceph-3-em-
4-carboxylic acid (synisomer),
(6R,7R)-7-[2-(1-carboxycyclobut-1-yloxyimino)-2-
(fur-2-yl)acetamido]-3-(1-methyltetrazol-5-ylthiomethyl)
ceph-3-em-4-carboxylic acid (svn isomer),
(6R,7R)-3-acetoxymethyl-7-[2-(1-carboxypropoxyimino)-2-
10 (fur-2-yl)acetamido]ceph-3-em-4-carboxy~c acid (8Yn ~omer),
(6R,7R)-3-acetoxymethyl-7-[2-(3-carboxypent-3-yloxyimino)-2-
(fur~2-yl)acetamido]ceph-3-em-4-carboxylic acid (syn isomer),
(6R,7R)-3-acetoxymethyl-7-[2-(2-carboxyprop-2-yloxyimino)-2-
(thien-2-yl)acetamido]ceph-3-em-4-carboxylic acid (syn isomer),
15 and non-toxic derivatives thereof, e.g. alkali metal salts
such as the sodium or potassium salts.
A further interesting class of cephalosporin
antibiotics in accordance with the invention comprises
compounds of general formula
- 24 -
iD~
105999~
H H
R.C.CO.NH ~ ~ (IV)
N J ~ W
\ COOH
O.(CH2)p.COOH
[wherein R and W are as hereinbefore defined and p is 1 or 2]
and non-toxic derivatives thereof.
These compounds exhibit broad spectrum antibiotic
activity coupled with high ~-lactamase stability. A
characteristic feature of the compounds ~s their high
activity against strain~ of Haemophilus influenz~e coupled
with their particularly high activity against ~trains of
Escherichia coli and Proteus or~anisms.
-
Especially preferred compounds of the above type,
by virtue of their particularly high levels of activity
against Escherichia coli and Proteus organisms, include the
following:-
(6R,7R)-3-acetoxymethyl-7-[2-carboxymethoxyimino-2-
(fur-2-yl)acetamido]ceph-3-em-4-carboxylic acid(syn isomer),
(6R,7R)-3-azidomethyl-7-[2-carboxymethoxyimino-2-
(fur-2-yl)acetamido]ceph-3-em-4-carboxylic acid
(~y~ isomer),
- 25 -
~, , .
L . .
105999~ .
(6R,7R~-7-[2-carboxymethoxyimino-2-(fur-2-yl)
acetamido]-3-(1-methyltetrazol-5-ylthiomethyl)ceph-3-
~ em-4-carboxylic acid (syn isomer),.
and non-toxic derivatives thereof, e.g. alkali metal
salts such as the sodium or potassium salts.
The compounds according to the invention may be
prepared by any convenient method, for example by
techniquesanalogo~s to those described in Belgian Patent
No. 783449.
Thus according to one embodiment of the lnvention we
provide a process for the preparation ofan antibioticcompound of
general formula I as hereinbefore defined or a non-toxic
derivative thereof wherein (A) a compound of the formula
H H
H2N' i i~
~ ~~P (V)
COORl9
(wherein P is as defined above; B is >S or ~S ~o; Rl9
represents hydrogen or a carboxyl blocking group, e.g.
the residue o~ an ester-~on~ing aliphatic or
araliphatic alcohol or an ester-forming phenol, silanol
or stannanol (the said alcohol, phenol, silanol or
- 26 -
3~05999~,
stannanol preferably containing 1-20 carbon atoms) or a
sy~unetrical or mixed anhydride group derived from anappropriate
acid; and the dotted line bridging the 2-, 2- and 4-
positions indicates that the compound is a ceph- 2-em or
ceph - 3-em compound) or an acid addition salt suc~ as a
hydrochloride, hydrobromide, sulphaté, nitrate, phosphate,
methane sulphonate or tosylate, or an N-silylated deriva-
tive thereof, is reacted with an acylating agent correspond-
ing to an acid of formula
R~C.COOH
N Ra (VI)
\ O.C.COOR
Rb
(wherein R, Ra and Rb are as hereinbefore defined and R20 i5
a carboxyl blocking group); or (B), where P in formula (I)
is the group -CH2Y
(where Y is as defined above) a compound of the formula
H H
R.C ~ CH2Y
O I COORl9 COOR
Rb
(wherein B,R,Ra, Rb and the dotted line are as hereinbefore
defined; each R 9 may independently represent hydrogen or a
carboxyl blocking group; Y' is a replaceable residue of a
- 27 -
.. i
. .,_
105999~
nucleophile, e.g. an acetoxy or dichloroacetoxy group or a
halogen atom such as chlorine, bromine or iodine)
is reacted with a nucleophile serving to introduce the de-
sired group Y; whereafter, if necessary and/or desired in
each instance, any of the following reactions (C) in any
appropriate sequence, are .carried out:-
i ) conversion of a ~2 isomer into the desired ~3
isomer,
ii ) reduction of a compound wherein B is ~S-~0 to
form a compound wherein B is >S,
iii) reduction of a 3-azidomethyl compound to form a
3-aminomethyl compound,
iv) acylation of a 3-aminomethyl compound to form a
3-acylaminomethyl compound,
15 v) reaction of a 3-azidomethyl compound with a
dipolarophile to form a compound having a polyazole
ring linked to the 3-position carbon atom through
a methylene group,
vi) deacylation of a 3-acyloxymethyl compound to form
a 3-hydroxymethyl compound,
vii) acylation of a 3-hydroxymethyl compound to form
a 3-acyloxymethyl compound,
- 28 -
~ ,
1059991
viii) carbamoylation of a 3-hydroxymethyl compound to
form an unsubstituted or
substituted 3-carbamoyloxymethyl compound, and
ix) removal of carboxyl blocking groups;
and finally (D) recovering the desired compound of
formula I or a non-toxic der~vative thereof, if necessary
after separation of isomers.
Non-toxic derivatives of the compounds of formula
I may be formed in any convenient way, for example
according to methods well known in the art. Thus, for
example, base salts may be formed by reaction of the
cephalosporin acid with sodium 2-ethylhexanoate or
potassium 2-ethylhexanoate. Biologically acceptable
ester derivatives may be formed using conventional
esterifying agents. l-Oxides may be formed by treatment
of the corresponding cephalosporin sulphide with an
appropriate oxidising agent, for example with a peracid
such as metaperiodic acid, peracetic acid, monoperphthalic
acid or m-chloroperbenzoic acid, or with t-butyl
hypoch-lorite, this last reagent conveniently being
employed in the presence of a weak base such as pyridine.
- 29 -
I i
~055~9~
Acylating agents which may be employed in the
preparation of compounds of formula I include acid halides,
particularly acid chlorides or bromides. Such acylating
agents may be prepared by reacting an acid (VI) or a
salt thereof with a haiogenating agent e.g. phosphorus
pentachloride, thionyl chloride or oxalyl chloride.
Treatment of the sodium, potassium or triethylammonium
salt of the acid(VI) with oxalyl chloride is advahtageous
in that under these conditions isomerisation is minimal.
Acylations employing acid halides may be effected
in aqueous and non-aqueous reaction media, conveniently
at temperatures of from -50 to +50C, preferably -20
to +30C, if desired in the presence of an acid binding
agent. Suitable reaction media include aqueous ketones
such as aqueous acetone,- esters such as ethyl acetate,
halogenated hydrocarbons such as methylene chloride,
amides such as dimethylacetamide, nitriles such as
acetonitrile, or mixtures of two or more such solvents.
Suitable acid binding agents include tertiary amines
(e.g. triethylamine or dimethylaniline), inorganic bases
(e.g. calcium carbonate or sodium bicarbonate), and
51
105~991
oxiranes such as lower 1,2-alkylene oxides (e.g. ethylene
oxide or propylene oxide) which bind hydrogen halide
liberated in the acylation reaction.
Acids of formula VI may themselves be used as
acylating agents in the preparation of compounds of
formula I. Acyiations employing acids(V~ ~re desirably
conducted in the presence of a condensation agent, for
example a carbodiimide such as N,N'-diethyl-, dipropyl-
or dl~sopropylcarbodiimide, N,N'-dicyclohexylcarbodiimide
or N-ethyl-N'-r-dimethylaminopropylcarbodiimide; a
carbonyl compound such as carbonyldiimidazole; o~ an
isoxazolinium salt such as N-ethyl-5-phenylisoxazolinium
perchlorate. Acylation reactions of this type are
desirably effected in an anhydrous reaction medium, e.g.
15 methylene chloride, dimethylformamide or acetonitrile,
Acylation may also be effected with other amide-
forming derivatives of acids of formula VI such as, for
example, a symmetrical anhydride or a mixed anhydride
(e.g. with pivalic acid or formed with a haloformate
20 such as a lower alkylhaloformate). The mixed or
- 31 -
~ ... .
,
lOS999~
symmetrical anhydride may be generated in situ; thus,
for example, a mixed anhydride may be generated using
N-ethoxycarbonyl-2-ethoxy-1,2-dihydroquinoline. Mixed
anhydrides may also be formed with phosphorus acids (for
5 example phosphoric or phosphorous acids), sulphuric acid
or aliphatic or aromatic sulphonic acids (for example
~-toluene sulphonic acid).
It will be appreciated that in processes for
the preparation of compounds of formula I wherein Ra or
10 Rb reprecen~ carboxy it will in many instance~
be necessary to protect the carboxy group, for
example by substitution with a carboxyl blocking group,
e.g. a group as hereinbefore defined in connection with
Rl9
Any transformations of substituents at the
3-position which may be necessary in the preparation of
particular compounds of formula I may, for example, be
- effected by methods described in the literature.
- 32 -
~osg99~
Thus, for example, compounds substituted at the
3-position by a group
- CH2Y
wherein Y represents an ether or thioether group or a
halogen atom may be prepared as described in Brltish Patents
Nos. 1,241,656; 1,241,657; 1,277,415 and 1,279,402. Compounds
wherein Y is the residue of a nucleophile may also be prepared
by the reaction of a 3-acetoxymethyl cephalosporin
compound with a nucleophile, for example pyridine or
other tertiary amine as described in British Patent No.
912,541; a sulphur-linking, nitrogen-linking or inorganic
nucleophile as described in British Patent No. 1,012,943;
a sulphur-linking nucleophile as described in British
Patents Nos. 1,059,562; 1,101,423 and 1,206,305; or a
nitrogen-linking nucleophile as described in British
Patents Nos. 1,030,630; 1,082,943 and ~082,962.Compounds in which
Y is a derivative of a residue of a nucleophile, e.g.
where Y is an amino or acylamido group derived from an
azido group may be prepared as described in British Patents
Nos. 1,Q57,883 and 1,211,694,these patents further describing
the reaction of compounds in which Y is azido with a
dipolarophile. Compounds wherein Y is the
- 33 -
~059~91
residue of a nucleophile may also be prepared by the reaction
of a 3-halomethylcephalospDrin with any of the nucleophiles
disclosed in the above references, such a process being
described in British Patent No. 1,241,657, or by the reaction
of a 3-halomethylcephalosporin sulphoxide with any of the
nucleophiles disclosed in the above references, such a process
being described in British Patent No. 1,3~6,531. The contents
of the above mentioned British Patents are herein incorporated
for reference purposes.
Where a 3-halomethylcephalosporin sulphide or sulphoxide
ester is reacted with a tertiary nitrogen nucleophile such
as pyridine in accordance with the process of British Patent
No~ 1,241,657 or 1,326,531, the reaction product will usually
be obtained in the form of, for example, the corresponding
3-pyridiniummethyl halide. It has been observed that
deesterification of compounds of this type byt~eatment with
trifluoroacetic acid tends to promote isomerisation of the
oxy~mino moiety in the 7~-acylamido side chain; such
isomerisation is clearly undesirable if a product containing
at least 90V/o of the ~y~ isomer is to be obtained without the
need for a subsequent isomer separation stage.
It has also been observed, however, that the tendency
- 34 -
10S9991
to isomerisation may be substantially lessened if the
3-pyridiniummethyl halide is converted into the 3-pyridinium-
methyl salt of a non-hydrohalic acid (e.g. trifluoroacetic,
acetic, formic, sulphuric, nitric or phosphoric acid) prior
to deesterification. Conversion of the halide salt into a
non-hydrohalic acid salt is conveniently effected by means
of anion exchange. This may be brought about by, for
example, use of ~ suitable anion exchange resin, for example
in the trifluoroacetate form. Where an anion exchange resin
is employed, the 3-pyridiniummethyl halide may be run through
a column of the resin prior to deesterification. Where the
3-pyridiniummethyl cephalosporin compound is a sulphide, it
may be advantageous to employ an inert organic solvent
system (i.e. one which does not have a harmful effect on the
resin) to ensure adequate solubility for the cephalosporin
compound; organic solvent syste~s which may be used include
lower alkanols such as ethanol, ketones such as acetone, and
nitriles such as acetonitrile. Where the 3-pyridiniummethyl
cephalosporin compound is a sulphoxide it may be preferable
to employ an aqueous solvent system; the use of aqueous sys-
tems may promote simultaneous deesterification of the
cephalosporin compound when, for example, an anion exchange
resin in the trifluoracetate is employed.
~05999~
Compounds possessing a 3-substituent
CH2Y
wherein Y is a hydroxy group may be prepared by the methods
described in British Patent No. 1,121,308 and Belgian
Patent No. 841,937.
Carbamoylation of 3-hydroxymethyl compounds may
be effected by conventional methods. Thus, for example,
a 3-hydroxymethyl cephalosporin may be reacted with an
isocyanate of formula R .NC0 (wherein R represents a
labile substituent group or an alkyl group) to give a
compound containing a 3-position substituent having the
formula -CH2O.CONHRe (wherein Re has the above defined
meaning). Where R is a labile substituent this
substituent may if desired sub~equently be cleaved,
e.g. by hydrolysis, to form a 3-carbamoyloxymethyl group.
Labile groups Re which are readily cleavable upon subsequ-
ent treatment include chlorosulphonyl and bromosulphonyl;
- 36 -
~D.~
~ OS999~
halogenated lower alkanoyl groups such as dichloroacetyl
and trichloroacetyl; and halogenated lower alkoxycarbonyl
groups such as 2,2,2-trichloroethoxycarbonyl. These labile
Re groups may generally be cleaved by acid or base
catalysed hydrolysis (e.g. by base catalysed hydrolysis
using sodium bicarbonate).
Another carbamoylating agent of use in the
carbamoylation of 3-hydroxymethyl cephalosporins is cyanic
acid, which is conveniently generated in situ ~rom, for
example, an alkali metal cyanate such as sodium cyanate,
the reaction being facilitated by the presence of an acid,
e.g. a strong organic acid such as trifluoroacetic acid.
Cyanic acid effectively corresponds to a compound of
formula Re.NC0 wherein Re is hydrogen, and therefore
converts 3-hydroxymethyl cephalosporin compounds directly
to their 3-carbamoyloxymethyl analogues.
3-Hydroxymethyl cephalosporins for use in the above
carbamoylation reactions may, for example, be prepared
by the methods described in British Patent No. 1,121,308
and Belgian Patents Nos. 783,449 and 841,937.
- 37 -
~05999~
Cephalosporin compounds possessing an acylo~methyl
group as 3-position substituent may, for example, be
prepared from a cephalosporin compound having a -CH2X
group (where X = OH or the residue of an acid H X which
has a pKa of not more that 4.0, preferably not rnore than
3.5, as measured in water at 25C) at the 3-position.
X may thus, for example, represent chlorine, bromine,
iodine, formyloxy, an acetoxy group having at least
one electron-withdrawing substitutent on the a-carbon
atom, or a nuclear substituted benzoyloxy group (the
nuclear substituent being of the electron withdrawing
type as described in British Patent No. 1,241,657), and
the nucleophilic displacement reaction to form the desired
3-position acyloxymethyl may be carried out as described
in our aforesaid British Patent No. 1,241,657.
Alternatively, where X is hy(~roxy, a 3-acyloxymethyl
cephalosporin may be obtained by acylation analogous with
that described in British Patent No. 1,141,293, i.e. by
aralkylating the 4-carboxy group, acylating the 3-h~droxy-
methyl group of the protected compound and subsequently
removing the aralkyl group.
- 38 -
iD~
~ 059
Compounds having a vinyl or substituted v ~yl group
at the 3-position may be obtained by the method described
in Belgian Patent No. 761,897.
~ -Cephalosporin ester derivatives obtained in
accordance with the process of the invention may be
converted into the corresponding ~3 derivative by, for
example, treatment of the ~2 ester with a base.
Ceph-2-em reaction products may also be oxidised to
yield the corresponding ceph-3-em l-oxide, for example by
reaction with a peracid as mentioned previously; the
resulting sulphoxide may, if desired, subsequently be
reduced as described hereinafter to yield the corresponding
ceph-3-em sulphide.
Where a compound is obtained in which B is >S~ 0
this may be converted to the corresponding sulphide by,
for example, reduction of the corresponding acyloxy-
sulphonium or alkyloxysulphonium salt prepared in situ
by reaction with e.g. acetyl chloride in the case of an
acetoxysulphonium salt, reduction being effected by, for
example, sodium dithionite or by iodide ion as in a
solution of potassium iodide in a water miscible solvent
e.g. acetic acid, tetrahydrofuran, dioxan, dimethyl-
formamide or dimethylacetamide. The reaction may be
- 39 -
,, . ,i ~
~05999~:
effected at a temperature of -200 to +50C.
Where a compound of formula I is obtained as a mixture
of isomers, the syn isomer may be obtained by, for example,
conventional methods such as crystallisation or chroma-
tography. Syn and a isomers may be distinguished by
appropriate techniques, e.g. by their ultraviolet spectra,
by ~hin layer or paper chromatography or by their proton
magnetic resonance spectra. Thus, for example, the p.m.r.
spectra of ~MS0-d6 solutions of syn compounds of Formula I
exhibit the doublet for the amide NH at a lower ~ield than
do similar solutions of the corresponding anti-isomers.
These factors may be employed in monitoring reactions.
Acids (VI) may be obtained by reacting a glyoxylic
acid of formula
R.Co.COOH (VIII)
(where R has the above-defined meaning) or an ester
thereof with a hydroxylamine derivative of formula
Ra
H2N.o.C.CooR (IX)
Rb
(where Ra, Rb and R20 have the above-defined meanings).
The rssulting acid or ester may be separated
into its syn and anti isomers by, for example,
- 40 -
Dj~
~05999~
- crystallisation, chromatography or distillation,
whereafter ester derivatives may be hydrolysed to yield
the corresponding acid.
Acids (VI) may also be prepared by etherification
of an acid of formula
R.C.COOH
..
N~ (X)
OH
(where R has the above-defined meaning), e.g. by reaction
with a compound of general formula
Ra
T.C.COOR (XI)
Rb
(wherein Ra, Rb and R20 are as hereinbefore defined
and T is halogen such as chloro, bromo or iodo; sulphate;
or sulphonate such as tosylate). Separation of isomers
may be effected either before or after such etherification.
The e~herification reaction is desirably carried out in
the presence of a base, e.g. potassium t-butoxide or
sodium hydride, and is preferably conducted in an organic
solvent, for example dimethylsulphoxide, a cyclic ether
- 41 -
. ~ ,
~. . ., ~
105999~
such as tetrahydrofuran or dioxan, or an N,N-disubstituted
amide such as dimethylformamide. Under these conditions
the configuration of the oximino group is substantially
unchanged by the etherification reaction.
Carboxyl blocking groups R and, where appropriate,
Rl9 used in the preparation of compounds of formula I or
in the preparation of necessary starting materials are
desirably groups which may readily be split off at a
suitable stage in the reaction sequence, conveniently as
the last stage. It may, however, be convenient in some
instances to employ biologically acceptable, metabolically
labile carboxyl blocking groups such as acyloxymethyl
groups (e.g. pivaloyloxymethyl) and retain these in the
- 42 -
~D
~, . ..
~05999~
final product to g;ve a b~ologically acceptable ester
derivative of a compound of formula I.
Suitable carboxyl blocking groups are well known in
the art, a list of representative blocked carboxyl groups
being included in Belgian Patent No. 783,449. Preferred
blocked carboxyl groups include aryl lower alkoxycarbonyl
groups such as ~-methoxybenzyloxycarbonyl, p-nitro-
benzyloxycarbonyl and diphenylmethoxycarbonyl; lower
alkoxycarbonyl groups such as t-butoxycarbonyl; and lower
haloalkoxycarbonyl groups such as 2,2,2-trichloroethoxy-
carbonyl. The carboxyl blocking group may subsequently
be removed by any of the appropriate methods disclosed
in the lite~ature; thus, for example, acid or base
catalysed hydrolysis is applicable in many cases, as are
enzymically-catalysed hydrolyses.
The antibiotic compounds of the invention, e.g.
compounds of formula I and non-toxic derivatives thereof,
may be formulated for administration in any cnnvenient
way, by analogy with other antibiotics and the inventio.n
therefore includes within its scope pharmaceutical
,
10599~
compositions comprising an antibiotic compound in
- accordancewith the invention adapted for use in human or
veterinary medicine. Such compositions may be presented
for use in conventional manner with the aid of any
necessary pharmaceutical carriers or excipients.
The antibiotic compounds according to the invention
may be formulated for injection and may be presented in
unit dose form in ampoules, or in multi-dose containers with
an added preservative. The compositions may take such
forms as suspensions, solutions, or emulsions in oily or
aqueous vehicles, and may contain fonmulatory age~ts
such as suspending, stabilising and/or dispersing agents.
Alternatively the active ingredient may be in powder form
for reconstitution with a suitable vehicle, e g. sterile,
pyrogen-free water, before use.
The antibiotic compounds may also be presented in a
form suitable for absorption by the gastro-intestinal tract.
Tablets and capsules for oral administration may be in unit
dose presentation form, and may contain conventional excipients
such as binding agents, for example syrup, acacia, gelatin,
sorbitol, tragacanth or polyvinylpyrollidone; fillers,
for example lactose, sugar,
- 44 -
. --
D
-
~os999~
maize-starch, calcium phosphate, sorbitol or glycine
lubricants, for example magnesium stearate, talc,
polyethylene glycol or silica; disintegrants, for
example potato starch; or acceptable wetting agents such
as sodium lauryl sulphate. The tablets may be coated
according to methods well known in the art. Oral liquid
preparation may be in the form of, for example, aqueous
or oily suspensions, solutions, emulsions, syrups or elixirs,
or may be presented as a dry product for reconstitution
with water or other suitable vehicle before use Such
liquid preparation may contain conventional additives
such as suspending agents, for example sorbitol syrup,
methyl cellulose, glucose/sugar syrup, gelatin, hydroxy-
ethylcellulose, carboxymethyl cellulose, aluminium
stearate gel or hydrogenated edible fats; emulsifying
agents, for example lecithin, sorbitan mono-oleate or
acacia; non-aqueous vehicles (which may include edible
oils ),for example almond oil, fractionated coconut oil,
oily esters, propylene glycol or ethyl alcohol; and
preservatives, for example methyl or propyl p-hydroxy-
benzoates or sorbic acid. The antibiotic compounds may
also be formulated as suppositories, e.g. containing
conventional suppository bases such as cocoa butter
~ I _ 45 -
lOS999~
or other glyceride.
Compositions for veterinary medicine may, for
example, be formulated as intramammary preparations in
either long acting or quick-release bases.
The compositions may contain from 0.1% upwards, e.g.
0.1-99%, preferably from 10-60% of the active material,
depending on the method of administration. When the
compositions comprise dosage units, each unit will
preferably contain 50-1500 mg of the active ingredient.
The dosage as empLoyed for adult human treatment will
preferably range from 500 to 5000 mg per day, depending
on the route and frequency of administration, although
in treating Pseudomonas infections higher daily doses
may be required.
The antibiotic compounds according to the invention
may be administered in combination with other therapeutic
agents such as antibiotics, for example penicillins,
tetracyclines or other cephalosporins.
The following examples illustrate the invention. All
temperatures are in ~C. The structure of the products
were verified by p.m.r. spectroscopy (Preparations and
Examples) and i.r. spectroscopy (Examples only).
- 4~ -
. . ~ . .
~OS9g9~
Preparation 1
2-t-Butoxycarbonyimethoxyimino-2-(fur-2-yl)acetic acid
- (syn isomer)
The pH of a mixture of fur-2-ylglyoxylic acid (4.2g),
t-butoxycarbonylmethoxYamine (4.5g) and water (50 ml) was
adjusted to 5.0 with 2N sodium hydroxide solution. The
resulting solution was stirred for 16hours. The pH of the
solution was increased to 7.0, and the solution was washed
twice with ether. The aqueous solution was acidified to
pH 1.8 under ether, and further extracted with ether .
The combined ether extracts were washed (water, saturated
brine), dried , and concentrated to give a solid (7.62g),
which was crystallised frcm carbon tetrachloride to give
the title compound (3.67g, 46%) m.p. 105.1 - 106.2;
AmaX (pH6 phosphate buffer) 277.5 nm ( 16,300).
Preparation 2
2-t-ButoxycarbonvlmethoxYimino-2-(thien-3-vl)acetic acid
(svn isomer)
Thien-3-ylglyoxylic acid and t-butoxycarbonyl-
methoxyamine were reacted as described in Preparation 1 to
give the title compounde m.p. 102.6-104.4 (from carbon
tetrachloride); ~max (pH6 phosphate buffer) 258 nm (~ 13,700).
D! - 47 ~
.....
1 0 59 9 9
Preparation 3
2- RS-a-t-Butoxycarbonylbenz~oxyimino-2-~ur-2-yl),
acetic acid (syn isomer)
a)(i~ A mixture of N-hydroxyphthalimide (24.5g), anhydrous
potassium carbonate (16.5g), t-butyl a-bromophenylacetate
(41g) and dimethylsulphoxide (225 ml~ was stirred for 18
hours and was then poured into water (1.2 litres). The
precipitated solid was filtered off, washed well with water,
dried, and crystallised from industrial methylated spirits
to give N-[a-(t-butoxycarbonyl) benz~loxy] phthalimide
(41g, 78%); m.p. 120.6 - 121.5.
(ii) To a solution of the above oxyphthalimide (40g) in
dichloromethane (500 ml) was added 100% hydrazine hydrate
(11.4 ml). A precipitate was formed immediately. The
mixture was stirred for 1.5 hours, whereafter sufficient
5N ammonium hydroxide solution was added to dissolve the
precipitate. The two layers were separated, and the
aqueous layer was extracted once with methylene chloride.
The combined organic extracts were washed (water,
saturated brine), dried, and concentrated to give t-butyl
a-(aminooxy)phenylacetate (25.0g, 98%) as colourless
crystals, m.p. 48.2 - 49.6~.
-48 _
~ OS9 9 9 ~
b) Fur-2-ylglyoxylic acid and t-butyl -(aminooxy)
phenylacetate were reacted as described in Preparation 1 to
yield the title compound in 42% yield, m.p. 97.9 - 98.9
(from carbon tetrachloride); Ama (pH6 phosphate buffer)
278 nm (e 18,400),
Preparation 4
2-t-Buto carbo lmetho yimi (th ~ l)acetic acid
xy tly _ x
(syn isomer)
To a stirred suspension of sodium hydride (60%
dispersion in oil, 0.96g) in tetrahydrofuran (40 ml) was
added 2-hydroxyimino-2-(thien-2-yl) acetic acid (syn isomer)
(1.71g). The mixture was stirred for 30 minutes, after which
time dimethylsulphoxide (25 ml) was added and stirring was
continued for a further hour. _-Butyl chloroacetate
(1.78g) was added to the mixture, whi~h was stirred for 16
hours and was then poured into water (300 ml). After
being washed twice with ether, the aqueous phase was
acidified to pH 1.7. Extraction with ether and
concentration of the washed (water, saturated brine) and
dried extracts gave a solid (2.71 g) which was crystallised
from carbon tetrachloride to give the title compound
(0.952 g, 33%),m.p. 8803 - 91.3; AmaX (pH 6 phosphate buffer)
- 49 -
~0 5 9 9 9 ~
270.5 and 288.5 nm ( 9,200 and 10,800).
Preparation S
2-(2-t-Butoxycarbonylprop-2-yloxyimino)-2-(fur-2-yl)acetic
acid (syn isomer)
A solution of 2-(fur-2-yl)-2-hydroxyiminoacetic acid
(syn isomer) (14.1g) in dimethyl sulphoxide (lOOml) was added
all at once to a magnetically stirred solution of potassium
t-butoxide (22.4g) in dimethyl sulphoxide (400ml), the
reaction mixture being maintained under an atmosphere of
dry nitrogen. A gel was formed which, on stirring, became
a finely divided, yellow solid. Stirring was continued for
one hour, and then a solution of t-butyl 2-bromo-2-methyl-
propionate (24.0g) in dimethyl sulphoxide (SOml) was added
over one hour to the reaction mixture at room temperature.
After addition was complete, the resulting solution was
stirred for a further hour. The reaction was poured into
ice-water (l.S litres) and acidified under ether (500ml)
to pH 1.8 with concentrated hydrochloric acid. The two
layers were separated, and the aqueous layer was extracted
with more ether. The combined ether extracts were washed
once with water, then extracted with aqueous sodium bicarbonate
solution. The combined alkaline extracts were acidified
_ 50 -
~OS~99~,
under ether to pH 1.8 with concentrated hydrochloric acid,
and the acid solution was extracted further with ether.
The combined ether extracts were washed (water, saturated
brine), dried, and concentrated to a yellow oil, which
crystallised under high vacuum (22.41g, 83%), Ama (EtOH)
272.5nm (~ 15,400).
The above solid (22.4g) was crystallised from carbon
tetrachloride ~25ml) to give the title comPound (16.42g, 61~/o)~
m.p. 72.5-74.2 (73.0).
Preparations 6-20
Method A
The dipotassium salt of 2-(fur-2-yl)-2-hydroxyimino-
acetic acid (svn isomer) was generated under an atmosphere
of dry nltrogen and alkylated with the appropriate halo-t-
butyl ester as described in Preparation 5. The products
were isolated by pouring into water, acidifying, and extracting
in the conventional manner.
Method B
As method A but using a halo-diphenylmethyl ester.
The half esters prepared by these methods are listed
in Table 1.
- 51 -
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Preparation 21
2-( 2-t-Butoxycarbonylprop-2-yloxYimino)-2-(thien-2-vl)
acetic acid (syn isomer)
The title compound was prepared from 2-hydroxyimino-2-(thien-
2-yl)acetic acid (sVn isomer) and t-butyl 2-bromo-2-methyl-
propionate, in a similar manner to that described for
Preparation S, in 78% yield as a colourless oil, and was
characterised as the N-benzyl-2-phenylethylammonium salt,
m p. 201.3-201.9 (from ethanol).
Preparation ~2
2-(2-t-Butoxycarbonylethoxyimino)-2-(fur-2-yl)acetic acid
(syn isomer)
To a mixture of methyl acetohydroximic acid
[CH3.C(:NOH).OCH3] (8.9g) and t-butyl acrylate (12.8g) was
added a solution of potassium t-butoxide (O.lg) in t-butanol
(lml). The mixture was kept at 0 for 6S hours, then washed
with water, dried, and distilled, to give 2-t-butoxycarbonyl-
ethyl methyl acetohydroximate (2;37g, 11%), b.p. 85-87/1.2mm Hg.
To a solution of fur-2-ylglyoxylic acid (1 26g) in
water (SOml) was added 2-t-butoxycarbonylethyl methyl
acetohydroximate (2.15g) and sufficient methanol to give a
homogenous mixture, which was stirred for 30 minutes at pH 1.5.
- 58 -
D
lOS9991
The pH was adjusted to 4.5 ~ith 2N sodium hydroxide solution,
and the mixture was stirred for a further 16 hours, when
reaction was almost complete. Me~hanol was removed under
reduced pressure, the pH of the residue was raised to 7.0,
and the aqueous mixture was washed twice with ether. The
aqueous phase was acidified in the presence of dichloromethane
to pH 1.7, and the phases were separated. The aqueous
phase was extracted twice more with dichloromethane. The
combined dichloromethane extracts were washed with water,
dried, and concentrated to give a fawn solid (1.53g)
(mixture of syn and anti isomers, 85:15) which was
crystallised from carbon tetrachloride to give the title
compound (0.975g, 34%), m.p. 74.7-77.2; ~max (pH6 buffer)
277nm (~ 16,500).
Preparation 23
t-Butyl l-Bromocyclopentanecarboxylate
To a mixture of l-bromocyclopentanecarboxylic acid
(36.99g) and anhydrous ether (35ml) in a 500ml pressure
bottle, containing a magnetic stirrer-bar, was added
concentrated sulphuric acid (3.5ml), followed by precondensed
isobutene (150ml). The bottle was sealed, and stirred at
ambient temperature for 20 hours. The bottle was then opened,
-59 _
,4
~ 059 9 9 ~
excess isobutene was evaporated, and the residue in ether
was washed with aqueous sodium bicarbonate solution and water,
dried, and concentrated. The residue was distilled under
reduced pressure to give the title ester (b.p. 66-74/0.5-
2.0mm) (33.6g~ 70%); Vmax(CHBr3) 1702cm ; T (cDcl3) 7.78,
8.20 (cyclopentane protons) and 8.54 (C(CH3)3).
Preparation 24
Diphenylmethvl a-bromohexanoate
a-Bromohexanoic acid (1.95g) in light petroleum
spirit (25ml, b.p. 40-60) was treated with a stock solution
of diphenyldiazomethane in petroleum spirit (b.p. 40-60)
(ca. 3.8 mmole/lOml) dropwise with stirring until a faint
violet colour persisted. The mixture was stirred for 2 hours
at room temperature, whereupon the solvent was removed in
vacuo. The resulting oil in ethyl acetate was washed with
a saturated aqueous solution of sodium bicarbonate then with
water and dried. Removal of the solvent gave the title ester
(3.0g,90%), AmaX (EtOH) 252, 258, 263.5, 267.5 and 276 nm
( 1650, 1600, 1350, llSO and 850).
- 60 -
~O 59 9 9
Preparations 25-34
-Halo Substituted Carboxy~_c Acid Esters
Method A
The appropriate -halo carboxylic acid was treated
with isobutene and concentrated sulphuric acid in a pressure
bottle at room temperature for 10-40 hours by the method
described in Preparation 23 to give the t-butyl esters listed
in Table 2.
Method B
The appropriate a-halo carboxylic acid in a solvent
(e.g. ether, petroleum, ethyl acetate) waæ treated with a
solution of diphenyldiazomethane until a faint penmanent
colour was obtained. The ester was washed with alkali in
the manner described in Preparation 2;~ to give the
diphenylmethyl esters listed in Table 2,
- 61-
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- 63 -
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Preparation 35
Di-t-butyl 2-Bromo-2-methylmalonate
.
To a stirred suspension of sodium hydride (1.7g,80%
dispersion in oil) in tetrahydrofuran (60 ml) under an
atmosphere of nitrogen was added di-t-butyl methylmalonate
(11.52g). The mixture was stirred at 60-70 for 1.5 hours
to give a clear solution. This solution was cooled to -25,
and to it was rapidly added a solution of bromine (2.6 ml)
in dichloromethane (30ml). The solution was allowed to warm
to ambient temperature, then concentrated. The residue
in ether was washed with water, dried, and fractionally
distilled under reduced pressure to give the title cQmpound
b-p- 78-86/1.0 mm Hg, (7.56g, 49%); vmax(CHBr3) 1730cm
(C02But); I (CDC13) values include 8.05 (s, C(CH3)3)and
8.53 (2s, CH3 and C(CH3)3).
Preparation 36
t-Butyl Ethvl 2-Bromo-2-methylm31onate
The title compound was prepared in a similar manner
to that used for the dibutyl ester in Preparation 3~, in
83% yield, b.p. 64-68/0.03mm Hg.
- 66-
,~
.J
lOS999~
Preparation 37
l-Bromomethylcyclopropane-l-carbox~lic Acid
The bromination of cyclobutane carboxylic acid
led to the corresponding bromoacid together with the title
S acid (ca. 15% yield), m.p. 83-84 (petroleum spirit b.p.
60-80); ~ (d6-DMS0) values 6.25, 8.65 and 8.90.
_~7_
lossas~
EXAMPLE 1
a) (6R ~ eth~l-7-1 2-t-buto~ffcarbonvlmetho~
imino-2-(fur-2 ~ -3-em-4-carboxYlic acid
(s~n isomer~
S Oxalyl chloride (0.45 ml) was added at 50 to a stirred
solution of 2-t-butoxycarbonylmethoxyimino-2-(fur-2-yl)
acetic acid (syn isomer) (1.35 g) in dry dichloromethane
(50 ml) containing triethylamine (0.7ml) and dimethylform-
amide (1 drop). The solution was stirred at 5 for one hour
and was then evaporated to dryness at 5. The residue was
suspended in acetone (SOml) and was added over 30 minutes to
a stirred, ice-cooled solution of (6R,7R)-3-acetoxymethyl-7-
aminoceph-3-em-4-carboxylic acid (1.36g) in water (lOOml)
and acetone (50ml) containing sodium bicarbonate (l.Og). The
reaction mixture was stirred for one hour, whereafter the
acetone was evaporated under reduced pressure. The residue
was acidlfied to pH 1.8, and this mixture was extracted
with ether. The combined extracts were washed (water,
, saturated brine), dried, and evaporated to give the title
compound (2.52g, 96%) as a pale yellow foam, ~a]D + 28.. 5
(c 0.96, DMSO); AmaX (pH6 phosphate buffer) 276.Snm
( ~ 17,900).
-68 -
~05999~
b) (6R.7R)-3-Acetoxymethvl-7-[2-carboxymethoxyimino-2-(fur
2-yl)-~cetamidolceph-3-em-4-carboxylic acid, disodium salt
(sy_ isomer)
A solution of (6R,7R)-3-acetoxymethyl-7-[2-t-butoxy-
carbonylmethoxyimino-2-(fur-2-yl)acetamido]ceph-3-em-4-
carboxylic acid (svn isomer) (1.422g) and anisole (0.25ml) in
trifluoroacetic acid (5ml) was kept at ambient temperature
for 5 minutes. The mixture was concentrated at reduced
pressure, ethyl acetate (lOml) was added, and the mixture
was re-evaporated. The residue was distributed between
ether and sodium bicarbonate solution. The ether layer was
extracted further with sodium bicarbonate solution and the
combined alkaline extracts were acidified to pH 1.8 under
ether. The acid mixture was extracted with ether, and the
combined ether extracts were washed (water, saturated brine),
dried, and evaporated to give the dicarboxylic acid corres-
ponding to the title compound (942 mg, 74Z), ~ (~ - DMSO)
values include O.24 (d, J 8Hz, NH), 4.13 (dd, 7-H), and
5.31 (s, CH2C02H).
This di-acid (9OOmg) in acetone (9ml) was neutralised
with a solution of sodium 2-ethylhexanoate (700mg) in acetone
(5ml). The mixture was stirred for 10 minutes, then the
-69_
~Di
1059991
precipitated solid was filtered off, washed with a littie
acetone~ and dried to give the title compound(807mg, 60%),
[a]D + 15 (c 1.08, DMS0); vma (Nujol) 1766 cm (~-lactam).
Examples 2 - 26
General Procedure for the Preparation_of ~6R!7R)-7-
(2-Aryl-2-carboxy-Rq-oxyiminoacetamido)-3-(substituted)
ceph-3-em ~ c
Salts
~ .
Method A
Following the procedure described in Example 1, a
solution of the appropriate 2-aryl-2-t-butoxycarbonyl-Rq-
oxyiminoacetic acid (syn-isomer) (1 equiv) in methylene
chloride optionally containing a few drops of N,N-dimethyl-
formamide and triethylamine (1 equiv) was treated with
oxalyl chloride (1 equiv) at 0-5 for ca. 1 hour. The
mixture was then evaporated to dryness. The residue was
suspended or dissolved in acetone acd added to a stirred,
ice-cold solution of (6R,7R)-3-acetoxymethyl-7-aminoceph-
3-em-4-carboxylic acid (1-1.2 equiv) in water or a mixture of
acetone and water containing sodium hydrogen carbonate
(2-2.5 equiv). The reaction mixture was stirred for 0.5 -
2.5 hours, allowing the temperature to rise to room
_ 70-
lOS999~
temperature, whereafter the acetone was removed under reduced
pressure. The pH was adjusted to 1.5 - 2.0 and the product
extracted into ethyl acetate ~alternatively ether or methylene
chloride may be used). The organic layer was washed with
water and/or saturated brine, dried and evaporated to give
the corresponding (6R,7R)-3-acetoxymethyl-7-(2-aryl-2-t-
butoxycarbonyl-Rq-oxyiminoacetamido)ceph-3-em-4-carboxylic
acid (syn-isomer) which was characterised by optical rotation
and/or by spectroscopy~
The t-butyl esters were deprotected by treating wit h
trifluoracetic acid containing anisole at room temperature
for at least 5 minutes. The reaction mixture was evaporated
in vacuo and the product isolated by trituration or by
distributing between ethyl acetate (or ether) and an
aqueous solution of sodium hydrogen carbonate, separating
the aqueous extracts, acidifying these extracts under
ethyl acetate and isolating the title dicarboxylic acid
in the usual way. The products are listed in Table 3.
Method B
As Method A except that the appropriate 2-aryl-2-
diphenylmethoxycarbonyl-Rq-oxyiminoacetic acid (syn-isomer)
was used in place of the t-butyl ester. The products are
~ .
lOS999~
listed in Table 3.
Method C
As Method A or B except that the dicarboxylic acid
was converted into its disodium salt by treating a solution
S of theacid in acetone with a solution of sodium 2-ethyl-
hexanoate in acetone. The precipitated disodium salt was
washed and dried. The products are listed in Table 3.
Method D
As Method A except that a (6R,7R)-3(substituted methyl)-
7-aminoceph-3-em-4-carboxylic acid or salt thereof was used
in place of (6R,7R)-3-acetoxymethyl-7-aminoceph-3-em-4-
carboxylic acid. The products are listed in Table 4.
- 72-
`D: --
lOS9991
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- 73 -
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- 74 -
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- 80 -
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- 81
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_ 82 -
~OS999~
Example 2~
(6R,7R)-7-[2-Carboxymethoxyimino-2-(fur-2-yl)-acetamido]-
3-(l-methyltetrazo~5-ylthiomethyl)ceph-3-em-4-carbox-yli-c
acid (syn isomer)
S A solution of 2-t-butoxycarbonylmethoxyimino-2-(fur-
2-yl)acetic acid (syn isomer) (0.97g) in methylene chloride
(20ml) was added dropwise at room temperature over 15 minutes
to a stirred solution of diphenylmethyl (6R,7R)-7-amino-3-
(l-methyltetrazol-5-ylthiomethyl)ceph-3-em-4-carboxylate
(1.484 g) and dicyclohexylcarbodiimide (0.743g) in methylene
chloride (45 ml). After stirring for a further 2 hours the
solvent was removed by evaporation, and the residue was
stirred for 5 minutes with ethyl acetate (50 ml) and filtered.
The filtrate was washed with saturated sodium bicarbonate
solution, diluted with an equal volume of water and then
with brine (25 ml of each), dried and evaporated to a foam
(2.5 g) which was dissolved in benzene and purified by
chromatography on Kieselgel (70 g). Elution with benzene :
ethyl acetate (10 : 1), combination of appropriate fractions
and evaporation to dryness gave a foam (2.05g)
which was dissolved in ethyl acetate and run into
light petroleum to give diphenylmethyl
- 83 -
~059~91
(6R~7R)-7-[2-t-butoxycarbonylmethoxyimino-2-(fur-2-yl)-
acetamidol-3-(l-methyltetrazol-5-ylthiomethyl)ceph-3-em-4-
carbox~late (syn isomer) (2.02 g, 90%) as a white amorphous
solid, [a~D ~ 102 (c 0.99,CHC13); AmaX (EtOH) 278 nm
(~ 19,800).
A solution of this diester (1.93 g) in a mixture
of trifluoroacetic acid (7.7 ml) and anisole (1.9 ml) was
- kept at 0 for 10 minutes and then added to a mixture of
saturated sodium bicarbonate and water (1:3, 850 ml).
iO After stirring for 10 minutes the mixture was washed with
ethyl acetate, covered with more ethyl acetaté (200 ml) and
acidified to pH 2 with concentrated hydrochloric acid.
The organic phase was separated, washed with water and
brine, dried and evaporated to a foam (1.54 g). Thin
i5 layer chromatography suggested that deprotection was
incomplete and the product was retreated with trifluoroacetic
acid (4.3 ml) and anisole (1.1 ml) at 200 for 15 minutes,
whereafter the product was isolated as a foam (1.3 g) as
described above. This foam in ethyl acetate was run into
iight petroleum to give the title dicarboxvlic acid (0.8 g,
59%) as a white amorphous solid, [~D3 ~ 99 (c 1.05,
acetone); Amax (O.lM-pH 6 phosphate buffer) 277 nm
D ` -84 _
~05999~
( 21,900); vm (Nujol) 1780 cm ; ~ (d6-DMS0) values
include 0.19 (d, NH), 4.14 (dd, 7-H), 5.~30 (s, CH2C02H).
Examples 27 - ~7 .
General Procedure for.the Preparation of (6R,7R)-7-[2-
carboxy-Rq-oxyimino-2-~fur-2-yl)acetamidol-3-(substituted)-
ce~h-3-em-4-carboxylic.acids (sYn isomers) usin~
Dicyclohexylcarbodiimide
(i) To a solution of a diphenylmethyl (6R,7R)-7-amino-3- ~
(substituted)ceph-3-em-4-carboxylate (1 equiv) and
dicyclohexylcarbodiimide (1-1.3 equiv) in dry methylene
chloride was added at 0-25o a solution of the appropriate
2-t-butoxycarbonyl-Rq-oxyimino-2-(fur-2-yl)acetic acid
(sYn isomer) (1-1.15 equiv) in dry methylene chloride.
After stirring for 0.5-5.0 hours the dicyclohexylurea was
removed by filtration and the filtrate was evaporated.
The residue in ethyl acetate or methylene chloride was washed
successively with aqueous sodium bicarbonate, water and brine,
_ 85 _
r~,
~Lf,
1059~91
dried and evaporated. The diester was purified by
chromatography on silica or, after decolourisation with
charcoal, by trituration or crystallisation. The product
was characterised by its p.m.r. spectrum and by th;n layer
chromatography.
Where the 7-amino starting material was available as
an acid addition salt the free base was liberated by shaking
with a mixture of ethyl acetate (or methylene chloride) and
an excess of an aqueous solution of sodium bicarbonate.
~.
After washing with water and brine the organic layer was
evaporated to dryness and the free amine,used as described
above.
(ii) Method A. The intermediate diesters so derived were
deprotected by dissolving in a mixture of trifluoracetic
acid (3-10 ml/l g of diester) and anisole (0.8-12 ml/l g
of diester) and left at between 0 and room temperature for
between 5 minutes and 2.5 hours. The mixture was concen-
trated under reduced pressure and added to a mixture of
ethyl acetate or ether and excess aqueous sodium bicarbonate,
and the aqueous layer was washed with ethyl acetate. The
aqueous phase was covered with ethyl acetate and acidified
to pH 1-2 with hydrochloric acid. The organic layer was
- 86 _
~, ,1 i
-'
-
105999~
washed, dried and evaporated to give the required dicarboxylic
acid.
(ii) Method B.
In some cases where treatment with trifluoracetic acid
was insufficient to complete deprotection the intermediate
monoester (usually the t-butoxycarbonyl group was cleaved
more slowly than the diphenylmethoxycarbonyl group) was
retreated with trifluoracetic acid and anisole and the
diacid isolated as described above.
(iii) Method C
The 3-carboxyvinyl derivative described in Example 36
was prepared from a 7-amino derivative in which both
carboxy groups were protected as the diphenylmethyl ester.
The resulting triester was deprotected as in Method B to
provide the required tricarboxylic acid.
The properties of the reaction products are listed
in Table 5.
- 87 -
lOSg991
o ~ zx - ~
~ ) ~ .
n ~ , n
. ~ ~ ~
~ _ _
... ... . I
~æ P ~ n
~æ ~:c ~ `5~ æ
. . ... _.,.. ,,,.. . ~_
~ tP
o o ~; ~o ' '~ a ~.:;;
. oo p,~ , ~ i~
~ _, ~z=(
'' . . . O
~ :IX
Oo ~ rr 3 C ~ ",5~
~ t
~ o 'o I ¦ S ~
.
,~ ~ l--
_ _ ~ ... X D~
~ oo o -
_ . ~3 .
D` -88-
, . .1
105999
. .
a O X
o o , o o X
. ~ ~ ~ .
. ~ . . ... ~ ~
~ ~ g F
~ ~ C
~ ........................ . .
_ 89_
."~ ~,
~OS999~ -
~ ~3
~ . ~X ~
_,~ . C~
r~
U~
.
C~ W :,, . g
_ ... . ....... ............ .... .
~â ~ ~ ! ~ ~ ~
.~,
~, .....
~n
0 3
_ ~
~t
,t ~ P 3
_, ~_ ,
~ ~ ~ ~D
O O ~n o
o o o o
_ . . .
z 3c
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~)
_. ,_ 3
- 90 -
1~
..,.~
~OS999~
.a . ~ _
~ ox
- - _._ ~n
.......... `C C~
.. o
~ ~D ~D ~
.. .
- ........... _ o
- 9 1
,
1059~9~
~_ __ _ _ . . _ ._
. h~ X ~
~ . I ~
~ S :~ o~
, ~, , . _
~o ~o ~ >=z
... .... ,..
. ~
.. ~ ~ .
.
~,
o
~ ~ ~I ;~ R
. O ~ O ~ ~ l- ~ ~1
~ _~ .
_ _ .. _ .
~_
C
h
~h ~h ~ I.n ~ r~ 3
~ It It ~ ~_
- .... ~
n ~
, 0~ ~ ~ 0
Z 3~ ~
~ ~o~ X
! ~ ' ~D 0 00 O I~
_ - -- . . -' 3, ~ _
_ 92 -
D~i
lOS99g~
~3
- ~ ~ ~
o o o o x 9
4 ~ ~
O O ~ ,_ ~~
_ . _
ao ~ I O
~) o .~ ~D Pl
ao ~ O
,~ .. .... .... _ ~0 0
93 -
~D",,7
Examples 38-4 10~9991
General Procedure for the Preparation of (6R,7R)-3-
(substituted)-7-L2-(carbox~,r-9q-oxvimino)-2-~fur~
2-yl)acetamido~-ceph-3-em-4-carboxylic Acids (syn-isomers)
by Treatin~ an Ester of a (6R.7R)-3-(substituted)
7-aminocePh-3-em-4-carboxvlic Acid with an Acid Chloride
~svn-isomer)
A 2-(t-butoxycarbonyl-Rq-oxyimino)-2-(fur-2-yl)acetic
acid (svn-isomer) was converted into its acid chloride as
described for Examples 2-24. A solution of the acid
chloride (1-1.3 equiv) in methylene chloride was added
dropwise at -So to +5O over a period of 10-30 minutes to
a solution of diphenylmethyl (6R,7R)-3-
(substituted)-7-aminoceph-3-em-4-carboxylate (1 equiv) in
IS dry methylene chloride containing propylene oxide (5-20
equiv). The reaction mixture was stirred for ca 1-3
hours at 0 to room temperature and then washed successively
with 2N-hydrochloric acid, aqueous sodium bicarbonate, water
and/or brine. The dried organic layer was evaporated and
the residue purified by trituration, precipitation,
chromatography or crystallisation.
The resulting diphenyl~ethyl (6R,7R)-3-
(substituted)-7-~2-t-butoxycarbonyl-Rq-
oxyimino)-2-(fur-2-yl)acetamido~ceph-3-em-4-carboxylate
(svn isomer) was deprotected as described for the diesters
described in Examples27 -37, Methods A and B. Products
are listed in Table 6.
L D ~` _ 94
1059991
__ . ....
Z X
, 5~ ~3
~ ~z~ @ ~Q ~ ~
D D t~ o ~
~, ^ , -1 æ_\
~ ~.. , a o O
. ~ n~ C~
__~
00 o O o ~ I
_ ~- C ~ I
_ 95- _
LD.,
1059991
. . .
,
_ O ~ O X
. o o o o X _................ . ~
~ ~ ~
~ n O
S~
_ _. _
- 96
~)S9991
Example42
(a) (6R~7R)-3-Benzoyloxvmethvl-7-[2-~2-t-butoxy-
carbonylprop-2-yloxyimino)-2-(fur-2-vl)acetamido~cePh-
3 ~
A suspension of phosphorus pentachloride (313 mg)
in dry dichloromethane (4 ml) at -10 was treated with
N,N-dimethylacetamide (0.7 ml) followed by 2-(2-t-butoxy-
carbonylprop-2-yloxyimino)-2-(fur-2-yl) acetic acid (svn
isomer) (446 mg) portionwise. The resulting solution wa9
stirred at -10 for 30 minutes, treated with ice (ca 1 g)
and stirred at below 0 for 15 minutes. The organic
phase was added dropwise to a solution of (6R,7R)-7-
amino-3-benzoyloxymethylceph-3-em-4-carboxylic acid
(502 mg) in N,N-dimethylacetamide (2 ml) and acetonitrile
(2 ml) containing triethylamine (1.09 ml) at below oo.
The solution was stirred at 0 to 50 for 2 hours, methanol
(0.3 ml) was added, and stirring was continued for
15 minutes. The solution was diluted with dichloromethane
(20 ml) and washed successively with 2N-hydrochloric acid,
water and brine, dried and evaporated to a gum (1.02 g).
A solution of this gum in ethyl acetate (6 ml) was run
dropwise into stirred petroleum ether (b.p. 40-600, 200 ml)
_ 97 _
LD..J
~ 0 59 9 9 1
to give the title acid as a cream powder (769 mg, 83%);
[~D + 260 (c 1.05, acetone); AmaX (pH 6 phosphate buffer)
233.5 nm (~ 19,200) and 274 nm (~ 18,600); ~max (Nujol)
. 1790 cm ~-lactam); ~ (d6-DMS0) values include 0.29
(d, J 8 Hz, NH), 4.03 (dd, J 8 and J 5 Hz, 7-H), 8.50
(s, C(CH3)2) and 8.58 (s, C(CH3)3.
(b~ (6R 7R)-3-Benzoyloxymeth~l-7[2-(2-carboxyprop-2-
yloxvimino~-2-(fur-2-yl)acetamido~ceph-3-em-4-carboxvlic
acid (svn isomer)
A solution of (6R,7R)-3-benzoyloxymethyl-7-[2-
(2-t-butoxycarbonylprop-2-yloxyimino)-2-(fur-2-yl)acetamido]-
ceph-3-em-4-carboxylic acid (syn isomer) (620 mg) in
anisole (0.6 ml) and trifluoroacetic acid (3 ml) was
stirred at 200 for 25 minutes. The solution was partitioned
between ethyl acetate and aqueous sodium bicarbonate
solution and the pH adjusted to pH 8 by addition of solid
sodium bicarbonate. The aqueous phase was separated,
washed with ethyl acetate, covered with ethyl acetate,
and the pH adjusted to pH 1.5 by addition of concentrated
hydrochloric acid. The organic phase was separated,
washed successively with water and brine, dried and
evaporated to an oily foam (584 mg). A solution of this
_ 98 -
~D~
1059991
foam in ethyl acetate was run dropwise into stirred
petroleum ether (b.p. 40-600) to give the title
dicarboxvlic acid as an off-white solid (384 mg, 67%);
[a~D + 30 4 (c 1~0, acetone); AmaX (pH 6 phosphate
buffer) 234 nm (e 19,700) and 273 nm ( 18,450);
vmax (Nujol) 1784 cm (~-lactam); I (d6-DMSO)values
include 0.30 (d, J8 Hz, NH~, 4.07 (dd, J8 and J5Hz, 7-H),
and 8.50 (s, C(CH3)2).
ExamPle 43
Potassium (6R,7R)-7-L2-carboxvmethoxvimino-2-~fur-2~
acetamido~-3-PvridiniummethYl-ceph-3-em-4-carboxylate
(sYn isomer)
A mixture of (6R,7R)-3-acetoxymethyl-7-~2-carboxy-
methoxyimino-2~fur-2-yl)acetamido]ceph-3-em-4-carboxylate
(syn isomer) (3.26 g), potassium thiocyanate (5.25 g),
pyridine (0.72 ml) and water (2 ml) was stirred and heated
for 40 minutes at 800. The cooled reaction mixture was
diluted with water (5 ml) and adsorbed on a column of
XAD-2 resin (500 g). Components of the reaction mixture
were eluted, first with water and then with aqueous
ethanol (1:3) and collected using an automatic fraction
collector. Those fractions having the characteristic
L ~ _ 99 _
1059991
ultraviolet absorption pattern of the required product were
combined and evsporated to dryness in vacuo at <35.
The crude material (600 mg) was crystallised from aqueous
acetone (1:9) to give the title compound (295 mg);
~max (pH 6 phosphate buffer) 261 nm (e 19,000); A
275 nm (e 18,400).
ExamPle 44
Potassium (6R,7R)-7-[2-carboxyprop-2-yloxyimino-2-(fur-2-
yl)-acetamido~-3-pYridiniummethvl-cePh-3-em-4-carboxvlate
(svn isomer)
A mixture of (6R,7R)-3-acetoxymethyl-7-[2-(carboxyprop-
2-yloxYimino)-2-(fur-2-yl)acetamido~ceph-3-em-4-carboxylic
acid (~y~ isomer) (4.0 g), pyridine (4 ml) and water (40
ml) was heated for 1 hour at 800, whereafter the mixture
was allowed to cool. The cooled mixture was diluted with
water (S0 ml) and extracted five times with methylene
chloride (25 ml) and the combined organic extracts were
washed with water. The combined aqueous phases were
evaporated in vacuo at ~35 to ca 50 ml and acidified to
pH 2 with 2N-hydrochloric acid. The precipitated solid
was removed by filtration, the filtrate was adjusted to
- 100 -
D~
lOS999~ . .
pH 6.5 with potassium bicarbonate and the solution was
concentrated in vacuo at ~35 to ca. 40 ml. The product
was purified on a column of XAD-2 resin (500 g), elution
being effected with water and then aqueous ethanol (1:3).
Fractions having the characteristic ultraviolet absorption
of the product were combined and evaporated to dryness in
va~uo at~ 35O to give the itle compound (880 mg),Amax
(H20) 261 and 277 nm (~ 17,000 and 16,950).
Example 45
Sodium (6R,7R)-7~[2-~carboxyprop-2-yloxyimino
acet ~ diniummethylceph-3-em-4-carboxvlate
(syn ~
A mixture of sodium iodide (50.0 g), water (15.5 ml)
and pyridine (14 ml) was heated to 800 and stirred
vigorously during the addition over a period of ca 10
minutes of (6R,7R)-3-acetoxymethyl-7-~2-(carboxyprop-2-
yloxyimino)-2-(fur-2-yl)acetamido]ceph-3-em-4-carboxylate
(~y~ isomer) (14.4 g). The mixture was stirred at 800
for a total of 55 minutes and was then cooled and diluted
to ca 400 ml with water. 0.1 N-Sodium hydroxide was
added to adjust the pH to ca 6.5 and the solution was
concentrated under reduced pressure at ~40 to a volume
_ 101 _
D ~!
~0 59 9 9 ~
of ca 100 ml. The resulting solution was diluted to
ca 400 ml with water, methyl isobutyl ketone (0.3 ml)
was added and the stirred solution was acidified with
2N-hydrochloric acid (15 ml) to achieve a pH of 1-2.
The solid was collected, washed with water and discarded.
The filtrate and washings were treated with more 2N-
hydrochloric acid (ca 10 ml) and extracted wLth ethyl
acetate, the organic layer being re-extracted with a
small volume of water. The aqueous phase was adjusted
to pH 6 with lN-sodium hydroxide (ca 43 ml) and evaporated
under reduced pressure at < 40 to a volume of ca 175 ml.
This solution was applied to a column of XAD-2 resin
(700 g, 42 cm x 5.5 cm) that had previously been washed
with water (2 litres). The column was eluted with water,
the fractions being collected automatically and monitored
by U.V. spectroscopy. When the inorganic salts and
some impurities had been removed the eluant was changed
to a mixture of ethanol and water (1:4). The fractions
having the characteristic U.V. absorption of the product
were combined, concentrated under reduced pressure at ~ 40O
then freeze-dried. The product was dried over phosphorus
pentoxide in vacuo giving the title salt (4.10 g);
_ 102 _
~7
~h i-'
1 059 99 1
[]D + 10.5O (c 1.00, H2O); AmaX (pH 6 ~uffer) 261.5 and
278.5 nm (E 20,100; 19,200); vm (Nujol) 1770 cm 1
(~-lactam); ~ (D20, 100 MHz) values include 1.03, 1.43,
1.91 (pyridinium protons), 4.12 (dd, 7-H) and 8.50
(s, C(CH3)2).
Examples 46-50
In the manner of Example 45 the acetoxy group of
(6R,7R)-3-acetoxymethyl-7-[2-(carboxy-R9-oxyimino)-2-
(fur-2-yl)acetamido]ceph-3-em-4-carboxylic acids (sYn
isomers) were displaced by treatment with pyridine or a
substituted pyridine in aqueous sodium iodide solution
at 80~ for 45-60 minutes. The products were purified
as the sodium salts by XAD-2 chromatography and their
physical properties are summarised in Table 7.
-103 -
1059991
.~ ..................................... 2:~ ~;
O X
~S n n =
_ ~ ~
~ o3 ~
8 C ~ ~ ~
. j o ~ ~" o. ~,
. R -- J
~ ~Z-~
_ . O C~
O O O ao O ~ X
~ n ~ ~3 ~ O
_._. ~ ~.. .. ~
5~__ '!~
. ~ O
_ ~ oOo ~ C~
. ~ ~
. o' -~ ~
~, . ,_ 3 .
't
,~ - 104 -
'D'l ~
lOS9~9~
~ .... .. ~ .
X
..
-- .1 1
~ X,~
,. ~
~ n 5~ O
~ _ ~
. .
_ 1 05 -
,~ .;
.
105999~
. .. _ .
_ ~., .. . Z~
' ~:
' ~ ' ~ .
r ~
O aO~ ~3
. . ~
_...... , ...... .... _
oO .
..... .~.. . ~
_ . . ... ~ _ .
- lo~ -
~059991
. ._ l
- ~P `C ~
~ IPO 11
- 107-
iD
~S9991
Example 51
(6R.7R)-7-[2-(2-Carboxvprop-2-yloxyimino)-2-(fur-2-yl)-
acetamidol-3-pyridaziniummethylceph-3-em-4-carboxylic acid
trifluoroacetate (syn_isomer)
5 ` (a) A suspension of diphenylmethyl (lS,6R,7R)-3-bromo-
methyl-7-[2-(2-t-butoxycarbonylprop-2-yloxyimino)-2-(fur-
2-yl)ace~amido~ceph-3-em-4-carboxylat~ l-oxide (svn
isomer) (1.51 g) in N,N-dimethylformamide (1 ml) was
treated with pyridazine (400 mg). The mixture was
stirred for 2 hours at 25o to give a clear solution, which
was then diluted with ether (50 ml, added slowly with
stirring). The resulting precipitate was filtered off,
washed with ether and dried to give diphenYlmethvl
(lS,6RL7R)-7-~2-(2-t-butoxvcarbonvlprop-2-vloxvimino)-2-
~fur-2-yl)acet mido]-3-pyridaziniummethvlceph-3-em-4-
carboxylate l-oxide bromide (sYn isomer)as a pink powder
(1.59 g, 94%); []D + 13 (c 1.07, DMSO); AmaX (EtOH)
277 nm (~ 21,200); vmax (Nujol) 1790 cm (~-lactam);
~ (d6-DMSO) values include 1.21 (d, J 8Hz, NH), 3.76
(dd, J 4 and 8Hz, 7-H), 8.51 (~, C(CH3)2) and 8-61 (s,
C(CH3)3)-
- 108 -
1059~91
(b) The product of (a) above ~1.49 g) in N,N-dimethyl-
formamide (5 ml) at -10 was treated with potassium
iodide (1.33 g) and then with acetyl chloride (0.28 ml).
The mixture was stirred for 1 hour while the temperature
slowly rose to oo, and was then added dropwise to a
stirred solution of sodium metabisulphite (1 g) in water
(50 ml). The resulting suspension was stirred for
10 minutes and then the solid material was filtered off,
washed with water and dried over phosphorus pentoxide
to give a light brown powder (1.28 g). This material,
in acetone: ethanol = 9: 1 (20 ml), was passed down
a column of Deacidite FF resin (trifluoroacetate form,
15 cm x 2.5 cm i.d.) which was eluted with the same
solvent mixture. Eluant fractions containing ultra-
violet light absorbing material were combined and
evaporated, and the residue was triturated with ether
to give diphenylmethyl (6R,7R)-7-[2-(2-t-butoxycarbonyl-
prop-2-yloxyimino)-2-(fuE-2-yl)acetamido]-3-pyridazinium-
_ _ ... .....
methylceph-3-em-4-carboxylate trifluoroacetaée ~syn
isomer), (1.24 g, 82%); [a~D -200 (c 0.76, DMSO);
AmaX (EtOH) 278 nm (~ 18,300); vmax (Nuj ol) 1780 cm
(d6-DMSO) values include 0.30 (d, J8Hz, llH), 3.95
- 109 -
~OS5~99~
(dd, J 5 and 8 Hz, 7-H), 8.55 (s, C(~H3)2) and 8.59
(s, C(CH3)3).
(c) The product of (b) above (1.13 g), mixed with
anisole (1.5 ml), was treated with trifluoroacetic acid
(6 ml) at 50 for 5 minutes, and then at 200 for 55
minute`s. The solution was evaporated in vacuo, the
residue was stirred with ethyl acetate, and the
evaporation repeated. The resulting gum was triturated
with ether to give the crude product as a pale brown
solid, which was filtered off, washed with ether and dried.
This was extracted with water (3 x 150 ml); the extracts
were filtered, washed with ethyl acetate and then ether,
and finally freeze-dried. The combined residues were
triturated with ether to give the title salt as a
white powder (586 mg, 72%); [a]D + 480 (c 0.98, DMS0);
A (pH 6 phosphate buffer) 277 nm (~ 18,100); v
(Nujol) 1776 cm (~-lactam); ~ (d6-DMS0) 0.37 (d J 8 Hz,
NH), 4~09 (dd, J 5 and 8 Hz, 7-H) and 8.53 (s, C(CH3)2).
ExamPles 52-57
The trifluorDacetatesalts listed in Table 8 were
prepared by reacting the 3-bromomethyl ester (see below)
with the apPropriate tertiary base (or quaternary mercaptan
- 110 -
1059991
for Example 54), reducing the sulphoxide and removing
both protecting groups in a similar manner to that
described in Example 5L The starting material was
prepared as follows:-
S A solution of phosphorus pentachloride (5.20 g)
in dry dichloromethane (60 ml) at -10 was treated with
N,N-dimethylacetamide (12 ml), and then with 2-(2-t-
butoxycarbonylprop-2-yloxyimino)-2-(fur-2-yl)acetic
acid (sYn isomer) (6.43 g) added portionwise. The
solution was stirred at -10 for lS minutes and then
ice (14 g) was slowly added and the temperat~re allowed
to rise to 0 over 10 minutes. The organic layer was
separated and added dropwise to a suspension of diphenyl-
methyl (15,6R,7R)-7-amino-3-bromomethylceph-3-em-4-
carboxylate l-oxide hydrobromide (10.62 g) in dichloro-
methane (80 ml) containing propylene oxide (lS ml) at 0.
The mixture was stirred for 1 hour during which time the
temperature rose to 20 and the suspension cleared. The
resulting yellow solution was washed with 2.5% aqueous
sodium bicarbonate solution (S0 ml) and then 2N-hydro-
chloric acid (50 ml), whereafter the solution was dried
and evaporated to a yellow oil. This material, in ethyl
- 111 -
....
:
. ~059991
acetate (20 ml),was added dropwise to stirred petrol
(b.p. 40 - 600) to give a gummy precipitate. The
supernatant was decanted off and the gum chromatographed
on a column of Kieselgel, which was eluted with
dichloromethane containing from 0 to 10% acetone.
Eluant fractions containing the main product were
ccmbined and evaporated to a foam. Trituration with
cyclohexane gave diphenylmethyl (lS,6R,7R)-3-bromomethYl-
7-[2-(2-t-butoxvcarbonylprop-2-yloxyimino)-2-(fur-2-yl)-
acetamido]ceph-3-em-4-carboxvlate l-oxide (syn isomer)
as a pale yellow microcrystalline powder (13.61 g, 90%);
[~D ~ 220 (c 1.0, DMSO); Am x (EtOH) 281 nm (~ 22,200);
Vmax (C Br3) 1800 cm (~-lactam); ~ (d6 DMSO) values
include 1.26 (d, J 8 Hz, NH), 3.86 (dd, J 4 and 8 Hz,
7-H), 8.51 (s, C(CH3)2) and 8.61 (s, C(CH3)3).
_ 112 -
105999
n
~ nf ~ ~
. ~ ~ ~ ~
~ -
1~ ~
~ ~~ ~ ~
i.. ~ ~d
~o ~ ~ z
~ t
r~ U)
. ~ ~ I_
~D O ID O ~ O ~
o~ o c~
o o ~ ~J 0~._. ~
~n ~n ~_O~ '
a~ ~ æ
8X
~t~5
~ o~ ~ ~
r~ ~_
O O O ~ O ~ . .~
o o o o o
- ~ ~o ~ /
o ~ J o - ~ ~
- ~ ~ ~- -- ~
,,Ds ~ 113-
~OSg991
- --~ ~
e ~ n Z x
~ - _ ~
o o o ' o x e o~
~h
'C
o ~ It
O ............ ~ .__ O
~n ao oo oo oo :~ ~
G ~ n ~ ~ o ¦
- 114 -
, .
lOS9~9~
. r . _ r. .. l-3
~ ZX i~i
S C~ ~
r ~ ~ I
O;
.
~D 0
. â~
~ n ~
. _ ... ...,... ___ _
'' OD 0~ ~
o ~0 oO
, ,, . ", ,, ,,,.. , ................. ................. .. _ ., _
- 1'1 S
.
~05999~
...... __ ~_
'' ~ O o
po, ' ... . . .. _ _ ,t '~'
D
00 00 ___ . N
- 116 -
D~
lOS9~9~
Example 58
-
(6R,7R)-3-(Benzotriazol-l-ylmethyl)-7-~2-(2-carboxvproP-
2-yloxyimino~-2-(fur-2-yl)acetamido]ceph-3-em-4-
carboxvlic acid (SYn isomer)
Diphenylmethyl (lS,6R,7R)-3-bromomethyl-7-[2-~2-t-
butoxycarbonylprop-2-yloxyimino)-2-(fur-2-yl)acetamido]-
ceph-3-em-4-carboxylate l-oxide (svn isomer) (1.51 g) in
N,N-dimethylformamide (3 ml) was stirred with benzo-
triazole ~480 mg) for 4 days. The solution was diluted
with dichloromethane and then washed twice with 2N-
hydrochloric acid; the solution was then dried and
evaporated, and the main product was isolated from the
residue by column chromatography on Kieselgel, with
chloroform containing 0 to 10% v/v acetone for elution.
This material (700 mg) in N,N-dimethylformamide (2 ml)
with potassium iodide (665 mg) at -10 was treAted with
acetyl chloride (0.14 ml). The suspension was stirred
for 1.25 hours and allowed to warm slowly to 0, and was
then added dropwise to water (40 ml) containing sodium
metabisulphite (0.5 g). The precipitate was filtered
off, washed with water, dried, and purified by chroma-
tography on Kieselgel, eluting with dichloromethane
.- _ 117 -
~; .
10~999~
containing from 0 to 3% v/v acetone.
The diester so obtained (520 mg), together with
anisole (0.5 ml), was treated with trifluoroacetic acid
(2 ml) at 25o for 1 hour. The solution was then added
dropwise with stirring to sat~rated aqueous sodium
bicarbonate (50 ml) and ice (25 g). The mixture was
stirred, whereafter ethyl acetate was added. The
aqueous layer was separated and acidified unde~ ethyl
acetate to pH 2. The organic layer was separated, and
the aqueous layer extracted with more ethyl acetate.
The combined extracts were dried and concentrated to an
oil, which was added dropwise to stirred petrol (b.p.
40 - 600). The white precipitate was filtered off,
washed with petrol and dried to give th~ title dicarboxYlic
acid as a white powder (350 mg, 31%); [~D ~ 37
); ~max (pH 6 phosphate buffer) 269 nm
(e 23,600); vmax (Nujolj 1780 cm I (~-lactam);
(d6-DMS0) values include 0.40 (d, J 8 Hz, NH), 4.11
(dd, J 5 and 8 Hz,7-H) and 8.53 (s, C(CH3)2).
Example 59
The compound listed in Table 9 was prepared from
the appropriate nucleophile using the method of Example 58.
- 118 -
_ ,,
. 10599gl
119 -
~059~9~
-~ ~
_.
- 1 20 -
~ '
~05999~
Example 60
(lS,6R~7R)-3-Acetoxvmethvl-7-[2-(2-carboxvprop-2-Yloxyimino)-
2-(fur-2-yl)acetamido~ceph-3-em-4-carboxylic acid l-oxide
(syn isomer)
(a) A solution of (6R,7R)-3-acetoxymethyl-7-[2-(2-
carboxyprop-2 yloxymino)-2-(fur-2-yl)acetamido]ceph-3-
em-4-carboxylic acid, di-t-butyl ester (syn isomer)
(1.21 g) in pyridine (25 ml) and water (1 ml) at -45 was
treated with t-butyl hypochlorite (0.3 ml) with vigorous
stirring. After 2 minutes 2N-sulphurous acid (1 ml)
was added to the solution and the mixture was immediately
poured into aqueous phosphoric acid (100 ml, 20% v/v).
The aqueous solution was extracted with ethyl acetate
and the organic extracts were washed with 0.5N-hydrochloric
lS acid (50 ml), aqueous sodium bicarbonate solution (50 ml)
and water, then dried and concentrated in vacuo. The
crude product was chromatographed on silica gel
preparative plates, using ethyl acetate : petroleum ether
(b.p. 60-800) (4 : 1) as eluant. The slower running
band was extracted with ethyl acetate to yield the
di-t-butyl ester of the title compound (505 mg); vm
(Nujol) 1798 (~-lactam), 1738, 1727, 1715 (acetate and
- 121 -
,D~'
J~
1059991
C02.tBu), 1680 and 1542 cm (CONH); ~ values (DMSO-d6)
include 0.28 (d, J 8 Hz, NH), 4.19 (dd, J 5 and 8 Hz,
7-H), 5.02 (d, J S Hz, 6-H), 5.71 and 6.38 (ABq, J 18 Hz,
2-H).
The di-t-butyl ester (0.38 g) in trifluoroacetic
acid (5 ml, containing a few drops of anisole) was
stirred at room temperature for 15 minutes. The solution
was concentrated in vacuo to a red oil, diluted with
ethyl acetate (2 ml) and added dropwise to vigorously
stirred petroleum ether (b.p. 60-80) (50 ml). The
deposited solid was collected, washed with ether (S ml)
and dried to yield the title acid (185 mg, 60%); AmaX
(ethanol) 276 nm (e 16,600); vmax (Nujol) 1790 (~-lactam),
1730 (acetate), 1720 (C02H), 1680 and 1523 (CONH) and
1040 cm 1 (S ~~O); ~ values (DMSO-d6) include 0.21
(d, J 8 Hz, NH), 4.17 (dd, J 5 and 8 Hz, 7-H), 5.01
(d, J 5 Hz, 6-H), 5.71 and 6.32 (ABq, J 18 Hz, 2-H),
8.49 (s, C(CH3)2).
The starting material for the above oxidation process
was prepared as follows:
A solution of t-butyl (6R,7R)-7-amino-3-acetoxy-
methylceph-3-em-4-carboxylate (1.05 g) in dry dichloro-
r ~ ~ _ 12 2
1059991
methane (10 ml) was added to a solution of 2-(2-t-butoxy-
carbonylprop-2-yloxyimino)-2-(fur-2-yl)acetic acid
(~y~ isomer) (0.99 g) and dicyclohexylcarbodiimide
(0.69 g) in dry dichloromethane (10 ml), and the mixture
was stirred at room temperature for 1 hour. The
solution was filtered and concentrated in vacuo. The
crude product was passed down a column of silica gel
(MFC, 100-200 mesh, 2 x 20 cm) using ethyl acetate :
petroleum ether (b.p. 60-80)(1 : 1) as èluant.
Combination of appropriate fractions as determined by
thin layer chromatography yielded ~6R.7R)-3-acetoxymethyl-
7-[2-(2-carboxvprop-2-vloxYimino)-2-(fur-2-Yl)acetamidol-
ceph-3-em-4-carboxylic acid. di-t-butyl ester (sYn isomer)
(1-29 g); vmax (C B r3) 1776 (~-lactam), 1725, 1712
(acetate and C~2.tB~ 1678 and 1512 cm 1 (CONH);
(CDC13) values include 1.90 (d, J 8 Hz, NH), 4.08
(dd, J 5 and 8 Hz, 7-H) and 4.98 (d, J 5 Hz, 6-H).
Example A
This example illustrates the formulation of a
pharmaceutical composition.
Drv Powder for Iniection
Sterile (6R,7R)-3-acetoxymethyl-7-[2-(1-carboxy-
_ 123 -
LP~ f
... . .
~OS9991
cyclopent-l-yloxyimino)-2-(fur-2-yl)acetamido~ceph-3-em-
4-carboxylate disodium salt (syn isomer) is filled into
glass vials, the claimed contents of each container being
500 mg or 1.00 g of the antibiotic as desired. Filling
is carried out aseptically under a blanket of nitrogen.
The vials are closed using rubber discs or plugs held in
position by aluminium sealing rings, thereby preventing
gaseous exchange or ingress of microorganisms. The
product would be intended for reconstitution with
Water for Injections or other suitable sterile vehicle
shortly before administration.
~ ~ - 124 -
