Note: Descriptions are shown in the official language in which they were submitted.
1~3~2~3~
- This invention is concerned with cephalosporin
compounds possessing valuable antibiotic propert;es.
The cephalosporin compounds in this specification
are named with reference to "cepham" after J-~Amer_Chem.
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 pathogen:ic bacteria in
human beings and animals, and are especially useful in
the treatment of diseases caused by bacteria which are
resistant to other antibiotics such as penicillin com-
- pounds, and in the treatment of penicillin-sensitive
patients. In many instances it is desirable to employ a
cephalosporin antibiotic 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.
Thus, for example, in our British Patent Specifica-
tion No. 1,399,086, we describe a novel class of cephalo-
sporin antibioticscontain ~g a 7~-(a-etherified oxyimino)-
acylamido group, the oxyimino group having the ~y~ config-
uration. This class of antibiotic rompounds is character-
ised by high antibacterial activlty against a range of
'~
., ~ . .
~3~28~ 2
gram-positive and gram-negative organisms coupleA with
particularly high stability to ~-lactamases produced by
various gram-negative organisms.
The discovery of this class of compounds has
stimulated further research in the same area in attempts
to find compounds which have improved properties, for
example against particular classes of organisms especially
gram-negative organisms.
In our British Patent Specification No. 1,496,757,
we describe cephalosporin antibiotics containing a 7~-
acylamido group of the formula
R.C.CO.NH-
RA (A)
0~ H2)m C (CH2)nCOOH
R
(wherein R is a thienyl or furyl group; RA and R may
vary widely and may, for example, be Cl 4 alkyl groups or
together with the carbon atom to which they are attached
form a C3 7 cycloalkylidene group, and m and n are each O
- 20 or 1 such that the sum of m and n is O or 1), the
compounds being Q isomers or mixtures of ~y~ and anti
isomers containing at least 90% of the ~y~ isomer. The
3-position of the cephalosporin molecule may be unsub-
stituted or may contain one of a wide variety of possib]e
substituents These compounds have been found to have
particularly good activity against gram-negative organisms.
Other compounds of similar structure have been
developed from these compounds in further attempts to find
antibiotics having improved broad spectrum antibiotic
2~3~
activity and/or high activity against gram-negative organisms. Such develop-
ments have involved variations in not ~nly the 7~-acylamido group of formula (A)
but also the introduction of particular groups in the 3-position of the cephalo
sporin molecule.
mus, for example, South African Patent Specification 78/1870 dis-
closes cephalosporin antibiotics wherein the 7~-acylamido side chain is inter
alia a 2-(2-aminothiazol-4-yl)-2-(optionally substituted alkoxyimuno)-acetamido
group and the 3-position may be substituted, for example, by the group -CH2Y in
which Y represents the residue of a nucleophile, the Specification c~ntaining
numerous examples of such nucleophiles, including nitrogen nucleophiles. The
Specification contains, among numerous other examples, references to ocmpounds
in which the above-mentioned optionally substituted alkoxyimino group is a
carboxyalkoxyimino or carboxycycloaLkoxyimino group. South African Patent
Specification 78/2168 discloses in broad terms sulphoxide compounds correspond-
iny to the sulphides described in the last-mentioned Specification.
FurthermDre, Belgian Patent Specification No. 836,813 discloses
oe phalosporin compounds wherein the group R in formula (A) above may be replaced
by, for example, 2-aminothiazol-4-yl, and the oxyimino g~oup is a hydroxyimino
or blocked hydroxyimino group, eOg. a methoxyim m o group. In such oompounds,
the 3-position of the oephalosporin mDlecule is substituted by a methyl group
which may itself be optionally substituted by any of
, ~ . ,,
.
3~
-- 4 --
a large number of residues of nucleophilic compounds
therein described. In the above-mentioned Specification
no antibiotic activity is ascribed to such compounds which
are only mentioned as intermediates for the preparation
of antibiotics described in that Specification~
~36~:81
- 5 -
We have now discove~ed that by an appropriate
selection of a small number of particular groups at the
7~-position in combination with a 3-alkyl-1,2,3-tri-
azolium-l-ylmethyl group at the 3-position, cephalosporin
compounds having particularly advantageous activity
(described in more detail below) against a wide range
of commonly encountered pathogenic organisms may be
obtained.
The present invention provides cephalosporin anti-
biotics of the general formula:
NH2
H H
S N
.CO,NH , ~ S
N Ra ~ -- N ~ C~l2N ~ N -
O.C.COOH
Ib COO (I)
(wherein R and R , which may be the same or different,
each represent a Cl 4 alkyl group (preferably a straight
chain alkyl group, i.e. a methyl, ethyl9 n-propyl or n-
butyl group and particularly a methyl or ethyl group) or
Ra and R together with the carbon atom to which they are
attached form a C3 7 cycloalkylidene group, preferably a
C3 5 cycloalkylidene group; and Rl represents a Cl 4 all;yl
group, e.g. a methyl group)and non-toxic salts and non-
toxic metabolically labile esters thereof.
The compounds according to the invention are syn
isomers. The syn isomeric form is defined by the
configuration of the group
~,~
.
lL3~;~ 80
~ 6 --
a
. .1 .
OoC~COOH
Ib
with respect to the carboxamido groupO In thls Speci~i-
cation the ~ configuration is denoted structurally as
NH2
\ - ~ C.CO.NH
N Ra
\ o.c.COOH
Rb
It will be understood that since ~he compounds
according to the invention are geometric isomers, some
admixture with the corresponding anti isomer may occur.
The invention also includes within its scope the
solvates (especially the hydrates~ of the compounds of
formula (I). It also includes within its scope salts of
esters of compounds of formula (I)G
The compounds according to the present invPntion
may exist in tautomeric forms (for example in respect of
the 2-aminothiazolyl group) and it will be understood that
such tautomeric forms, e.g. the 2-iminothiazolinyl form,
are included within the scope of the inventionc Moreover,
the compounds of ormula ~I) depicted above may also exist
in alternative zwitterionic forms, for example wherein the
4-carboxyl group is pxotonated and the carboxyl group in
the 7-side chain is deprotonated. These alternative
forms, as well as mixtures of zwitterionic forms, are
~: .
~9~3~2~3
-- 7
included within the scope of the present inventlon~
It will also be appreciated that when Ra and Rb
in the above formula represent different Cl 4 alkyl
; groups, the carbon atom to which they are attached will
comprise a centre of asymmetry. Such compounds are
diastereoisomeric and the present invention embraces
individual diastereoisomers of these compounds as well
as mixtures thereof.
The compounds according to the invention exhibit
broad spectrum antibiotic activity. Against gram-nega
tive organisms the activlty is unusually high. This ,high
- activity extends to many ~-lactamase-producing gram-
negative strains. The compounds also possess high
stability to ~-lactamases produced by a range of gram-
negative and gram-positive organisms.
Compaunds according to the invention have been
found to exhibit unusually high activity against strains
of Pseudomonas organisms, e.g. strains of Pseudomonas
aeru inosa as well as high activity against various members
of the Enterobacteriaceae (e.g. strains of Escherichia
coli, Klebsiella_pneumoniae, Salmonella typhimurium,
Shigella sonnei, Enterobacter cloacae, Serratia marcescens,
Providence species, Proteus mirabilis, and especially
.. ..._ _ .
indole-positive Proteus organisms such as Proteus vulgaris
and Proteus mor~anii) and strains of Haemophilus
influenzae.
The antibiotic properties of the compounds accord-
ing to the invention compare very favourably with those of
~ ~ 3~ ~ ~0 ~ 8 -
the aminoglycosides such as amikacin or gentamicin. In
particular, this applies to their activity against strains
of various Pseudomonas organisms which are not susceptible
to the majority of existing commercially available anti-
biotic compounds. Unlike the aminoglycosides, cephalo-
sporin antibiotics normally exhibit low toxicity in man.
The use of aminoglycosides in human therapy tends to be
limited or complicated by the relatively high toxicity
of these antibiotics. The cephalosporin antibiotics of
the present invention thus possess potentially great
advantages over the aminoglycosides.
Non-toxic salt derivatives which may be ormed by
reaction o either or both of the carboxyl groups present
in the compounds of general formula (I) include inorganic
base salts such as alkali met~l salts ~e.g. sodium and
potassium salts) and alkaline earth metal salts (e.g.
calcium salts); amino acid salts (e,g. lysine and
arginine salts); organic base salts (e.g. procaine,
phenylethylbenzylamine, dibenzylethylenediamine, ethanol-
amine, diethanolamine and N-methylglycosamine salts).
Other non-toxic salt derivatives include acid addition
salts, e.g. formed with hydrochloric, hydrobromicS
sulphuric, nitric, phosphoric, formiG and trifluoroacetic
acids. The salts may also be in the form o resinates
formed with, for example, a polystyrene resin or cross-
linked polystyrene divinylbenzene copolymer resin con-
taining amino or quaternary amino groups or sulphonic
acid groups, or with a resin containing carboxyl groups,
e.g. a polyacrylic acid resin. Soluble base salts (e~g.
' ~ :
,
~3~
alkali metal salts such as the sodium salt~ of compounds
of formula (I~ may be used in therapeutic applications
because of the rapid distribution o~ such salts in the
body upon administration. Where, however, insoluble
salts of compounds (I~ are desired in a particular appli-
cation, e.g. for use in depot preparations, such salts
may be formed in conventional manner, for example with
appropriate organic amines.
These and other salt derivatives such as the salts
with toluene-p~sulphonic and methanesulphonic acids may
be employed as intermediates in the preparation and/or
purification of the present compounds of formula (I), for
example in the processes described below.
Non-toxic metabolically labile ester derivatives
which may be formed by esterification of either or both
carboxyl groups in the parent compound of formula (I)
include acyloxyalkyl esters e.g. lower alkanoyloxy-methyl
or -ethyl esters such as acetoxy-methyl or -ethyl or
pivaloyloxymethyl esters. In addition to the above ester
derivatives, the present invention inclu~es within its
scope compounds of formula (I) in the form of other
physiologically acceptable equivalents, i.e. physiologic-
ally acceptable compounds which, like the metabolically
labile esters are converted _ vivo into the parent anti-
biotic compound of formula (I).
Preferred compounds accoxding to the presentinvention include those compounds of formula (I) wherein
R represents a methyl group. Preference is also
expressed for those compounds wherein Ra and Rb both repre-
sent methyl groups or together with the carbon atom to
~13~3Z~3~ 10-
which they are attached form a cyclobutylidene group.
Particularly preferred compounds according to the lnvention
include the following compounds of formula (I) and their
non toxic salts and non-toxic metabolically labile esters:-
(~R,7R~7~E(Z~2-(2-~minothiazol-4-yl)-2~(2-carboxyprop-2-
oxyimino)acetamido]-3-(3-methyl-1,2,3-triazolium l-yl)-
methyl-ceph-3-em-4-carboxyl~te; and (6R,7R)-7-~(Z)-2-(2-
aminothiazol-4-yl)-2-(1-carboxycyclobut-1-oxyimino)acetamido~-
: 3-(3-methyl-172~3-triazolium-l-yl)methyl-ceph-3-em-4-
carboxylate~ .
Other compounds according to the present invention
include those for example wherein the groups Ra, Rb and
are as follows:-
Ra Rb . ' 1 --
15 a) Alkyl roups
-CH3 2 5 CH3
2 5 2 5 -CH3
-CH3 -CH3 -C2H5
-CH3 C2H5 -C2H5
C2H5 C2H5 -C2H5
b)
.' (Ra _ ~ _ Rb~
cyclopropylidene ~CH3
cyclopentylidene -CH3
cyclopropylidene C2H5
cyclobutylidene C2H5
cyclopentylidene -C2H5
. . . . .
. .
~3~3Z1~9
The compounds of formula (I) may be used fox treat-
ing a variety of diseases caused by pathogenic bacteria in
human beings and animals, such as respiratory tract
- infections and urinary tract infections.
According to another embodiment of the invention we
provide a process for the preparation of an antibiotic
compound of general formula (I) as hereinbefore defined or
a non-toxic salt or non-toxic metabolically labile ester
thereof which comprises (A) acylating a compound of the
: 10 formula
H H
o ~L CH211~N - Rl
COO~ (II)
[wherein R is as defined above; B is ~ S or
: ~S ~3 O (a- or ~-); and the dotted line bridging the 2-,
3- and 4-positions indicates that the compound is a ceph-
2-em or ceph 3~em compound] or a salt, e.g. an acid addi-
tion salt (formed with, for example, a mineral acid such
as hydrochloric, hydrobromic, sulphuric, nitric or phos-
phoric acid or an organic acid such as methanesulphonic
or toluene-p-sulphonic acid) or an N-silyl derivative
thereof, or a corresponding compound having a group of
formula ~ COOR at the 4-position [where R is a hydrogen
atom or a carboxyl blocking group, e.g. the residue of an
estex-forming aliphatic or araliphatic alcohol or an
~ ester-forming phenol, silanol or stannanol (the said
alcohol, phenol, silanol or stannanol preferably
'": , .
~3~32~
containing l--20 carbon atoms)] and having an associated anion A~
such as a halide, e.g. chloride or bromide, or trifluoroacetate
anion, with an acid of formula
R4
S
\ / C.COOH (III)
11
\ ~ 3
O.C.COOR
Rb
(wherein Ra and Rb are as hereinbefore defined; R3 represents a
carboxyl blocking group, e.g. as described for R2; and R4 is an
amino or protected amino group~ or with an acylating agent
corresponding khereto, (B) reacting a compound o~ Eormula
R4
~ H H
S N
/ C.CO.NH ~ I ,~ B ~
O.C CoOR5a ~ N ~ 5 CH2X (IV)
R COOR
(wherein Ra, Rb, R4, B and the dotted line are as hereinbefore
defined; R5 and R5a may independently represent hydrogen or a
carboxyl blocklng group; and X is a replaceable residue of a
nucleophile (leaving group), e.g. an acetoxy or dichloroacetoxy
group or a halogen atom such as chlorine, bromine
~ 12~
2 ~
- 13 -
or iodine) or a salt thereof, with a compound of the formula
~N\
N N - R
~=~J (V).
: 5 (wherein R is as defined above);
or (C) alkylating a compound of the ormu1a
R4
I . . .
H H
S C.CO.NU -- I ~ B N
\ 1 5a ~ CH2N ~ N
O.C.COOR COOR
.,: I
Rb (VI)
(wherein Ra, R~, ~4, B and the dotted line are as herein-
before defined; and R5 and R5a both represent carbox~l
blocking groups) with an alkylating agent serving to
introduce the Rl su~stituent into the above triazole ring
in formula (VI);
whereafter, if necessary and/or desired in each instance,
any of the following reactions, in any appropriate sequence,
are carried out:-
i) conversion of a ~-isomer into the desired ~3-
isomer,
ii) reduction of a compound wherein B is ~S-~ O to
~.
. .
3~ Z ~ ~
- 14 -
form a compound whérein B ls ~S9
iii) conversion of a carboxyl group into a non-~oxic
salt or non-toxic metabolically labile ester
function, and
iv) removal of any carboxyl blocking and/or N~
protecting groups.
In the above-described process ~A), the starting
material of formula (II) i~ pref~rably a compound wherein
the dotted line represents a ceph~3-em compound.
Acylating agents whLch may be employed in the
preparation of compounds of formula (I) include acid
halides, particularly acld chlorides or bromides. Such
acylating agents may be prepared by reacting an acid (III)
or a salt thereof with a halogenating a8ent e.g. phos-
phorus pentachLoride, thionyl chloride or oxalyl chloride.
Acylations employing acid halides may be effected
in aqueous and non-aqueous reaction media, conveniently
at temperatures of from -50 to ~50C, preerably -20 to
+30C, if desired in the presence of an acid binding
agent. Suitable reaction media include aqueous keto~es
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), inorganîc bases (e~g.
calcium carbonate or sodium bicarbonate)~ and oxiranes
such as lower 1~2-alkylene oxides ~e.g. ethylene oxide or
. ~
- . ~
~3~2~3
- 15 -
propylene oxide) which bind hydrogen halide liberated in
the acyla~ion reaction.
Acids of formula (III) may themselves be used as
acylating agents in the preparation of compounds of
formula (I). Acylations employing acids (III) are desir-
ably conducted in the presence of a condensing agent, for
example a carbodiimide such as N,N~dicyclohexylcarbodi-
imide or N-ethyl-N'-y-dimethylaminopropylcarbodiimide; a
carbonyl compound such as carbonyldiimidazole; or an
isoxazolium salt such as N-ethyl-5-phenylisoxazolium
perchlorate.
Acylation may also be effected with other amide~
forming derivatives of acids of formula (III) such as, for
example, an activated ester, a symmetrical anhydride or a
mixed anhydrîde (e.g. formed with pivalic acid or with a
haloformate, such as a lower alkylhalo~ormate). Mixed
anhydrides may also be formed with phosphorus acids (for
example phosphoric or phosphorous acids), sulphuric acid
or aliphatic or aromatic sulphonic acids (for example
toluene-~-sulphonic acid). An activated ester may con-
veniently be formed in situ using, for example, l-hydroxy-
- benzotriazole in the presence of a condensing agent as set
out above. Alternatively, the activated ester may be
preformed.
Acylation reactions involving the free acids or
their above-mentioned amide-forming derivatives are
desirably effected in an anhydrous reaction medium, e.g.`
methylene chloride, tetrahydrofuran, dimethylformamide or
acetonitrile.
3~ 3~
- 16 -
.
If desired, the above acylation reactions may be
carried out in the presence of a catalyst such as 4-di-
methylaminopyridine
The acids of formula (III) ~nd acylating agents
corresponding thereto may9 if desired, be prepared and
employed in the form of their acid addition salts. Thus,
for example, acid chlorides may conveniently be employed
as their hydrochloride salts, and acid bromides as their
hydrobromide salts.
The compound of formula ~V) may act as a
nucleophile to displace a wide variety of su~stituents X
from the cephalosporin of formula (IV). To some extent
the facility of the displacement is related to the PKa
of the acid HX from which the substituent is derived~
Thus atoms or groups X derived from strong acids tend9 in
geheral, to be more easlly displaced than atoms or groups
derived from weaker acids. The facllity of the dis-
placement is also related, to some extent, to the precise
identity of the alkyl group in the compound of formula
(V~.
The displacement of X by the compound of formula (V)
may conveniently be effected by maintaining the reactants
in solution or suspension. The reaction is advantageously
effected using from 1 to 20, preferably 1 to 4, moles of
the compound ~V).
Nucleophilic displacement reactions may con~en-
- iently be carried out on those compounds of formula (lV)
wherein the substituent X is a halogen atom or an acyloxy
group for example as discussed below.
. . ~ . -
- 17 - ~ ~3~%~
Compounds of formula tIV) wherein X is an acetoxy
group are convenient starting materials for use in the
nucleophilic displacement reaction with the compound of
formula (V~. Alternative starting materials in this
class include compounds of formula (IV) in which X is the
residue of a substituted acetic acid e.gO chloroacetic
acid, dichloroacetic acid and trifluoroacetic acid.
Displacement reactions on compounds (IV) possessing
X substituents of this class, particularly ln the case
where X is an acetoxy group, may be facilitated by t~e
presence in the reaction medium of iodide or thiocyanate
ions.
The substituent X may also be derived from formic
acid, a haloormic acid such as chloroformic acid, or a
carbamic acid.
When using a compound of formula (IV) in which X
represents an.acetoxy or substituted acetoxy group, it is generally desirable that the group R5 in formula (IV)
should be a hydrogen atom and that B should represent >S.
In this case, the reaction is advantageously effected in
an aqueous medium, preferably at a pH of 5 to 8, particu-
larly 5.5 to 7.
The above-described process employing compounds of
formula (IV) in which X is the residue of a swbstituted
acetic acid may be carried out as described in British
Patent Specification No. 1,241,657.
Z~
When using compounds of formula (IV) in which X is
an acetoxy group, the reaction is conveniently effected
at a temperature of 30~ to llO~C, preferably 50- to 80C.
Halo~ens
Compounds of formula (IV) in which X is a chlorine3
bromine or iodine atom can al50 be conveniently used as
starting materials in the nucleophilic displacement reac-
tion with the comp~nd offormula (V). When using compounds
of formula (IV) in this class, B may represent~ S-~3 0 and
R may represent a carboxyl blocking groupO The reaction
is conveniently effected in a non-aqueous medium which
preferably comprises one or more organic solvents,
advantageously of a polar nature, such as ethers, e.g.
dioxan or tetrahydrofuran, esters, e.g. ethyl acetate,
amides, e~g. formamide and N,N-dimethylformamide, and
ketones, e.g. acetone. Other suitable organic solvents are
described in more detail in British Patent Speciflcation
No. 1,326,531. The reaction medium should be neither
extremely acidic nor extremely basic. In the case of
reactions carried out on compounds of ~ormula (IV) in
which R5 and R5a are carboxyl blocking groups the 3- (3-
alkyl-1,2,3-triazolium)-methyl product will be formed as the
corresp~nding halide salt which may, if desired, be subjected
to one or more ion exchange reactions to ob~ain a salt
having the desired anion~
When using compounds of formula (IV) in which X is
a halogen atom as described above, the reactlon is
conveniently effected at a temperature of -10 to +50C,
.~ .
~ .
'
~3~2~3~ 19
preferably ~10 to ~30C~
In pro~ess (C) above, the triaæolylmethyl
compound of formula (VI) i5 advantageously reacted with a
Cl 4 alkylating agent of the formula RlY wherein ~ is as
defined above and Y is a leaving group such as a halogen
atom (e.g. iodine, chlorine or bromine) or a hydrocarbyl~
sulphonate (e~g. mesylate or tosylate) group, or ~ Y
represents dimethyl sulphate. The alkylation reaction is
preferably carried out at a temperature in the range of 0
to 60C, advantageously 20 to 30C. The reaction may be
conveniently effected in an inert solvent such as an ether
e.g. tetrahydrofuran, an amide, e.g. dimethylformamide, or
a halogenated hydrocarbon, e.g. dichloromethane. Alter-
natively, where the alkylating agent is liquid under the
reaction conditions, this agent can itself serve as a
solvent.
The compound of formula (VI) used as starting
material in process (C) may be prepared for example by
reaction of a compound of formula (IV) (as defined above)
with a triazole of formula
N NH (VII)
in an analogous manner to the nucleophilic displacement
reaction described with respect to process (B)~ This
reaction is preferably carried out in the presence of an
acid scavenging agent. The triazole itself may act as an
acid scavenging agent.
rhe reaction product may be separated from the
~L~ 3~ 2 ~ 20 -
reaction mixture, which may contain9 for example9 un-
changed cephalosporin starting material and other sub-
stances, by a variety of processes including recrystallisa-
tion, ionophoresis, column chromatography and use of ion-
exchangers (for example by chromatography on ion-exchange
resins) or macroreticular resins.
L~-Cephalosporin ester derivatives obtained in
accordance with the process of the invention may be con-
verted into the corresponding L~3-derivative by, for
example, treatment of the L~ -ester with a ba~e such as
pyridine or triethylamine.
A ceph~2-em reaction product may also be oxidised
to yield the corresponding ceph-3-em l~oxide, ~or example
by reaction with a peracid, e.g. peracetic or m-chloro-
perbenzoic acid; the resulting sulphoxide may, ifdesired, subsequently be reduced as described hereinafter
to yield the corresponding ceph-3-em sulphide~
Where a compound is obtained in which B is ~S -~ O
th;s may be converted to the corresponding sulphide by,
for example, reduction of the corresponding acyloxy-
sulphonium or alkoxysulphonium 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, acetone, tetrahydrofuran, dioxan, di-
- methylformamide or dimethylacetamide. The reaction may
i~ be effected at a temperature of from -20- to +50C.
Metabolically lab;le ester derivatives of the
1 ~ 3~ 2 ~ Q 21 ~
compounds of formula (I~ may be prepared by reacting a
compound of formula (I) or a salt or protected derivative
thereof with an appropriate ~sterifying agent such as an
acyloxyalkyl halide (e.g. iodide) conveniently in an inert
organic solvent such as dimethylformamide or acetone,
followed, where ne~essary, by removal of any protecting
groups.
Base salts of the compounds of formula (I) may be
formed by reacting an acid of formula (I) with the
appropriate base. Thus, for example, sodium or potassium
salts may be prepared using the respective 2-ethyl-
hexanoate or hydrogen carbonate salt. Acid addition
salts may be prepared by reacting a compound of Eormula
(I) or a metabolically labile ester derivative thereof
with the appropriate acid.
Where a compound of formula (I) is obtained as a
mixture of isomers, the ~y~ isomer may be obtained by,
for example, conventional methods such as crystallisation
or chromatography.
For use as starting materials for the preparation
of compounds of general formula (I) according to the
invention, compounds of general formula (III) and acid
halides and anhydrides corresponding thereto in their
svn isomeric form or in the orm of mixtures of the ~y~
isomers and the corresponding anti isomers containing at
least 90% of the syn isomer are preferably used.
Acids of formula (III) (provided that Ra and Rb
together with the carbon atom to which they are attached
do not form a cyclopropylidene group) may be prepared by
,~ .
~L3~2
- 22
etherification of a compou~d of ormu1a
R4
S N
~ .COOR6 (VIII)
N
OH
(wherein R4 is as hereinbefore defined and R6 represents
a carboxyl blocking group), by reaction with a compound o
general formula
Ra
T.C.COOR (IX)
Ib
(wherein Ra, Rb and R3 are as hereinbefore defined and
T is halogen such as chloro, bromo or iodo; sulphate; or
sulphonate such as tosylate), followed by removal of the
carboxyl blocking group R6. Separation of isomers may be
effected either before or after such etherification. The
etherification reaction is generally carried out in the
presence of a base, e.g. potassium carbonate or sodium
hydride, and is preferably conducted in an organic solvent,
Eor example dimethylsulphoxide, a cyclic ether such as
tetrahydrofuran or dioxan, or an N,N-disubstituted amide
such as dirnethylormamide. Under these conditions the
configuration of the oxyimino group is substantially
unchanged by the etherification reaction. The reaction
should be effected in the presence of a base if an acid
addition salt of a compound of formula (VIII) is used.
. . .
3~;2843 -
The base should be used in sufflclerlt qu~ntity to neutral~
ise rapidly the ~cid in question.
Aclds of general formula (III) may also be prepared
by reaction of a compound of ormula
R4
,b
S N
-- CO. COOE~6 (X)
(wherein R4 and R are as hereinbefore defined) with a
compound of formula
~a
H2N.o.C.CooR3 (XI)
Rb
(wherein R~, Rb and R3 are as defined above), Eollowed by
removal o the carboxyl blocking group R , and where
necessary by the separation of sy_ and anti isomers.
The last-mentioned reaction is particularly applic-
able to the preparation of acids of form~tla (III) wherein
; Ra and Rb together with the carbon atom to which they are
attached form a cyclopropylidene group. In this case,
the relevant compounds of formula (XI) may be prepared in
conventional manner, e.g. by means of the synthesis
described in Belgian PatentSpecification No. 866,422 for
the preparation of t-butyl l-amino-oxyc~clopropane
carboxylate.
The acids of form~tla (III) may be converted to the
corresponding acid halides and anhydrides and acid addi-
tion salts by conventional methods, for example as
described hereinaboveO
- 2 4~
Where X is a halogen ~iOe~ chlorlne9 bromine or
iodine) atom in formula ~IV), ceph-3~em starting compounds
may be prepared in ~onventional mann~er, e.g. by halogena-
tion of a 7~-protected amino-3-methylceph-3-em-4-carboxy~
acid ester l~-oxide, removal of the 7~-protecting group,
acylation of the resulting 7~am1no compound to form the
desired 7~-acylamido group, e.gO in an analogous manner to
process (A) above, followed ~y reduction of the l~oxide
group later in the sequence~ This is described in
10 British Patent No. 1,326,531. The corresponding ceph-2-
em compounds may be prepared by the method of Dutch
- published Patent Application No. 6,902,013 by reaction of
a 3-methylceph-2-em compound with N-bromosuccinimide to
yield the corresponding 3-bromomethylceph-2-em compound.
Where X ln formula (IV) is an aceto~y group, such
starting materials may be prepared for example by acyla-
tion o~ 7-aminocephalosporanic acid, e.g. in an analogous
manner to process (A) above. Compounds of ~ormula (IV)
in which X represents other acyloxy groups can be
prepared by acylation of the corresponding 3~hydroxy-
methyl compounds which may be prepared for example by
hydrolysis of the appropriate 3-acetoxymethyl compounds,
e.g. as described in British Patent Specifications Nos.
1,474,519 and 1,531,212.
The starting materials of formula (II) are new
compounds. These compounds m~y be prepared in convent-
ional manner9 for example, by nucleophilic displacement
of the corresponding 3-acetoxymethyl compound with the
appropriate nucleophile.
A further method for the preparation of the
~3~ Q
- 25
starting materials of formula ~II) comprises deprotecting
a corresponding protected 7~-amino compound in conven
tional manner e.g. using PC15~
It should be appreciat~d that in some of the above
transformations it may be necessary to protect any
sensitive groups in the molecule of the compound in
question to avoid undesirable side reactions~ For
example, during any of the reaction sequences referred to
above it may be necessary to protect the NH2 group of the
aminothiazolyl moiety, for example by tritylation,
acylation (e.g. chloroacetylation), protonation or other
conventional method. The protecting group may there-
after be removed in any convenient way which does not
cause breakdown of the desired compound, e.g. in the case
of a trityl group by using an optionally halogenated
carboxylic acid, e.g. acetic acid, ormic acid, chloro-
acetic acid or tri1uoroacetic acid or using a mineral
acid, e.g. hydrochloric acid or mixtures of such acids~
preferably in the presence of a protic solvent such as
water or, in the case of a chloroacetyl group, by treat-
- ment with thiourea.
Carboxyl blocking groups used in the preparation of
compounds of formula (I) or in the preparatlon of
necessary starting materials are desirably groups which
may readily be split off at a suitable stage in the
reaction sequence, conveniently at the last stage. It
may, however, be convenient in some instances to employ
non-toxic metabolically labile carboxyl blocking groups
such as acyloxy-methyl or -ethyl groups (e.g. acetoxy-
.
~L3~Z~O
- 26 -
methyl or -ethyl or pivaloyloxymethyl) and retain these in
the final product to give an approprlate ester derivative
o~ a compound of formula (I)~
Suitable carboxyl blocking groups are well kno~n
in the art 3 a list of representative blocked carboxyl
groups being included in British Patent No. 1,399,086.
Preferred blocked carboxyl groups include aryl lower
alkoxycarbonyl groups such as p~methoxybenzyloxycarbonyl,
~-nitrobenzylo~ycarbonyl and diphenylmethoxycarbonyl;
lower alkoxycarbonyl groups such as t-butoxycarbonyl; and
lower haloalkoxycarbonyl groups such as 2,2,2-trichloro-
ethoxycarbonyl. Carboxyl blocking group(s) may
subsequently be removed by any of the appropriate methods
disclosed in the literature~ thus, ~or example, acid or
base catalysed hydrolysis is applicable in many cases, as
are enzymically-catalysecl hydrolyses.
The follow~ng Examples illustrate the invention.
All temperatures are in C. 'Petrol' means petroleum
ether (b.p. 40-60).
T.l.c is thin-layer chromatography using pre-coated plates
(Merck F254,0.25 mm thick coating) which were examined
under ultra-violet light at 254 nm and were developed with
iodine .
Proton magnetic resonance (p.mOr.) spectra are
inserted where appropriate and were determined at 100 MHz.
The integrals are in agreement with the assignments,
coupling constants, J, are in Hz, the signs not being
determined; s = singlet 9 d = doublet, dd = dou~le doublet,
m = multiplet and ABq = AB quartet.0 Preparation 1
imino?acet _e
To a stirred and ice-cooled solution of ethyl
3~
- 27 -
acetoacetate (292 g) in glacial acetic acid ~296 ml) was
added a solution of sodium nitrite (180 g) in water (400
ml) at such a rate that the reaction temperature was
malntained below 10C. Stirring ancl cooling were
continued for about 30 min., when a solution of potassium
chloride (160 g) in water (800 ml) was added. The resu~-
ing mixture was stirred for one hour. The lower oily
phase was separated and the aqueous phase was extracted
with diethyl ether. The extract was combined with the
oil, washed successively with water and saturated brine,
dried, and evaporated. The residual oil, which solidif~d
on standing, was washed with petrol and dried in vacuo
over potassium hydroxide, giving ethyl (Z)-2-(hydroxy-
imlno)-3-oxobutyrate (309 g).
A stirred and ice-cooled solution of ethyl (Z)-2-
(hydroxyimino)-3-oxobutyrate (150 g) in dlchloromethane
(400 ml) was treated dropwise wlth sulphuryl chloride
(140 g). The resulting solution was kept at room temp-
erature for 3 days~ then evaporated. The residue was
dissolved in diethyl ether, washed with water until the
washings were almost neutral, dried, and evaporated. The
residual oil (177 g~ was dissolved in ethanol (500 ml)
and dimethylaniline (77 ml~ and thiourea (42 g) was added
with stirring. After two hours, the mixture was
Eiltered and the residue washed with ethanol and dried to
give the title compound (73 g); m.p. 188 (decornp.).
Preparation 2
Ethyl (Z)-2-hydroxyi no-2-(2-tritylaminothiazol-4-yl)
acetate, hydrochloride
Trityl chloride (16.75 g) was added portionwise
over 2 hours to a stirred and cooled (-30) solution of
,
3~
- 28 -
the product of Prep~ra~ion 1 (12.91 ~) and triethylamine
(8.4 ml) in dimethylformamide (28 ml). The mixture was
allowed to warm to 15~ over one hour9 stirred for a
further 2 hours and then partltioned between water (500
5 ml) and ethyl acetate (500 ml)O The organic phase was
separated, washed with water (2 x 500 ml) and then
shaken with lN HCl (500 ml). The prec~pitate was
collected, washed successively with water (100 ml), ethyl`
acetate (200 ml) and ether ~200 ml~ and dried in vacuo to
provide the title com~_nd a3 a white solid ~16.4 g);
m.p. 184 to 186a (decomp.)O
Preparation 3
~ -(2-
.` tritylaminothiazol-4-yl~ace-tat-e
Potassium carbonate (34~6 g) and t-butyl 2-bromo-
2-methylpropionate (24.5 g) were added to a stirred solu-
tion under nitrogen of the product of Preparation 2
(49.4 g) in dimethylsulphoxide (200 ml) and the mixture
was stirred at room temperature for 6 hours. The mixture
- 20 was poured into water (2 1)7 stirred for lO mins.~ and
filtered. The solid was washed with water and dissolved
in ethyl acetate (600 ml)~ The solution was washed
successively with water, 2N hydrochloric acid, water, and
saturated brine, dried9 and evaporated. The residue was
recrystallised from petrol to give the title compound (34
g~ m.p. 123c5 to 125-.
3~
29
Preparati~n 4
(Z)-2-(2-t-Butoxycarbonylprop-2-oxyimino)~2-~2-trityl-
The product of Preparation 3 ~2 g) was dissolved in
methanol (20 ml~ and 2N sodium hydroxide (3.3 ml) was
added. The mixture was refluxed for 1.5 hours and then
concentrated. The residue was taken up in a mixture of
water (50 ml), 2N hydrochloric acid (7 ml), and ethyl
acetate (50 ml). The organic phase was separated, and
the aqueous phase extracted with ethyl acetate. The
organic solutions were combined, washed successively with
water and saturated brine, dried and evaporated. The
residue was recrystallised from a mixture of carbon
tetrachloride and petrol to give the tLtle campound (1 g),
m~p. 152 to 156 (decomp.).
Preparation 5
Ethyl (Z)-2-(2-trit~laminothiazol-4-yl)-2-(1-t-butoxy-
carbonylcyclobu ~
The product of Preparation 2 (55.8 g) was stirred
under nitrogen in dirnethylsulphoxide (400 ml) with
potassium carbonate (finely ground, 31~2 g) at room
temperature. After 30 minutes, t-butyl l-bromocyclo-
butanecarboxylate (29.2 g) was added. After 8 hours
further potassium carbonate (31.2 g) was added. More
potassium carbonate (6 x 16 g portions) was added during
the next three days and further t-butyl l-brornocyclo-
butanecarboxylate (3045 g3 was added after 3 days. After
4 days in all, the mixture was poured into ice-water (caO
3 litres) and the solid was collected by filtration and
3~3~
_ 30 _
washed well with water and petrol. The solid was
dissolved in ethyl acetate and the solution washed with'
brine (twice), dried with magnesium sulphate and evapor-
ated to a foam. This foam was dissolved in ethyl acetate-
petrol (1:2) and filtered through s;lica gel (500 g).
Evaporation gave the title compound (60 g) as a yellow
foam, ~ (CHBr3) 3400 (NH~ ar.~ 1730 cm (ester).
Preparation 6
(Z)-2-(1-t-But~ _ r _ lobut-l-oxy_mino)-2-(2-trityl-
aminothiazol-4-yl) acetic acid
A mixture of the product of Preparation 5 (3.2 g)
and potassium carbonate (1.65 g) was refluxed in methanol
(180 ml) and water (20 ml) for 9 hours and the mixture
was cooled to room temperature. The mixture was concen-
trated and the residue partitioned between eth~l acetateand water, to which was added 2N HCl (1202 ml). The
organic phase''was separated and the aqueous phase
extracted with ethyl acetate. The combined organic
extracts were washed with saturated brine, dried and
evaporated to give the title compound (2.3 g); AmaX
(ethanol) 265 nm (ElCvm243).
3l
Example 1
a) Diphenylmethyl (lS.6R,7R)-3-Bromomethyl-7-r(Z~-2-
(2-t-butoxycarbonyl-prop-2-oxyimino~-2~2-tritylaminothiaæol-
4-yl)acetamidolceph-3-em-4-carboxylate2 l~Oxide
A solution of the product of Preparatior-~ 4 (0.526g)
in dry tetrahydrofuran ~6 ml) was treated successively
with l-hydroxybenztriazole monohydrate (0.141 g) and
N,N'-dicyclohexylcarbodiimide (0.198 g) in tetra-
hydrofuran (4 ml). The developing suspension was
stirred for 30 minutes at 23 and then filtered. A
solution of diphenylmethyl (lS,6R,7R)-7-amino-3-bromo-
methylceph-3-em-4-carboxylate, l-oxide (0.427 g) in
dichloromethane (260 ml) was treated at 23 with the
; above Eiltrate. The solution was stirred ~or 18 hours
at 20 to 25, evaporated to dryness, then the residue
was dissolvèd :Ln dichloromethane and washed successi.vely
with saturated aqueous sodium bicarbonate, water and
brine, then dried and evaporated in vacuo to a foam
(l.Ol g).
This foam was purified by chromatography on
preparative silica plates using toluene:ethyl acetate:
acetic acid = 190:50:2.5 as eluant. The purified
product was isolated as a foam which was dissolved in
ethyl acetate (5 ml) and precipitated from petrol
(200 ml~ to give the title compo~md (0.69 g) as a
; maxl/EtOH) 268 nm (El/ 182) with a
inflection at 242 nm (ElCm 230), vmax (Nujol) 3375 (NH),
1805 (~-lactam~, 1730(CO2R) and 1688 and 1515 cm (CONH).
~;''
: '
. .
' ~
3~
32
b~ L~ L~
cetami ~ 4-
carboxylate, l-oxide romide salt
A mixture of diphenylmethyl ~lS, 6R~ 7~-3-bromome~hyl-
7-[(Z)-2-(2-t~butoxycarbonylprop-2 oxyimino)-2-(2-
tri~ylaminothiazol--4-yl)acetamido~ceph-3-em-4-carboxylate,
l-oxide (1~05 g) and 1-methyl-1,2,3-triazole (l.l9 g) in
tetrahydrofuran (15 ml) was stirred at 22 to 30 Eor 4.7
days in the absence of light. The mixt~re was evaporated
and the residue triturated with ether and ethyl acetate to
~ give the title com~ound (1 g) as a solid; ~inflec~ion
l~ (CHC13) 267 nm (ElCm 155 E 17,300) and ~m x (Nujo ~ 3600 to
2500 (NH and water), 1798 (~-lactam, 1725 ~C02R) and 1678
15 and 1515 cm 1 (CONH).
c) DiphenylmethYl (6R,7R)-3-(3-methyl-1,2,3-triazolium-
l-yl)methyl-7- ~Z)-2-(2-t-butoxycarbonylprop-2-oxyimino)-2-
(2-tritylaminothiazol-4-yl)acetamid~lceph 3-em-4-carboxylateL
Bromide and Iodide salts
The product of stage b) (0.8 g) in acetone ~5 ml) at
-10 was treated with potassium iodide (0~427 g) and
stirred for 10 minutes.
A further portion of potassium iodide (0.427 g) and
æetyl chloride (0.11 ml) was added and the mixture was
stirred vigorously at ~10 to 0 over 30 minutes. The
mixture was added dropwise to a solution of sodium metabi-
sulphite (0.35 g) in water (20 ml) to give a gummy solid.
The mixture was extracted with dichloromethane and brine and
the organic phase wa~ washed with brine then dried and
Pvaporated to a foam (t.l.c. indicated some unchanged
starting material).
I ra~le nlal k
.
33 -
The above reduction sequence using potassium iodide
and acetyl chloride was repeated exactly as described above
to give the title compound (0.6 g)g mainly as the iodide
salt, t.l~c., Rf 007 (chloroform:met'hanol:acetic acid =
90:16:20), ~ (DMS0-d ) 1.08 and 1.15 t2s, triaæole 4 and
5-H), 3.22 (s, thiazol-5-yl proton), 4.03 (dd, J 9 and 5H
7-H)9 5.70 (s, NMe), and 8.60 ~broad s, CMe2 and t butyl).
d) (6R,7R)-7-r(Z~-2-(Aminothiazo
10 methylceph-3-Pm-4-carboxyla~e
The product of stage c) (1.72 g) was suspended in a
mixture of anisole (1.7 ml) and tri1uoroacetic acid (7 ml)
at 22 for 1 minute. The mixture was evaporated in vacuo
to an oil which was then azeotroped with toluene. The
toluene was removed in ,vacuo and the resulting oil triturated
with ether to give a solid (lo 3 g)~
A suspension oE the above s~lid in anisole (1.3 ml)
and trifluoroacetic acid (15 ml) was stirred for 15 minutes.
The supernatant liquid was decanted off and the solid was
washed with trifluoroacetic acid (10 ml). The combined
trifluoroacetic acid solutions were concentrated in vacuo to
an oil which,on trituration with ether gave a solid (0.9 g).
~, A portion (0.85 g) of this solid was stirred for 10
minutes with a mixture of trifluoroacetic acid (4 ml) and
water (150 ml) and the mixture was successively extracted
with ethyl acetate and et'her. The aqueous layer was freeze~
dried to give the title compound (0.75 g) as a solid
associated with 1.3 moles of trifluoroacetic ac d [a~D -17,9
(c 0.56, DMS0), Ai (pH 6 phosphate~ 235 nm (ElCm24) with
further inflections at 255 nm (El/a207) and 300 nm ~E182)~
~ 34
~ ` . ,
a)
(l-t-butoxycarbonylcvclobut-l-oxyimlno
~ r ~Yi~ 8_1g~
A stirred solution of the product of Preparation 6
(1.167 g) in tetrahydrofuran (15 ml) was treated
successively with l-hydroxybenztriazole hydrate (0.337 g)
and N,N'-dicyclohexylcarbodlimide ~0.495 g) for 30
minutes at 22.
Filtration afforded a solution of the activated
es~er which was added to a solution of dlphenylmet~hyl
(lS,6R,7R)-7-amino-3-bromomethylceph-3-em-4-carboxylate
l-oxide (0.95 g~ in dichloromethane (550 ml). The
solution was stirred for 16 hours then evaporated to
dryness. A solution of the residue in dich.loromethane
was wa~hed successlvely with aqueous sodium bicarbonate9
and brine, and then dried and evaporated to a foam (2.2 g)
which was purified by preparative thin-layer chromato-
graphy (using toluene:ethyl acetate:acetic acid - 40:10:1
for development) to give the title ~ (1.4 g) with
(EtOH) 266 nm (El% 192) and an inflection at
max ,~, lcm
( lcm 224), ~max (Nujol) 3360 (N~) 1805
(~-lactam), 1730 (CO2R) and 1689 and 1520 cm (CONH).
b) Diphenylmethyl (lS,6R17R)-3-(3-methyl-1,2~3-triazolium
-l-yl) met~y~-7-r(Z)-2~ t_b~y~g3~g~l~ssy~L __ut-l-
ox~imino1-2-(2-telcvlaminothiazol~4-yl)acetamido~ce~h-3-em-
4-carboxylate, l-oxide? Bromide Salt
A mixture of diphenylmethyl (lS,6R,7R)-3-bromomethyl-
~L~3~121
- 35
7-[(Z)-2-(1-t-butoxycarbonylcyclobut-l~oxyimino)~2-(2-
trityl3minothia~ol-4~yl)~ceta~ido~ceph~3~em-4~
carboxylate~ l-oxide (1.04 g) and 1-methyl-1,2,3 triazole
(1.240 g) in tetrahydrofuran (8 ml) was stirred at ca 21
for 50 hours.
The solution was evaporated to an oil which~ on
leaching several times with ether gave the title ~
(0.910 g) as an amorphoU~ solid [a]D5-2 (_ ~.9, DMS0),
Ainfl(EtoH) 243 nm (ElCm207, ~23,270) with ~urther
inflections at 265 nm (ElCml70, el9,110), and 310 nm
(ElCm50~ e5,620) and AmaX390 nm (ElCm31, ~3,4853.
c~ ~1:~:~ ''
l-yl) methyl-7-~(Z?-2-(l-t-butoxycarbony~cyclobut-l-oxyimin
-2~(2~tritylarnlno~hlazol-4~ 2~eetami~o~ceph~3~em-
4-carboxylate, Iodide _alt
Potassiurn iodide (0.481 g) w~s added to a cooled
(-10~ mixture of the product of stage b~ (0.816 g) and the
mixture was stirred for 10 minutes at -10. A further
portion of potassium iodide (0.481 g) was added, followed by
acetyl chloride (0.12 ml) and the resulting suspension
stirred for 30 minutes at -10 to 0. The mixtuxe was
poured into a stirred solution of sodium metabisulphite
(0.36 g) in water (20 ml~ and the gummy solid extracted with
dichloromethane. The organic layer was washed with brine,
dried and evaporated to a foam (t.l.c. indicated some
starting material~.
The above produc~ was sub~ec~ed to a similar
reduction sequence ~using potassium iodide and acetyl
chloride as described above~ to give the title ~
' '
6336
~0.713 g) as a foam, t.l.c. RfO.45 (chloroform:methanol:
acetic acid - 90:16:20), and ~(D~SO-d ) 1.06 and 1.12 (2s,
triazole 4 and 5-H), 3.22 (s, thiazol-5-yl proton), 4.05
(dd, J 9 and 5Hz, 7-H), 5.70 (s, NMe)~ 7.2 to 7.8 (m,cyclo-
but-2-yl protons) and 708 to 8.4 (m, cyclobut-3-yl protons~.
d)
The product of stage c) ~0.65 g) in anisole (0.6 ml)
and trifluoroacetic acid (2.4 ml) was stirred at 20 for 1
minute and concentrated in vacuo to give an oil.
Trituration of this oil with ether gave a powder
which was treated with anisole (0.6 ml) and trifluoroacetic
acid (12 ml). After stirring for 15 minutes the solutlon
was decanted to leave a black amorphous paste which was
leached with trifluoroacetic acid.
The combined trifluoroacetic acid solutions were
concentrated in vacuo to an oil which, on treatment with
ether gave a colourless solid (0.35 g)O A portion (0.32 g)
of this solid was treated with a mixture of anisole (0.6 ml),
trifluoroacetic acid (10 ml) and water(10 drops) at 22 for
15 minutes.
The mixture was concentrated to ca 3 ml then poured
into benzene (100 ml). Ethyl acetate and tetrahydrofuran
were added to give a solution. This solution was
concentrated in vacuo to an oil which was stirred with ether
~- to give a powder (0.31 g).
A portion (0.1 g) of this powder was stirred with
water (50 ~I) and trifluoro~cetic acid (1 ml~ for 10
,, ~
.
,, ~
:,
~L3~2~ 37_
minutes. The mixture was waahed wlth ethyl acetate and
ether and the aqueous phase was freeæe-dried to give the
title compound ~0.09 g) associated with 1.2 moles of tri-
fluoroacetic acid; [a]p~13.2 (c 0 49, DMSO), AmaX (pH6
phosphate) 248.5 nm (El/m2217 E16,050) with in1ections at
243 nm (El/m221, E16,0003 and 296 mn (ElCmg8, ~6,860).
Example 3
a) Diphenylmethyl (lS_5,6R~-7-formamido-3~(3_
methyl-~,2j3-triazolium-1-~h~= I-h-3-em-4-
carboxylate, l-Oxide, l~romide Salt
A solution of diphenylmethyl (lS,6R,7R)-3--
bromomethyl-7-formamidoceph-3-em-4-carboxylate, 1-
oxide (1 g) in N,N-dimethylformamide (3 ml) was stirred
for 19 hours at 22 with l-methyl-192,3-triazole (1.10 g).
The reactlon mixture was added dropwise to ether to give
the title compound (1.13 g) as a solid; v (Nujol)
3390 (NH), 1795 (,~-lactam), 1726 (C02R) and 1684 cm
(CONH) and ~(~ISO-d6) 1.07 and 1.22 (2s triazol-4H
and 5H respectively), 1.77 (s, HCONH), 3.82 (dd~ J 9
and 5Hz, 7-H), 4.84 (d, J 5Hz, 6-H), 5.73 (s, ~-Me)
and 5.90 and 6.19 (AB~ J 18Hz, 2-H2).
b) Diphenylmethyl (lS,6R,7R)-7~amino~3-(3-methyl-
1~2,3-triazolium-1-yl)metk~lceph~3~em-4 carboxylate,
l-Oxide Hydrochloride and Bromide Salts
A stirred suspension o the product of stage a)
(1.00 g3 in dry methanol was treated with phosphoryl
chloride (0.48 ml) at 0 to 5 for 2 hours. The
resulting solution was added dropwise to ether (100 ml)
to give a gum which was stirred with ethyl acetate
30 (50 ml) for 13~ hours.
'~
'
.. ~
_38 _~ ~ 3~
The resulting powder was washed with ether to
give the title compound (0.700 g3 a~ a ~olid~ ~max
(EtOH~ 278 nm (E~ cm 107~ vmax (Nujol) 3700 to 2290
(~H3~, 1805 (~ lact~m) and 1729 cm (C02R).
c) ~
2-oxyimino2~2-(2~trityl ~inothiazol~ vl)~ce~ ~lc;-
Phosphorus pentachloride (~ ll g) in dry
dichloromethane (lO ml) at 0 was treated with theproduct of Preparation 4 (0.295 g) and the solution
was stirred for 30 minutes at 0. Triethylamine
(0.16 ml) was added and stirring was continued for 10
minutes at 0. The resulting solution was added drop-
wise over 5 minutes to a vigorously stirred suspension
of the product o stage b) (0.303 g) in dichloromethane
(15 ml) at 0. The mixture was stirred at 0 to 15
for 14 hours and the resulting solution was stored
at -20 for 15 hours. The solution was poured into
ethyl acetate (100 ml) and water (100 ml). The organic
phase was separated and washed successively with
water and brine, then dried and evaporated in vacuo
to a foam (0.4 g). This foam was stirred with ether
(30 ml~ for 30 minutes to give a solid which was washed
with ether to give the title co~ound (0.35 g) as a
solid, [a]22 -16 (c 1.0, DMSO) J ~inf (CHC13) 267 nm
( lcm 169).
The title compound may then be converted into
(6Rj7R~-7~[(Z)-2-(2-aminothiazol-4~yl~-2-(2-carboxy-
prop-2-oxyimino)acetamido]~3-(3-methyl-1,2,3~triazolium~
~ ~ 3~3
_ 39 _
l-yl)methylceph-3-em-4-carboxylate as described in
Example l.
Example 4
a) Diphenylmethyl ~lS~6R~7R)-3-(1 7 2~3-triazolium-
1~ methyl-7 [(Z)-2~ t-butoxycar'bonylcyclobut-1-
oxyimino)-2-(2- tritylaminoth-iazol-4~yl)acetamido~ceph-
3-em-4-carboxylate~ l-oxide
A solution of the product of Example 2a) (l g)
in N,N-dimethylformarnide (3 ml) was treated with 1,2,3-
triazole (0.113 g). The reaction mixture was stirredat ca. 20 for 24 hours and then more triazole (0.113 g)
was added and the mixture was stirred for ca. 2 hours
at ca 20 and then refrigerated for ca. 60 hours. The
mixture was diluted with ethyl acetate (150 ml) and
lS the organic solution was washed with 2N-hydrochloric
acid (2 x 50 ml) and brine (50 ml) t'h~n dried over
magnesium sulphate and evaporated in vacuo to a foam
(0.88 g). Chromatography of this foam on preparative
thin-layer plates using toluene:ethyl acetate:acetic acid =
20:40:1 as eluant gave the title compound ~O l g) as
a solid with ~inf (EtOH) 260 nm (ElCm 199) and 300.5 nm
(ElCm 61) and ~ (DMSO-d6), 2.03 and 2.26 (2s, triazolium
protons~, 3.19 (s, thiazol 5-H)~ 3.8 to 4.1 (m, 7-H),
4.92 (d, J 5Hz, 6-H), 7.4 to 7.8 (m, cyclobut-2 and
4-yl protons), 7.8 to 8.2 (m, cyclobut-3-yl protons)
and 8.62 (s, t butyl).
b) Diphenylmethyl (15~6R,7R~-3-(3-methyl-1,2,3-
triazolium-l-yl)methyl-7-~(Z)-2-(1 t-butoxycarbonyl-
cyclobut-l--oxyimino~~2-(2~tritylaminothiazol-4-yl)-
acetamido]c_ph-3-em-4-carboxylate, _oxide, Iodide Salt
A solution of the Product from stage a) (0.08 g)
- 40 ~
in iodomethane ~ 2 ml) was stirred at 22 for 66 hours.
Excess iodomethane was evaporated in vacuo to give a
solid. This product was triturated with ether and the
solid collected by filtration and dried in vacuo over
phosphorus pentoxide to give the title compound (0.067 g)
as a solid; ~a~D -16~2 (c O.5, DMSO), ~i f (EtOH)
260 nm (ElCm 160) and 305 nm (ElCm 58).
Ex m~le 5
a) t~Butyl (6R,7R)-3-Acetoxymethyl-7-~(Z)-2-(2-t-butoxy-
carbonylprop-2-oxyimino)-2-(2-tritYlaminothia~oL-4~yl)
acetamido~ ce~h-3-em-4-carboxylate
A stirred solution of the product of Preparation 4
(572 mg) and t-butyl ~6R,7R)-3-acetoxymethyl-7-aminoceph-
3-em-4~carboxylate (328 mg~ in dimethylfonnamicle (10 ml)
was cooled to 0, and l-hydroxybenzotriazole (150 mg) was
added, followed by dicyclohexylcarbodiimide (225 mg). The
mixture was warmed to room temperature, stirred for 5
hours, and allowed to stand overnight. The mixture was
filtered, and the white solid washed with a little ether.
The filtrate and washings were diluted with water ~50 ml)
and extracted with ethyl acetate. The organic extracts
were combined, washed successively with water, 2N
hydrochloric acid, water, sodium bicarbonate soLution, and
saturated brine, dried and evaporated. The residue was
elu-ted through a silica column with ether. The product-
containing eluate was collected and concentrated to give
the title compound (533 mg). A portion was recrystallised
from di-isopropyl ether, m.p. 103 to 113 (decomp.3;
[a~D + 8.5 (c, 1.0, DMSO).
3~
- 41 -
4-yl?_2-(2-carboxyE~roe~2-oxyimino)-acetami ~ ce~h 3-em-
The product of Stage a) ~200 g) was dissolved in
formic acid (800 ml) pre-cooled to ~10 and
concentrated hydrochloric acid (60 ml) was added over 5
minutes to the stirred mixture. Stirring was continued
at 20 to 22 for 14 hours before cooling to +10 and
filtering. The bed was washed with formic acid (30 ml).
The combined filtrate and wash were concentrated by
evaporation at 20 to a yellow foam which was triturated
with ethyl acetate (800 ml). The solid which deposited
was collected by filtration, washed with ethyl acetate
(200 ml) and dried in vacuo at room temperature
overnight to glve the title compound (124.6 g) AmaX
(ethanol) 234.5 nm (ElCm 311)-
_ (6R,7R~7-[(Z)-2-(2-A inothiazol-4-yl)-2-(2-
carboxyprop-2-oxyimino)acetamido~-3-(3-methy1-1,2,3-
triazolium-l~yl)methyl-ceph-3-em-4-carboxylate~sodium
Salt
(6R77R)-3-Acetoxymethyl-7-[(Z)-2-(2-aminothiazol-
4-yl)-2-(2-carboxyprop-2-oxyimino)acetamido~-
ceph-3-em-4-carboxylic acid, hydroch]oride salt (0.564 g),
sodium hydrogen carbonate (0.27 g !,sodium iodide (1.8 g ),
water (0~30 ml) and 1-methyl-1,2,3-triazole (0.25 ml)
were heated to 80 for 14 hours and the solu-tion was left
to cool. The resulting solid was triturated with acetone
(10 ml) and the product was filtered off, washed with
acetone a~d ether and dried rapidly in-vacuo to give a
' .
' :
,
- \
~ 3~2~
- 42 -
solid (0.66 g). This product was purified on a column
of Amberlite XAD-2 resin (100 g) which was eluted
successively with water then water:ethanol (4:1).
Appropriate fractions were combinPd, evaporated to
ca. 150 ml then freeze-dried to give the title
compound (0.203 g) as a foam with ~ma~(pH6 buffer)
` 238 nm (ElCm295) with in~lections at 256 nm (ElC%m270)
and 295 nm (E lCml4i3 and ~(D20) 1.39 and 1.49 (2
broad s, triazole protons), 3.00 (broad s, thiazol 5-H),
; 10 5.69 (s, ~CH3), 6.29 and 6.62 (ABq, J ca. 18 Hz, 2-H2)
and 8.52 (s, CMe~).
.'; ' ~
.
~ '
-
~3~Z~
- 43
The antibiotic compounds of the invention may be
formulated for administration in any convenient way, by
analogy with other antibiotics and the invention therefore
includes within its scope pharmaceutical compositions
comprising an antibiotic compound in accordance with the
invention adapted to use in human or veterinary medicineO
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
~nit dose form in ampoules, or in multi-dose containers,
if necessary with an added preservative. ~le compositions
may also take such forms as suspensions, solutions, or
i5 emulsions in oily or aqueous vehicles, and may contain
formulatory agents 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.
If desired, such powder formulations may contain
an appropriate non-toxic base in order to improve the
water-solubility of the active ingredient and/or to
ensure that when the powder is reconstituted with water,
.
.
44 -
the pH of the resulting ~queous formulation ls physio-
logically acceptable. Alte~natively, the base may be
present in the water with which the powder is reconstit-
uted. The base may be, for example, an inorganic base
such as sodium carbonate, sodium bicarbonate or sodium
acetate, or an organic base such as lysine or lysine
acetate.
The antibiotic compounds may also be formulated as
suppositories, e.g. containing conventional suppository
bases such as cocoa butter or other glycerides.
For medication of the eyes or ears, the prepara-
tions may be formulated as individual capsules~ an liquid
or semi-solid form, or may be used as drops.
Compositions for veterinary medicine may, for
example, be formulated ~s intramammary preparations in
either long acting or quick-release bases.
The composltions may contain from 0.1% upwards,
e.g. 0.1-99%, of the active material, depending on the
method of administration. When the compositions comprise
dosage units, each unit should preferably contain 50-lS00
mg of the active ingredient. The dosage as employed for
adult human treatment will preferably range rom 500 to
6000 mg per day, depending on the route and frequency of
administration. For example, in adult human treatment
; 25 1000 to 3000 mg per day administered intravenously or
intramuscularly will normally suffice. 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 or
~ other cephalosporins.
:
~ ~ 34~5~ ~ ~
The following formulation illustrates how a
compound according to the invention may be made up
into a pharmaceutical composition
Formulation - For Injection
....
5 Formula ~er vial
(6R,7R)-7-~(Z)-2-(2-Aminothiazol 4-
yl~-2-(1-carboxycyclobut-l-yloxyimino)acetamido]-
3-(3-methyl-1,2,3-triazolium-1 yl)methylceph-
- 3-em-4-carboxylate 500 mg
10 sodium carbonate, anhydrous 47 mg
Method
Blend the sterile cephalosporin antibiotic with
sterile sodium carbonate under aseptic conditions. Fill
aseptically into glass vials under a blanket of sterile
nitrogen. Close the vials using rubber dlscs, or plugs,
heLd in position by alumlnium overseals, thereby
preventing gaseous exchange or ingress of microorganisms.
Reconstitute the product by dissolving in Water for
Injections or other suitable sterile vehicle shortly be
before administration.
(6R,7R)-7-[(Z)-2-(aminothiazol-4-yl)-2-(2-carboxyprop-
2-oxyimino)-acetamido~-3-(3-methyl-1,2,3~triazolium-1-yl)
methyl-ceph-3-em~4-carboxylate may be formulated in a
similar manner.
