IE50648B1 - Intermediates in the preparation of 7-(2-amino-4-thiazolyl)-acetamido-ceph-3-em-4-carboxylic acid derivatives - Google Patents

Description

The present invention relates to compounds which are useful intermediates in the preparation of substituted, alkyloxime derivatives of 7~(2-amino-4-thiazolyl)acetamido-ceph-3-em-4-carboxylic acid, which derivatives are believed to possess good antibiotic activity.

Patent Specification No. 1500/80 (which describes the “parent invention), from which the present application is divided out, provides the following substituted alkyloxime derivatives, being the syn isomers of the general formulai (wherein R represents a radical n represents an integer of from either of the groups -(CHg^-S-Rg, in which 1 to 4 and Rg represents c • '> ' - 2 a radical -(CH2)n-S-CN, in which n represents an integer from 1 to 4; or a radical -CHF2; R^ represents a hydrogen or chlorine atom; a methoxy, acetoxymethyl, oarbamoyloxymethyl or azidomethyl radical; an alkyl, eycloalkyl or alkylthio radical containing up to 5 carbon atoms; a radical -CHg-S-R1, in which R' represents a substituted or unsubstituted heterocyclic radical containing a nitrogen atom in the heterocyclic ring, or an acyl radical having from 2 to 4 carbon atoms; or a radical -NH-g-Alk in which Alk represents an 0 alkyl radical containing up to 4 carbon atoms; and A represents a hydrogen atom or an easily cleavable ester-forming group,or - except inthe case where R represents the radical -(CHg^-S-Rg -an alkali metal atom, a substituted or unsubstituted ammonium group, or an equivalent of an alkaline earth metal or magnesium atom) and their addition salts with organic or mineral acids.

The derivatives of the parent invention^ and various precursors thereof defined hereinafter, are syn isomers by virtue of the syn configuration of the oxime group substituted into the acetyl moiety of the relevant compound, and the term syn isomer is used herein to indicate a compound having such configuration.

In the case of a derivative wherein A represents a hydrogen atom and R represents a radical -(CHg^-S-Rg, the group Eg (i.e. -G(»NH)NHg or -G(iNH)NH-NH2) may become protonated by a hydrogen ion released from the carboxy - 3 group substituted into the 4-position of the cephem ring of the derivative, so that the derivative is in effect an internal salt. The parent invention includes all such internal salts, and the formulae appearing herein should be construed accordingly.

It will be appreciated that the syn isomers of general formula I wherein A represents an alkali metal atom, a substituted or unsubstituted ammonium group or an equivalent of an alkaline earth metal or magnesium atom are in fact salts, which may be formed by reaction with appropriate bases, of the corresponding syn isomer wherein A represents a hydrogen atom. For convenience, such syn isomers will be referred to herein as basic salts. The term equivalent of an alkaline earth metal or magnesium atom indicates that the salt only contains that portion of the metal atom corresponding to a single valence.

As well as existing in the form indicated by general formula I above, the derivatives of the parent invention may also exist in the tautomeric form indicated by the formula: H $ - 4 Both forms are equally the subject of the parent invention and the formulae appearing herein should be construed accordingly.

When the substituent represents an alkyl or eyeloalkyl radical, it will typically be a methyl, ethyl, propyl, isopropyl, butyl, isobutyl, tert-butyl. pentyl, sec-pentyl, tert-pentyl. cyclopropyl, cyclobutyl or cyclopentyl radical.

When R^ represents an alkylthio radical, it may typically be a methylthio, ethylthio, propylthio, isopropylthio, butylthio, isobutylthio or tert-butylthio radical.

When R^ represents the radical -CHg-S-R', R' may typically be a 1,2,3- 1,2,5- I»2»2*-- 1.3,4-thiadiazolyl ring, a 1-H tetrazolyl ring, a 1,3-thiazolyl ring, a 1,2,3- 1,2,4- or 1,3,4-triazolyl ring, or a 1,2,3- 1,2,41,2,5- or 1,3,4-oxadiazolyl ring - these rings being unsubstituted or substituted by one or more radicals selected from the group formed by methyl, ethyl, propyl, isopropyl, methoxy, ethoxy, propyloxy, isopropyloxy, amino, hydroxycarbonylmethyl, dimethylaminoethyl and diethylaminoethyl radicals. R' may equally represent an acetyl, propionyl or butyryl radical.

When R^ represents a radical -NH-G(=0)-Alk, it may typically be an acetamido, propionylamido, butyrylamido, isobutyrylamido or valerylamido radical.

When the substitutent A represents an easily 0648 - 5 cleavable ester-forming group, the syn isomer of general formula I is an ester of the corresponding syn isomer wherein A represents a hydrogen atom. The easily cleavahle ester-forming group may be any group which is cleavable from the particular molecule to which it is attached without substantially affecting the structure of the remainder of the molecule, apart from sometimes also removing protecting groups where these are present - as is the case in certain precursors of the syn isomers of general formula I described hereinafter. Typical of easily cleavable ester-forming groups which may form the substitutent A in general formula I are alkoxyalkyl radicals such as a methoxy-methyl, ethoxy-methyl, isopropoxy-methyl, a-methoxy ethyl or a-ethoxyethyl radical, alkylthioalkyl radicals such as a methylthiomethyl, ethylthiomethyl or isopropylthiomethyl radical, and acyloxyalkyl radicals such as a pivaloyloxymethyl, acetoxymethyl, propionyloxymethyl, isobutyryloxymethy1, isovaleryloxymethyl. propionyloxyethyl, isovaleryloxyethyl, 1-acetoxyethyl, 1-acetoxypropyl, 1-acetoxybutyl, 1-acetoxyhexyl or 1-acetoxyheptyl radical.

Those of the syn isomers of general formula I that are basic salts will typically be formed with a sodium, potassium or lithium atom, an ammonium group of an equivalent of a calcium or magnesium atom, although the salts may equally be formed with a wide variety of organic bases, such as trimethylamine, diethylamine, triethylamine, methylamine, propylamine, N,N-dimethyl-ethano1amine, t ris-(hydroxymethyl)-aminome thane, - 6 ethanolamine, pyridine, picoline, dicyclohexylamine, Ν',N'-dibenzylethylenediamine, morpholine, benzylamine, procaine, lysine, arginine, histidine or N-methylglucamine.

The syn isomers of general formula I mentioned above may form addition salts with organic or mineral acids» since they all contain at least one salifiable amino radical. The edition salts may for instance be formed with organic acids such as acetic, trifluoroacetic, maleic, tartaric, methanesulphonic, benzenesulphonic or p-toluenesulphonic acid, or with mineral acids such as hydrochloric, hydrobromic, hydriodic, sulphuric or phosphoric acid.

A preferred group of derivatives of the parent invention are those wherein R^ represents a hydrogen atom, a radical -CHg-S-R' wherein R' represents a l-methyl-l(H)-tetrazolyl or 2-methyl-l,3,4-thiadiazolyl ring, an acetoxymethyl radical, or an azidomethyl radical - especially those wherein in addition the substituent R represents either the radical -(CHgS~C(=NH)-NH2 or the radical -CHFg.

The derivatives of the parent invention described in the Examples set out hereinafter are particularly preferred, and this applies especially to 3-acetoxymethyl-7-[2-(2-amino-thiazol-4-yl)-2-(2-amidinothio-ethoxyimino)-ac etamido]-ceph-3-em-4-carboxylic acid, syn isomer, in the form of an internal salt, of its addition salts with a mineral or organic acid, or of its esters formed with an easily cleavable ester-forming group; and to 3-acetoxymethyl-7-[2-(2-amino-thiazol-4-yl)-2-(difluoromethoxyimino)S0®48 - 7 -acetamido]-ceph-3-em-4-carboxylic acid, syn isomer, its basic salts with alkali or alkaline-earth metals, magnesium, ammonium or organic amino bases, its esters with easily cleavable ester-forming groups, and its addition salts with mineral or organic acids.

The parent invention also provides processes for the preparation of the derivatives of its invention.

The syn isomers of general formula I wherein R represents the radical -(CHg^-S-Rg or the radical 10 -(CHg^-S-CN, and A represents a hydrogen atom or an easily cleavable ester-forming group, may be prepared by a process in which a syn isomer of the general formula: (wherein fi'2 represents a hydrogen atom or a protecting 15 group, represents a hydrogen atom or an easily cleavable ester-forming group, Rj is as defined above, n represents an integer of 1 to 4 and Hal represents a halogen atom) is treated with one of the following reagents: a) a compound of the formula r 80648 - 8 NH-NH-R^ in which R^ represents a protecting group, b) a conpound of the fomula K-C-S-R^ in which R^ represents an ammonium group or an alkali metal atom, or c) thiourea to obtain the desired product of the general formula: wherein R^, R'2 and A^ are as defined above and Rc represents a radical -C(»NH)-NH2, a radical -C(«NH)-NH-NH-R4 or a cyano radical.

The treatment of the syn isomer of general formula 10 II with the reagent a), b) or c) is preferably carried out in a polar organic solvent such as hexamethylphosphorotriamide, chloroform, dimethyl formamide, acetone or dioxan.

The treatment may also be carried out in the 15 presence of a base. In the absence of a base, the product v_ - 9 10 of general formula la* will generally be obtained, in the form of its hydrohalide addition salt formed, with the acid H-Hal, where Hal is the halogen represented by the substituent Hal in general formula II. The unsalified syn isomer of general formula la’ may be released by treatment with a base.

The substituent Hal will preferably be a bromine or iodine atom.

The syn isomers of general formula I wherein B represents a radical -CHFg and A represents a hydrogen atom or an easily cleavable ester-forming group may be prepared by a process in which a syn isomer of the general formula: II' (wherein B'g, and are as defined above) is treated, with a compound of the formula Hal^-CHFg, in which Hal^ represents a chlorine or bromine atom, to obtain the desired product of the general formula: r wherein A^, R^ and R'g are as defined above.

The treatment with the compound of formula HaljCHFg of the syn isomer of general formula II' is preferably carried out in the presence of a mineral base such as 5 sodium or potassium hydroxide, or sodium or potassium carbonate or acid carbonate.

An anhydrous organic solvent is advantageously employed, such as anhydrous ethanol, dioxan, methanol, isopropanol or tetrahydrofuran, or a mixture of these.

It will be appreciated that some of the syn isomers of general formula la' and lb' are syn isomers falling within general formula I atove- that is, those wherein R'g represent a hydrogen atom and Rc in general formula la' does not represent a radical -C(»NH)-NH-NH-R^. The 15 remaining syn isomers of general formula Ia' and lb', which are not syn isomers of general formula I, are those containing a protecting group R^ or R’g, and these syn isomers may be converted into syn isomers of general formula I simply by removing the protecting group(s).

Where a syn isomer of general formula Ia' or lb' - 11 contains an easily cleavable ester-forming group as the substituent Ap as well as a protecting group R^ or R'2, it is advisable also to cleave the ester-forming group, so as to form a syn isomer of general formula I wherein A is a hydrogen atom. Also, since it is preferred to prepare the syn isomers of general formula I that are esters by esterifying a corresponding syn isomer of general formula I wherein A represents a hydrogen atom, any ester-forming group A^ present in a syn isomer of general formula Ia’ or lb' is preferably cleaved whether or not the syn isomer also contains a protecting group.

As will be described hereinafter, all of the protecting groups R^ or R'2 and the ester-forming group A^ may be removed from a syn isomer of general formula la* or lb' in a single step or in a plurality of steps, depending on the precise nature of the protecting group or esterforming group.

Accordingly, where a syn isomer of general formula Ia' or lb', formed aa described herein, contains a protect20 ing group R'2 or R^, or an ester-forming group A^,the processes will generally comprise a supplementary step or steps of removing the protecting group or groups and/or the ester-forming group A^ so as to form the corresponding syn isomer of general formula I wherein A represents a hydrogen atom.

The purpose of the protecting groups R'2 or R^ is to protect the amino group to which they are attached from S0648 - 12 chemical attack during the present processes.

Any group serving the purpose may be chosen, provided that it is removable from the amino group without substantially affecting the structure of the remainder of the molecule of which the amino group forms a part, other than perhaps by removing other protecting groups and/or easily cleavable ester-forming groups where these are present.

The protecting groups will normally be chosen from among those that are removable by action of hydrolysis or hydrogenolysis agents or thiourea, and accordingly they will normally be chosen from among alkyl radicals of from 1 to 6 carbon atoms, aliphatic acyl groups, aromatic or heterocyclic acyl groups, substituted or tinsubstituted carbamoyl groups, aralkyl groups (in which the alkyl moiety contains up to 5 carbon atoms) and halo-alkyl groups.

Among aliphatic acyl protecting groups the following are preferred: lower alkanoyl groups such as a formyl, acetyl, propionyl, butyryl, isobutyryl, valeryl, isovaleryl, oxalyl, succinyl or pivaloyl group; and lower alkoxy or cycloalkoxy carbonyl groups such as a methoxycarbonyl, ethoxycarbonyl, propoxycarbonyl, l-cyclopropylethoxycarbonyl, isopropoxycarbonyl, butoxycarbonyl, tert-butoxycarbonyl, pentyloxycarbonyl, tert-pentoxycarbonyl or hexyloxycarbonyl group.

Among aromatic acyl protecting groups the following - 13 are preferred: benzoyl, toluoyl, naphthoyl, phthaloyl and mesyl groups; phenylacetyl and phenylpropionyl groups; and the arylalkoxycarbonyl groups such as a benzyloxycarbonyl group.

The acyl protecting groups may be substituted, for example by a chlorine, bromine, iodine or fluorine atom such as in the case of a chloroacetyl, dichloroacetyl, trichloroacetyl, trifluoroacetyl or bromoacetyl group.

Other preferred dcyl protecting groups are the chlorobenzoyl, paranitrobenzoyl, paratert-butylbenzoyl, phenoxyacetyl, caprylyl, n-decanoyl or acryloyl group.

When a protecting group is an alkyl radical it is preferably a tert-butyl or tert-amyl group; and when a haloalkyl group it is preferably a trichloroethyl group.

The preferred lower aralkyl protecting groups are the benzyl, 4-methoxy-benzyl, phenylethyl, trityl, 3,4-dimethoxy-benzyl and benzhydryl groups.

The preferred substituted carbamoyl protecting groups are the methylcarbamoyl, phenylcarbamoyl and naphthylcarbamoyl groups. The corresponding thiocarbamoyl groups may also be employed.

The protecting groups preferred above all others for uas in the present processes are however chosen from among the trityl, chloroacetyl, tert-pentyloxycarbonyl, tert-butyloxycarbonyl and benzyloxycarbonyl groups.

It should be appreciated that the protecting groups - η specified above are not the only groups which may be employed. Any suitable group may be used, and indeed many not specified above are known in the field of the chemistry of peptides.

The easily cleavable ester-forming group Αχ in the syn isomers of general formulae Xa' and lb' prepared according to this invention may be an alkyl radical such as a butyl, isobutyl, tert-butyl, pentyl or hexyl radical; or an acyloxyalkyl radical such as an acetoxymethyl, propionyloxymethyl, butyryloxymethyl, valeryloxymethyl, pivaloyloxymethyl, 2-acetoxyethyl, 2-propionyloxyethyl or 2-butyryloxyethyl radical. Αχ may also be a 2-mesylethyl, 2-iodoethyl, β,β,β-trichloroethyl, vinyl, allyl, ethynyl, propynyl, benzyl, 4-methoxybenzyl, 4-nitrobenzyl, phenylethyl, trityl, diphenylmethyl or 3,4-dimethoxybenzyl radical; or a phenyl, 4-chlorophenyl, tolyl or tert-butylphenyl radical.

Acidic or basic hydrolysis., or hydrolysis involving hydrazine, may be used to remove various kinds of protecting groups Bg and from the syn isomers of general formulae la' and lb'.

Preferably, acid hydrolysis is used to remove substituted or unsubstituted alkoxycarbonyl or cycloalkoxycarbonyl groups, such as a tert-pentyloxycarbonyl or tertbutyloxycarbonyl group, substituted or unsubstituted arylalkoxycarbonyl groups such as a benzyloxycarbonyl group, and the trityl, tert-butyl or 4-methoxy-benzyl groups. - 15 The acid employed is preferably hydrochloric, benzene sulphonic, paratoluene sulphonic, formic or trifluoroacetic acid, although other mineral or organic acids may be used.

Basic hydrolysis is used preferably to remove acyl groups such as the trifluoroacetyl group.

The base employed is preferably a mineral base such as an alkali metal hydroxide - for example sodium hydroxide or potassium hydroxide - although other bases such as magnesia, baryta, an alkali metal (preferably sodium or potassium) carbonate or acid carbonate, or sodium or potassium acetate may also be used.

Hydrolysis using hydrazine is preferably used to remove protecting groups such as the phthaloyl group.

Certain protecting groups, for example the trichloro ethyl group may also be removed with a zinc/acetic acid system.

Benzhydryl and benzyloxycarbonyl protecting groups may be removed with hydrogen in the presence of a catalyst.

The chloroacetyl group may be removed by the action of thiourea in a neutral or acidic medium, according to the type of reaction described by MASAKI (JACS, 90, 4-508, 1968) Other means, known from the literature, of removing protecting groups may also be used.

The easily cleavable ester-forming group A^, may be cleaved from the syn isomergof general formulae la' and lb* under conditions similar to those described above for the - 16 removal of the protecting groups Pi, or R^. Inter alia, acid or basic hydrolysis may be used.

Preferably, acid hydrolysis is used to remove the radicals such as substituted or unsubstituted alkyl or aralkyl radicals, in which case an acid such as hydrochloric, formic, trifluoroacetic or p-toluene sulphonic acid may be used. Other values of the ester-forming group A^ may be cleaved according to processes which will be known by a man skilled in the art.

Preferably, work should be carried out under moderate conditions, that is to say at ambient temperature or by heating slightly.

It should be appreciated that although in certain circumstances all of the groups R'2, R^ ma7 be removed or cleaved from the same molecule at the same time, it will sometimes be necessary, for example when the groups are of different types, to use a succession of different reagents described above.

During ihe reactions described above, a fraction of the products obtained may be ceph-2-em compounds (Δ2) rather than the desired oeph-3-em compounds (Δ5). In such a case it is desirable to convert the fraction of products Δ2 into products Δ^.

Work may he carried out according to a scheme known in the literature for compounds having a cephem nucleus.

The scheme is as follows: the produot containing a fraction Δ2 is oxidised so as to obtain the corresponding sulphoxide. - 17 Preferably a peracid such as metachloroperbenzoic acid is used. The conversion of the sulphoxide of Δ2 to the sulphoxide of Δ^ will then take place in the presence of a hydroxylated solvent or water. Finally, the reduction of the sulphoxide Δ^ is carried out in the presence of an acid halide or phosphorus trichloride, to give the desired product. This type of conversion from Δ2 to Δ^ products has been described, for example, by: KEISER and Colleagues J. Org. 35, 2430 (1970); SPEY and Colleagues, J.Org, 40, 2411 (1975); u.S. Patent No. 3,705,897; or German Patent No. 1,937,016.

The syn isomers of general formulae la' and Ib' may be prepared by an alternative process in which a syn isomer of the general formula: (wherein R'2 is as defined above and R represents the radical -(CH^^-S-Rc, in which n and Rc are as defined above, or the radical -CHF2),or a functional derivative thereof, is reacted with a compound of the general formula: r (wherein A^ and are as defined above) to obtain the desired syn isomer of formula Ia’ or lb'.

Where a functional derivative of the syn isomer of formula III is employed, this may he a halide, a symmetrical or mixed anhydride, an amide, an azide or an activated ester.

An example of a mixed anhydride is that formed with isobutyl chloroformate or tosyl chloride; and an example of an activated ester is that formed with 2,4-dinitrophenol or that formed with l-hydroxybenzo-[l]-triazole. The halide may be the chloride or the bromide.

Where an anhydride is employed as functional derivative, it may be formed in situ by the action of Ν,Ν-disubstituted carbodiimides, for example N,N-dicyclo15 hexyl carbodiimide.

The azide or amide may equally be employed as the functional derivative.

The reaction between the syn isomer of general formula III, or a functional derivative thereof, and the compound of general formula IV is preferably carried out in an organic solvent such as methylene chloride. However, other solvents such as tetrahydrofuran, chloroform or Ο 6 4 8 - 19 dimethylformamide may also be used.

When an acid halide,or a mixed anhydride formed by the action of isobutyl chloroformate, of the syn isomer of general formula III is employed, the reaction preferably is carried out in the presence of a base. This may be a mineral base such as sodium hydroxide, potassium hydroxide or sodium or potassium, carbonate or acid carbonate, or an organic base such as sodium acetate, triethylamine, pyridine, morpholine or N-methyl morpholine.

The reaction temperature should in general be no greater than ambient temperature.

The syn isomers of general formula III wherein R represents the radical -(CH2)n-S-Rc may themselves be prepared by treating a syn isomer of the general formula: ^C^j^Hal (wherein R'2, n and Hal are as defined above) with one of the reagents a), b) or c) defined above, thereby to obtain the desired product of general formula III.

The treatment of the syn isomer of general formula V with the reagent a), b) or c) is preferably carried out in tbe preferred manner described above in relation to the c - 20 treatment of the syn isomers of general formula II with a reagent a), b) or c).

The substituent Hal in general formula V will preferably be a bromine or iodine atom.

The remaining syn isomers of general formula III wherein R represents the radical -CHFg may be prepared by treating a syn isomer of the general formula: (wherein R'g is as defined above) with a compound of the formula Hal^-CHFg, in which Hal^ is as defined above, to obtain the desired product of general formula III.

The treatment of the syn isomer of general formula V' with the compound of fonnula Hal^CHFg is preferably carried out in the preferred manner described above in relation to the treatment of the syn isomers of general formula II' with the compound of formula HaljCHFg.

The syn isomers of general formula I that are basic salts may be prepared by salifying the corresponding syn isomers wherein A represents a hydrogen atom in a conventional manner.

The salification may for example be carried out by treating the syn isomer of general formula I wherein A represents a hydrogen atom, or a solvate (for example the c 0 6 4 8 - 21 ethanolic solvate) or a hydrate thereof, with an appropriate mineral hase, such as sodiuin or potassium hydroxide, sodium or potassium aoid carbonate, or sodium or potassium carbonate. Alternatively however, the salifica5 tion may be effected with appropriate salts of mineral acids, such as tri-sodium phosphate, or of organic acids.

Where a salt of an organic acid is employed, this may for example he the sodium salt of a straight or branched, saturated or unsaturated aliphatic carboxylic acid containing from 1 to 18, and preferably from 2 to 10, carbon atoms. The aliphatic chain of such an acid may he interrupted by one or more heteroatoms such as an oxygen or sulphur atom, or be substituted by one or more aryl radicals, such as a phenyl, thienyl or furyl radical, hy one or more hydroxyl radicals, by one or more halogen atoms, such as a fluorine, hromine or preferably a chlorine atom, by one or more lower (C^-C^) carboxylic or alkoxycarbonyl radicals, such as a methoxycarbonyl, ethoxycarbonyl or propyloxycarbonyl radical, or by one or more aryloxy radicals, such as a phenoxy radical.

Salts of aromatic acids may also he used if they are sufficiently soluble, as are for instance the salts of benzoic acids substituted preferably by one or more lower (C-j-C,.) alkyl radicals.

Specific examples of salts of such organic acids are salts of formic, acetic, acrylic, butyric, adipic, isobutyric, n-caproic, isocanroic. chloropropionic, crotonic, phenylacetic, 2-thienylacetic, 3~thienylacetic, - 22 4-ethylphenylaeetic, or glutaric acid, salts of the monoethyl ester of adipic acid and salts of hexanoic, heptanoic, decanoic, oleic, stearic, palmitic, 3-hydroxypropionic, 3- methoxypropionic, 3-nethylthiobutyric, 4-chlorobutyric, 4- phenylbutyric, 3-phenoxybutyric, 4-ethylbenzoic or 1-propylbenzoic acid.

However, where a sodium salt of an organic acid is employed, this is preferably sodium acetate, sodium 2-ethyl-hexanoate or sodium diethyl-acetate.

The basic salts with organic amino bases may be formed simply by the action of an appropriate organic amino base.

The salification of the syn isomers of general formula I to form basic salts is preferably carried out in a solvent or a mixture of solvents such as water, ethyl ether, methanol, ethanol or acetone.

The desired salts are obtained in amorphous or crystalline form according to the reaction conditions employed. For instance, when'preparing a metal salt, a crystalline product is preferably obtained by carrying out the salification with a salt of an aliphatic carboxylic acid mentioned above, and preferably with an acetate such as sodium acetate.

The derivatives of the parent invention that are acid addition salts of the syn isomers of general formula I may be prepared by simple reaction of an appropriate syn isomer with a mineral or organic acid, according to 0 6 4 8 - 23 conventional methods.

The syn isomers of general formula X that are esters may be prepared by esterifying the corresponding syn isomer wherein A represents a hydrogen atom. The esterification may be carried out under standard conditions In general the syn isomer is reacted with a derivative of formula Ζ-Εθ, in which Z represents a hydroxy radical or a halogen atom, such as fluorine, chlorine, bromine or iodine, and Εθ denotes the easily cleavable ester-forming group to be introduced.

Various of the syn isomers employed herein as starting materials may be obtained, inter alia, in the following manner: a) The syn isomers of general formula II'.

These may be prepared by treating a syn isomer of general formula V (which is described, inter alia, in French Patent No. 2,383,188), with 2-methoxypropene to obtain a syn isomer of the general formula: which syn isomer A, or a functional derivative thereof, - 24 such as the symmetric anhydride, is reacted with a compound of general formula IV to obtain a syn isomer of the which syn isomer B is treated with an aqueous mineral acid, such as dilute hydrochloric acid, to obtain the desired syn isomer of general formula II'. b) The syn isomers of general formula II.

These may be prepared by reacting a compound of formula Hal-CCHg^-Hal with an appropriate syn isomer of general formula II'. c) The syn isomers of general formula V.

These may be prepared by reacting a compound of formula Hal-CCHg^-Hal with an appropriate syn isomer of general formula V.

Some of the intermediates used in the preparation of the syn isomers of general formula I are themselves new compounds, and some of those compounds are the subject of the parent invention. Others, the oximes of formula III, and their production are the subject of the present invention. - 24(a) The derivatives of the parent invention possess good antibiotic activity against Gram positive bacteria, such as staphylococci and streptococci and especially against penicillin-resistant staphylococci. They also possess remarkable efficaey against Gram negative bacteria, especially against coliform bacteria and pseudomonas. - 25 These properties indicate the use of the derivatives of the parent invention as medicaments in the treatment of diseases in humans and animals caused bysensitive microorganisms, and especially in the treatment of staphylococcal infections such as staphylococcal septicaemia, malignant facial or skin staphylococcal infections, pyodermatitis, septic or suppurating sores, anthrax, phlegmons, erysipelas, acute primary or postinfluenzal staphyloccal infections, bronchopneumonia and pulmonary suppurations. They may also be used as medicaments in the treatment of colon bacillus infections and associated infections, in infections caused by Proteus, by Klebsiella, by Salmonella and by Pseudomonas and in other diseases caused by Gram negative bacteria.

Before using them as medicaments however, it is preferred to form the derivatives into pharmaceutical compositions, hy association with suitable pharmaceutical vehicles.

Accordingly, in a further aspect, the parent invention provides pharmaceutical compositions containing as active ingredient one or more syn isomers of general formula I and/or acid addition salts thereof with pharmaceuticallyacceptable acids, in association with a pharmaceuticallyacceptable vehicle.

The compositions preferably contain those derivatives mentioned hereinbefore as being preferred.

The description pharmaceutically-acceptable is used Γ - 26 10 herein to exclude any possibility that the nature of the vehicle or the acid, considered of course in relation to the route by which the composition is to be administered, could be harmful to the patient to be treated. The choice of a suitable vehicle or acid is believed to be within the competence of those accustomed to the preparation of pharmaceutical formulations.

The compositions can he administered by the buccal or rectal route, by a parenteral route or by topical application to the skin and mucous membranes. In respect of these routes the pharmaceutical vehicle is preferably: a) the ingestible excipient of a tablet or pill, such as a sugar-coated tablet; the ingestible container of a capsule or cachet, such as a gelatin capsule; the ingestible pulverulent solid carrier of a powder or granules; or the ingestible liquid medium of a syrup, solution, suspension or elixir; b) the solid or liquid medium of a paste, cream, ointment, gel or unguent; c) a sterile injectable liquid solution or suspension medium; d) a base material of a suppository; or e) the solid carrier of a soluble powder, which may be dissolved extemporaneously in an appropriate liquid, for instance apyrogenetic sterile water.

Whilst the pharmaceutical forms just listed represent those most likely to be employed, they do not necessarily - 27 exhaust the possibilities.

The vehicles employed will generally be those excipients commonly employed in the formulation of pharmaceutical compositions. Such excipients may be solid or liquid as appropriate to the pharmaceutical form chosen, and may include a wide range of organic and inorganic solids, and aqueous and non-aqueous liquids; examples include talc, gum arabic, starch, lactose, magnesium stearate orfetty substances of animal or vegetable origin such as cocoa butter, paraffin derivatives or glycols. These excipients may be compounded with one or more wetting, dispersing or emulsifying agents and/or one or more preservatives.

The dosage of the active ingredient to be administered to a patient will of course vary with the particular derivative concerned, the complaint and the patient being treated and the route of administration chosen. By way of illustration it may be said that a desirable dosage in an adult of the product of Example 1 or Example 9 hereafter would be from 0.25 g to 4 g administered daily by the oral route, or from 0.5 g to 1 g administered three times daily by the intramuscular route.

It will be appreciated from the foregoing that the derivatives of the parent invention may be used in a method of treating the human or animal body by therapy.

The derivatives of the parent invention may also however be used in a method of disinfecting an inanimate locus, for instance a 50S4B - 28 surgical instrument, in which, method the derivative is applied to the locus so as to disinfect the locus.

The specification of the parent application should he consulted for Examples of its pharmaceutical compositions and for a pharmacological study of its derivatives. r - 29 The following Examples illustrate the present compounds, their production, and their use as intermediates, and the production of the derivatives of the parent invention. Example 1: 3-acetoxymethyl-7-[2-(2-amino-thiazol-4-yl)5 -2-(2-amidinothio-ethoxyimino)-acetraido]-ceph-3-em-4-carboxylic acid trifluoroacetate, syn isomer.

Stage A: 2-£2-trij;y^amino-thi azol-A^yl)-2-(2-raidi.no_thi£-£thoxy£mino)-a£et:ic raid, syn isomer^ iri_the_form £f_an intern_al_salt.. por 27 hours, at ambient temperature and away from the light, a mixture of 4.6 g of 2-(2-iodo-ethoxyimino)-2-(2-tritylraino-thiazol-4-yl)-acetic acid, syn isomer, solvated with dichlorethane, 1 g of thiourea and 20 cm^ of hexamethylphosphorotriamide was agitated. The mixture was 35 then poured into 320 cm^ of isopropyl ether and the precipitated gum obtained was taken up with isopropyl ether then with water. The solid was separated, washed with water and dried to obtain 3.59 g of the desired product, M.Pt. - 260°C.

N.M.R. SPECTRUM (CPjCOgD) -CHgS- : triplet centred on 3-57 p.p.m. J · 6 Hz -N-0-GH2 : triplet centred on 4.72 p.p.m. J « 6 Hz Stage B: Benzhydr2l_32,acetox3me^h£l-7£[2-X.2-trityl25 -ceph-3~em-4-carboxylate hydriodide^,^sgn^irame r. .63 g of the product obtained above were agitated with 4.14 g of pyridine hydriodide, 8.24 g of dicyclohexyl50648 - 30 carbodiimide, 7 g of benzhydryl 7-amino-3-acetoxymethyl-ceph-3-em-4-carboxylate and 60 cnr of anhydrous dimethylformamide. After 25 minutes at 15°C, and 10 minutes at ambient temperature, the solid formed was separated by filtration, washing with methylene chloride. The methylene chloride was then driven off from the filtrate under reduced pressure at 45°C maximum, and the liquid residue was poured into 1 litre of isopropyl ether and agitated for 20 minutes, during which time a precipitate formed. The supernatant liquid was decanted away, and the precipitate taken up with isopropyl ether. The resulting suspension was then agitated for 20 minutes, and after decanting once more the precipitate was dissolved in methanol and re-precipitated with diethyl-ether. This was followed by agitation for a further 70 minutes, after which the precipitate was separated, rinsed with ether and dried to give 18.2 g of the desired product.

M.Pt. (decomposition):194°C.

Stage C: ac£t£xym ethy 1-^-^.2-(^-anino-thi a zpl-4-ilJ; ^2x(2-fflnidinothio.-£thoxyimino)xa£eiEmidp2-£e2hr3xem-47 -carboxylic acid trifluoroacetate, syn isomer. 7-5 g of the product obtained above and 75 g of trifluoroacetic acid were agitated together for 3 minutes at ambient temperature, after which the insoluble matter was separated by filtration and the filtrate recovered in 1.2 1 of chilled ether. After leaving for 15 minutes at ambient temperature, the precipitate formed was separated, dissolved in methanol and then re-precipitated by addition of diethyl ether. The whole was agitated for 15 minutes 80648 - 31 and the precipitate was separated, rinsed with diethyl ether and dried to give 2.19 Ε οΐ the expected product.

M. Pt. (decomposition) - 256°C.

N. M.R. SPECTRUM (CD^gSO -OAc : 2.02 p.p.m. singlet N-O-CHg- · 4.25 p.p.m.

H^ thiazole : 6.78 p.p.m. singlet I.R. SFECTRUM (Nujol, Nujol is a Trade Mark) β lactam : 1768 cm 10 Amide IX + heterocycle s 1538 cm”·'· U.V. SPECTRUM (EtOH,HCI N/10) max. 262 nm e| : 291 The 2-(2-iodo-ethoxyimino)-2-(2-tritylamino-thiazol-4-yl)-acetic acid, syn isomer, used at the start of Stage A above, is described in Belgian Patent No. 875,217· Example 2; 3-ecetoxymethyl-7-C2-(2~amino-thiazol-4-yl)-2-(2-amidinothio-ethoxyimino)-acetamido]-ceph-3-em-4-carboxylic acid trifluoroacetate, syn isomer.

Stage A: Benzhydi£l_3xa£et03^e£hjl27-[2-£2-tri.tylamiino-£h^a-zoil-4-i2l2-2-X2-Midinothio-eth£X2imino27 -acetamido]-ceph-3-em-A-carboxylate hydriodide, syn isomer.

For 32 hours, 870 mg of benzhydryl 3-acetoxymethyl-7-C2-(2-tritylamino-thiazol-4-yl)-2-(2-iodo-ethoxyimino)-acetamido)-ceph-3-em-4-carboxylate, syn isomer, 131 mg of thiourea and 1.7 cm^ of anhydrous hexamethylphosphorotriamide were agitated together. Then, whilst continuing to agitate, 75 cm^ of isopropyl ether were added, followed, after decanting, by 45 cm^ of diethyl ether. The precipi- 32 OAc ch2s och2 CHg OAc was separated to obtain 1.229 g of the solvated desired product. M.P. 100°C.

N.M.R. SPECTRUM (CDCl^ 2.0 p.p.m. singlet from 3·33 to 5·83 p.p.m· 4.5 p.p.m. 4.88 - 4.98 p.p.m.

H at position 6 : doublet 5·14· p.p.m. J = 5 Hz H at position 7 : 5·θ3 ~ 6.08 p.p.m.

H at position 5 : (thiazole : syn) 6.78 p.p.m. singlet Stage B;_ ^-ac_etex2methyl-2.-£2x(2-amino.-thiazpl.-4-ilJ; £2y.(2-fflJiidinothi£-ietho3gn1mino)xacetamid.o2-ce£h3.3z.eS-Ii'' -carboxylic^ acid_t£ifkioroacetate, syn i-somer^ For 3 minutes and at ambient temperature, 4-50 mg of x the product obtained in Stage A of this Example, and 4.5 cnr of trifluoroacetic acid were agitated together. At the end of that time, the insoluble matter was separated by x filtration, and the filtrate recovered in 4-5 cm' oi chilled diethyl ether. The whole was agitated for 15 minutes, before separating the precipitate, rinsing it x with diethyl ether and taking it up m 0.8 cnr of methanol. Then, after adding 8 cm^ of diethyl ether and agitating for a further 15 minutes, the precipitate was separated, rinsed with diethyl ether and dried to give 100 mg of product.

M.Pt. (decomposition) 256-258°C.

N.M.R. SPECTRUM (CD,)„SO - 5 d OAc : 2.02 p.p.m. singlet S0648 - 33 proton at 5 of the thiazole : 6.77 p.p.m. singlet I.R. SPECTRUM (Sujol) β lactam 1769 cm~^ Amide II + heterocycle : 1554 cm-1 U.V. SPECTRUM (EtOH HCl N/10) Max. 259 nm E^ - 327 The benzhydryl ester of 3~acetoxymethyl-7-C2-(2-tritylaaino-thi azol-4-yl)-2-(2-iodo-ethoxyimino-acetamido 3-ceph-3-em-4-carboxylic acid, syn Isomer, used in Stage A of this Example, is described in Belgian Patent No. 875,217. Example 5: 5-acetoxyaethyl-7-i2-(2-aininothiazol-4-yl)-2-(2-aaidinothio-ethoxyimino)-acetamido]-ceph-3-em-4-carboxylic acid hydriodide, syn isomer.

For 36j hours a mixture of 130 mg of 3-acetoxymethyl15 -7-[2-(2-amino-thiazo1-4-yl)-2-(2-iodo-ethoxyimino)-acetamido]-ceph-3-em-4-carboxylic acid trifluoroacetate, syn isomer, 28 mg of thiourea and 0-37 cm^ of dimethylformamide was agitated at ambient temperature. A gummy z precipitate was thrown down by the addition of 3 cm of isopropyl ether, and after decanting the gum was taken up with isopropyl ether, then with diethyl ether and finally with ethyl acetate. After separating the formed precipitate, washing it with ethyl acetate and drying, 133 ag of an impure product was obtained which was purified in ethyl acetate to give 85 mg of the expected purified product.

M.Pt. oi250°C. - 34 ~ N.M.H. SPECTRUM (CD^SO OAc : 2.02 p.p.m. singlet N-O-CHg- : triplet 4.28 p.p.m. J = 6 Hz H at position 6 : doublet 5.16 p.p.m. J = 5 Hz Ξ at position 7 : 5-68 to 5.88 p.p.m.

Proton at 5 of the thiazole : 6.82 p.p.m. singlet.

U.V. SPECTBUM (EtOH HCl N/10) Maximum at 220 nm Ej = 444 ε 29^800 Inflection at 255 nm E| = 262 e 17^600 3-acetoxymethyl-7-[2-(2-amino-thiazol-4-yl)-2-(2-iodo-ethoxyimino)-aeetamidc3-ceph-3“em-4-carboxylic acid trifluoroacetate, syn isomer, used at the start of this Example, is described in Belgian Patent No.875,217Example 4: 3~(1-methyl-lH-tetrazol-5-yl-thiomethyl)-715 -[2-(2-aminothiazol-4-yl)-2-(2-amidinothio-ethoxyimino)-acetamido]-ceph-^-em-4-carboxylic acid, syn isomer, in the form of an internal salt.

Stage A: ^-£.l£m£thylf-J.H-t£t£a£Ol-J^2l£thiomethyl)£ -7£.[2-£2-tritylaminothi.a£ol-4-j;l£--2-^2£ami^inqthi.02.ethox2;20 imino)-acetamido]-ceph-3-em-4-carboxylic acid, syn isomer, £n_the_form of_an j.nternal_salt.

A mixture of 660 mg of 7-amino-3-(l-methyl-lH-tetrazol-5-yl-thiomethyl)-ceph-3-em-4-carboxylic acid and 10 cm^ of anhydrous dimethylformamide was agitated for io minutes and then cooled to +15°C before the addition, in several portions over 5 minutes and under agitation, of 260 mg of triethylene diamine. After 3 minutes, 1.68 g - 35 of pyridine hydriodide were quickly added, and the whole was agitated for 2 minutes. 1.06 g of 2-(2-tritylamino-thiazol-4-yl)-2-(2-amidinothio-ethoxyimino)-acetic acid, syn isomer were then added, and after agitating for 5 minutes, 840 mg of dicyclohexylcarbodiimide were added, all at once and at 15°C. The whole was left for 45 minutes, before filtering off the formed precipitate and pouring the filtrate into 250 cm^ of iced water.

After agitating for a further half an hour, the solid formed was separated, washed with water and dried to give 1.338 g of an amorphous product. 1.23 g of this was purified by agitating for half an hour with 10 cm^ of methylene chloride, filtering off the insoluble matter, treating the filtrate with active charcoal, filtering off the solid and concentrating the filtrate to dryness to give 857 mg of the desired product.

N.M.R. SPECTRUM (CD^gSO -N-CH^ : 3.9 p.p.m.

Protons of the trityl : 7·? p.p.m.

I.R. SPECTRUM (CHCl^) β lactam : 1769 cm-1 Amide : 1674 cm”1 COg” + aromatic : 1600 cm”1, 1493 cm-1 Amide II + heterocycle : 1525 cm 1 P.V. SPECTRUM (EtOH HCl N/10) Max. 271 nm · e} = 230 50848 ( - 36 Stage. fl: l-i.lfl.ine,thyl.-].H-t£tra£Ol-5-vl-thi£inethyl)£. a.7flt£-£2-anino_thi.a£ol.-4-2l2-2-£22.amidi£OjtIiio-eth.£X2imino}_-acetamido]-ceph-3-em-4-carboxylic acid,_sjgn_isomer, in It he ar^int^nal, 800 mg of the product obtained from Stage A of this Example were dissolved in 8 cm^ of 92% aqueous acetic acid by heating to 48°-50°C, and the solution was maintained at this temperature for 2^ hours. The insoluble matter present was separated by filtration, and to the filtrate was added 150 cm^ of isopropyl ether. The whole was then agitated for half an hour, and allowed to stand for one hour, after which the precipitate was separated by filtration, washed with isopropyl ether then with ethyl ether, and dried to give 537 mg of product. This was purified by agitating for half an hour with 2 cnr of ethanol, then with 2.5 cm^ of water, to give 325 mg of 3 product, which in turn was taken up with 2 cm of acetic 3 3 acid. 20 cnr of methanol and 4 cnr of water were then added drop by drop, and after agitating for half an hour, filtering, treating the filtrate with active charcoal, filtering again and evaporating the filtrate to dryness, a residue was obtained, which was taken up several times with ethanol. Finally, 175 mg of white product were obtained. M.Pt.ci 258°C.

N.M.R. SPECTRUM (CD^gSC Proton at 5 of the thiazole (syn) 6.82 p.p.m. singlet N-CHj : 3.92 p.p.m. - 37 N-OCHg and CH^-S- : 4.33 p.p.m.

H of the β lactam tut 5 to 5.83 p.p.m.

I.R. SPECTRUM (Nujol) β lactam 1766 cm-1 G amide II 0 1667 cm-1 CO^ 1597 cm1 Amide II : 1533 cm U.V. SPECTRUM (EtOH HCl N/10) Infl. 223 nm E1 = 338 Max. 263 E1 - 295 Infl. 280 nm Ε1 » 255 Example 5' 3~azidomethyl-7-[2-(2-aminothiazo1-4-yl)-2-(2-amidinothio-ethoxyimino)-acetamido]-ceph-3-em-4-carboxylic acid, syn isomer, in the form of an internal salt.

Stage. A: ^-azi.domethyl-2-X2-(2-^rit2;lemin£thiaz£l-4^yl)2.2£(2~amidi.n£thi£-eth.03tyimino)-a£et-amidoJ-£e£h^3-em-_ -4-carboxylic acid, syn isomer, in the form of an internal salt^ For 15 minutes, 255 mg of 7~amino-3-azidomethyl3 -ceph-3-em-4-carboxylic acid were agitated with 3 cnr of anhydrous formamide and then, in a number of portions, 168 mg of triethylenediamine were added. 412 mg of pyridine hydriodide were added to the solution obtained, and the whole was cooled to +15°C before the addition of a 5Θ648 - 38 solution comprising 532 mg of 2-(2-tritylamino-thiazol-4-yl)-2-(2-amidinothio-ethoxyiraino)-acetic acid, syn isomer, 207 ag of pyridine hydriodide and 3 cm^ of dimethylformamide, immediately followed hy 412 mg of dicyclohexylcarbodiimide.

The whole was then agitated for 20 minutes at 15°C then for 40 minutes at 20°C, and the solid present was removed z by filtration. 100 cur of water were added to the filtrate, and after agitating for half an hour, leaving to stand for half an hour, and separating,washing with water and drying the precipitate, 437 mg of crude product were obtained. Of this 432 mg were purified by agitating with 8.6 cm^ of chloroform for half an hour, removing the solid present by filtration, treating the filtrate with active charcoal, removing the charcoal and evaporating the solvent to give 350 mg of the desired product.

I.a. SPECTRUM (CHCl^) Azide : 2160 cm β-lactam : 1769 cm Amide : 1670 cm 00θ : 1600 cm-1 Amide II : 1521 cm1 Stag£ B: ^.-£zidomethyl-2.-X2£(2-aminothiaz£l24-yl)2. -2^(2^-ami_d£nothi£-£thoxyimi.no.)2.acet.amid.o_]_-c.e£h£32.em-4-_ -carboxylic acid, syn isomer, in the form of an internal salt. 344 mg of the product obtained in Stage A of this Example and 3»5 cm^ of 92% acetic acid were heated to - 39 46-50°C for 2 hours 15 minutes. The whole was treated with active charcoal and heated for a further 30 minutes before the solid was removed by filtration with heating. cm^ of diethyl ether were added to the filtrate, and after standing for 15 minutes, the formed preceipitate was separated and washed with diethyl ether to give 159 mg of the desired product.

M.Pt 238°C.

N.M.R. SPECTRUM (CDj^SO Proton at 5 of the thiazole s 6.8 p.p.m. singlet H at position 6 : doublet 5-06 p.p.m. J » 5 Hz H at position 7 ; after treatment with DgO doublet 5*67 p.p.m. J » 5 Hz I.R. SPECTRUM (Mujol) and β-lactam 1770 cm C amide 1667 cm N5 ) 2102 cm ®2Θ) C-C .-1 1600-1535 cm .-1 U.V. SPECTRUM (EtOH HCl N/10) Infl. : 222 nm E1 - 325 Max. : 261 nm E1- 319 Infl. : 280 nm 4 - 271 Example 6; 3~(2-nethyl-l,3,4-thiadiazol-5-yl-thiomethyl)-7-[2-(2-aminothiazol-»-yl)-2-(2-amidinothio - ethoxyimino)-acetamido]-ceph-3-em-4-carboxylic acid, syn isomer, in the form of an internal salt S48 - 40 Stage A: ^-^2-m£thyl-i,J.,4-thiadirao.l-52yl,-ihiomet^h2]j2 ^/-Ε^-^-ΐΓίΐτΙεωΐηο^ΐβΜΐ.-^-^Ώ.τΖ-ί.^-βηϊά.ίηοίΙιϊο-β^οχχimino) - ac e t amidoJ_~ c eph-3£em-4- c ahboxylic_acid ,_sjn_isome r, ,in_the_form of_sn ipternal_sal£.

For half an hour, 207 mg of 7-amino-3-(2-methyl-1,3,4-thiadiazol-5-yl“thiomethyl)-ceph-3-em-4-carhoxylic acid and 1.8 cm'’ of dimethylformamide were agitated together. Then, at 15°C and in a number of portions, mg of triethylene diamine were added, followed by 252 mg of pyridine hydriodide and then quickly by the solution obtained by agitating together 318 mg of 2-(2-tritylamino-thiazol-4-yl)-2-(2-amidinothio-ethoxyimino)acetic acid, syn isomer, 252 mg of pyridine hydriodide and 1.8 cm^ of dimethylformamide. 252 mg of dicyclohexylcarbodiimide were then immediately added, and the whole was agitated for 15 minutes at 15°θ, and for 30 minutes at °C, before removing the insoluble matter present by 3 filtration. To the filtrate were added 120 cnr of water and the whole was agitated for 15 minutes, after which the precipitate formed was separated, washed with water and dried to give 361 mg of crude product. This was then agitated for half an hour with 20 cm^ of methylene chloride, the insoluble matter present was removed by filtration, and the filtrate was concentrated to dryness.

The residue was taken up with chloroform and treated with active charcoal, which was afterwards removed by filtration.

The filtrate was then brought to dryness under argon to 80648 - 41 give 1?1 mg of the expected product.

I.R. SPECTRUM (Nujol) β-lactam : 1764 cm-·'’ Amide : 1667 cm-1 Aromatic and C0^ : 1599 cm\ 1497 cnT^ Amide II + heterocycle : 1526 cm-1, 1511 om“^ U.V. SPECTRUM (EtOH HCI N/10) Max. 271 nm e} - 227 ε - 19,500 Stage. B: £-£23m£thy]L-l.,^,4-thiadiaz£l-5r7A-lhi.ometh2l2-7st2-£2-aminothi.a£ol-4-2l2-2-£2-amidinothi.o^eth£X2inino2.-_ -acetamido]-eeph-3-em-4-carboxylio acid, syn isomer, in the form_of an_int ernal. .salt.

For 2^ hours and under agitation, 171 mg of the product obtained in Stage A of this Example and 1-71 cm^ of 92% acetic acid were heated together at 48°C-50°C, after which the solution obtained was filtered. 30 cm^ of isopropyl ether were added to the filtrate, and after agitating for 15 minutes and then leaving to stand for minutes, the precipitate formed was separated, washed with isopropyl ether then with diethyl ether and dried to give 93 mg of the expected product. M.Pt.Oi 260°C.

N.M.R. SPECTRUM (CD,)oS0 // 52 CH^-C · 2.67 p.p.m. singlet N-OCHg and CHgS (at 3) : 4.33 p.p.m.

H at positions 6 and 7 : 5.0 to 5.83 p.p.m.

H^ of the thiazole : 6.78 p.p.m. singlet Ο 6 4 8 - 42 I.R. SPECTRUM (Nujol) 0-lactam 1760 cm Amide 1660 cm C02 1613-1595 cm-1 Amide II + heterocycle 1531 cm U.V. SPECTRUM (EtOH HCl N/10) Infl. 220 nm E^ = 312 Max. 265 nm E* = 307 Infl. 280 nm E* = 278 Example 7'· 3~acetoxymethyl-7- C2-(2-aminothiazol-4-yl)-2-(2· -thiocyanato - ethoxyimino)-acetamido]-ceph-3-em-4^ -carboxylic acid, syn isomer.

Stage A: ^-^.2£t£i£ylamino£thi£Z£l-42yi)£.2£(^-thip£ cyanato-ethoxyimino)-acetic acidj. syn. isomer^ For 139 hours, at +15°C and away from the light, 6.83 g of 2-(2-iodo-ethoxyimino)-2-(2-tritylamino-thiazol-4-yl)-acetic acid, syn isomer, solvated with dichlorethane z 7.61 g of ammonium thiocyanate and 35 cnr of dimethylacetamide were agitated together. The resulting solution was cooled in a bath of iced water before adding 400 cm^ z of distilled water then 150 cnr of a saturated solution of sodium chloride. The whole was agitated for 2 hours, and the formed precipitate was then separated, washed with water and dried to give 4.55 S o£ crude product.

After two recrystallisations from ethyl acetate, 3.44 g of the expected product were obtained. M.Pt. = 194°C. - 43 Stage B: Benzhydr2l_3^.acet^oxyme£h2l£7£[2-^2£tr.ityl·amin£thiaz£lx42jyi)2.2x(2-thiocyMato-ethoxyimino)£ -acetamidol-ceph^-em-^carboxylate^ spm is£,m£rj. 1.69 g of the product obtained in Stage A of this Example were mixed with 0.685 g of pyridine hydriodide, 1.16 g of benzhydryl 7-amino-3-acetoxymethyl-ceph-3-em-4-carboxylate and 1.36 g of dicyclohexylcarbodiimide. cm^ of dimethylformamide were immediately added, and the whole was cooled to 16°C for 30 minutes, after which z the insoluble matter was removed by filtration. 400 cnr of diethyl ether were added to the filtrate, and after agitating for 5 minutes then leaving to stand for one hour, the gum obtained was isolated by decanting., and washed with diethyl ether. 5θ cm^ of diethyl ether were added to the gum, and the whole was mixed until a solid precipitate appeared. This was then separated, washed with diethyl ether and dried to give 1.92 g of crude product, which was purified by chromatography on silica, eluting with a chlorof orm/acetonitrile mixture (91·'9). 790 mg of amorphous product were obtained.

N.M.R. SPECTRUM (CDCl,) OAc : 2.0 p.p.m. singlet the CHg-S’s : 3-17 to 3.65 p.p.m.

N-0-CH2 : triplet 4.58 p.p.m. J « 6 Hz CHg-OAc : 4.65-4.87 p.p.m. and 4.98-5-2 p.p.m. thiazole ato : 6.77 p.p.m. singlet ( · ,· 5 0 6 4 8 - 44 I.B. SPECTRUM (CHCl^) C=N : 2156 cm-1 β-lactam 1793 cm-1 ester + OAc : 1739-1733 cm · amide : 1689 cm U.V. SPECTRUM (EtOH HCl N/10) Max. 267 nm E^ = 209 ε » 1%540 Stage C: £-£C£t£X2m£thyl.-2-_[2£(^-amin£th,i£Z£l£4£yl) -2-(2-thiocyanat£-etho3£yimino)£acetamido2-£e£h23-®S.-4-_ -carboxylic ac£dj_ syn isomer. 445 mg of the product obtained in Stage B of this z Example and 4.4 cur of trifluoroacetic acid were agitated x together for 3 minutes at ambient temperature. 44 cm of chilled isopropyl ether were then added, and after 15 agitating for 5 minutes the formed precipitate was separated, rinsed with an isopropyl ether/diethyl ether mixture (1:1), then with diethyl ether alone, and redissolved in 0.8 cm^ of methanol. 8 cm^ of diethyl ether were added to the solution and the whole was agitated for 20 10 minutes. Finally, the formed precipitate was separated rinsed with diethyl ether and dried to give 199 mg of the expected product. M.Pt. (decomposition)^ 200°C.

N.M.R. SPECTRUM (CDj^SO OAc : 2.03 p.p.m. singlet the CBgS's : 3·17 to 3«83 p.p.m.

H^ thiazole syn : 6.82 p.p.m. singlet - 45 I.a. SPECTRUM (Nujol) S-CsN : 2153 cm-1 β-lactam : 1781 cm 1 U.V. SPECTRUM (EtOH HCl N/10) Max. 264 nm ε 18,900 Example 8: 5~acetoxymethyl-7f2-(2-aainothiazol-4-yl)-2-(2-N1-aminoamldinothio-ethoxyimino)-acetamidol-ceph-3-em-4-carboxylic acid, syn isomer, in the form of an internal salt.

Stage A: 2-_£2-tritylami£0£thiaz£lx4^yl)-2-C2-£N^-tritylamino-amidinothio)-ethoxyimino]-acetic acid, syn is£m£rj_ in_the_f£rm £f_an internal_salt.. 7.5 g of 2-(2-iodo-ethoxyimino)-2-(2-tritylamino-thiazol-4-yl)-acetic acid, syn isomer, solvated with dichloroethane, and 13.5 g of l-trityl-thiosemicarbazide were dissolved in 45 cm^ of anhydrous dimethylformamide. The solution was heated to 3O-32°C, away from the light and for 65 hours, and then poured into 900 cur of water. The whole was agitated for 10 minutes before adding 60 cm^ of saturated solution of sodium chloride and, after half an hour, the precipitate formed was separated, washed with water and dried to give 18.14 g of crude product. 5 g of this was purified by chromatography on silica, eluting with a chloroform/methanol mixture (85:15), and then taken up with isopropyl ether and dried to give 1.44 g of the expected product. M.Pt.-ϊί200°C. (' - 5 0 6 4 8- 46 N.M.R. SPECTRUM (CDCl^) thiazole : 5·87 p.p.m. singlet N-O-CHg : 4.33 p.p.m.

H of the trityls : 7.18 - 7-35 p.p.m. labile H : 5.42 p.p.m.

I.R. SPECTRUM (CHClj) NH : 3,392 cm'1 U.V. SPECTRUM (EtOH HCl N/10) Max. 278 nm E^ = 180 Stage B: Benzhydrjl_3~ace-toxymeth2lx7z(2-£2-trityl-_ -£®ϊηο£Ϊ1ιΐαζ£ΐ£4^^-^(^-χΝ2;-ΐΓΐΛ2ΐΜΐ1ηο-Μΐίά±ιιο^ίο,)-ethox2imino2-ace_tamido]-ceph-2yem2.4-carboxylate_h2dri£di.d£, syn isomer.

Por 20 minutes and at ambient temperature, 513 mg of the product obtained in Stage A of this Example, 134 mg of pyridine hydriodide, 268 mg of dicyclohexylcarbodiimide, 227 mg of benzhydryl 7-amino-3-acetoxymethyl-ceph-3-em-4x -carboxylate and 3 cnr of anhydrous dimethylformamide were x agitated together. 10 cm of methylene chloride were added to the whole, the dicyclohexylurea formed was separated hy filtration, and the filtrate was concentrated under reduced pressure. The residue was then agitated x with 40 cnr of isopropyl ether for 5 minutes, and the resin x obtains! was isolated hy decanting, taken up with 40 cm of an isopropyl ether/diethyl ether mixture (1:1), triturated, agitated for 20 minutes, separated, rinsed with isopropyl ether and dried to give 680 mg of the expected product.

M.Pt. (decomposition) 162°C. ( · - 47 I.B. SPECTRUM (CHClj) NH : 3391 cm1 C=0: 1782 cm1 Ester and OAc ί 1736-1730 cm 1 5 Aromatics : 1594 cm-1, 1576 cm1, 1496 cm Stage C: ^,-ac£t£X2m£thyl-2i2-£2^imino-thiaz£l-4z7l.)3. -2-( 2-lN^-amin£-am^di.n£thi£)-eth£x^iminp2.-ac£tamid£3-c£ph-2-em-4-carboxylic acid_j_ syn isomer^ in_^Me_f£r£ £.f_ an_ internal, s,alt_j_ For 45 minutes and at 50°C, 0.94 g of the product obtained in Stage B of this Example, 9·4 cm^ of formic acid and 4.7 cm^ of water were agitated together. The whole was then cooled to ambient temperature before removing the insoluble matter present by filtration and concentrating the filtrate to dryness. The formed residue was taken up with 9 cm^ of trifluoroacetic acid and agitated for 4 minutes, after which the insoluble matter was removed by filtration. 90 cm^ of isopropyl ether were added to the filtrate, and after agitating for 5 minutes the formed precipitate was separated, rinsed with isopropyl ether, taken up with a minimum of methanol and re-precipitated with diethyl ether to give 282 mg of crude product. 558 mg of this was put into suspension in 7 cm^ of water, and pyridine was added until a pH of 6.6 was reached. The slight amount of insoluble matter present was then removed by filtration, and the filtrate was concentrated to dryness under reduced pressure to give a residue. This was taken - 48 up with 5 cm^ of diethyl ether and triturated, and the precipitate thus obtained was separated and rinsed with diethyl ether to give 500 mg of impure product. This was agitated for 10 minutes in 5 cm^ of methanol, separated, and made into a paste with ethyl ether. 96 mg of the expected product were then obtained. M.Pt. (decomposition) 210°C.

From the mother liquors an additional 66 mg of identical product were obtained.

N.M.R. SPECTRUM (CD^SO OAc : 2.03 p.p.m. singlet N-O-CHg = 4.25 p.p.m.

H,. of the thiazole : 6.78 p.p.m. singlet U.V. SPECTRUM (EtOH-HCl N/10) Max. 262 nm E^ = 301 ε = 16,800 The 1-trityl-thiosemicarbazide used at the start of Stage A of this Example was prepared as follows: Uhilst agitating, 100 cm^ of dimethylacetamide were quickly added to 9.11 g of thiosemicarbazide and 27.9 g of trityl chloride. The whole was maintained at a temperature of +15°C, then, drop by drop, 13 cm^ of triethylamine were added. The resulting solution was then left for one hour at 15°C before adjusting the pH to about 7 with triethylamine, and then pouring into a 2 litre mixture of water and ice. After agitating for half sn hour, the precipitate obtained was separated, washed with water and dried at 50°C under reduced pressure to give (CHC15) 3505 cm-1 (EtOH.HCl N/10) - 49 31.3 g of an impure product. M.Pt. - 194°C. 29.3 g of this was agitated for half an hour with 90 cm^ of ethyl acetate, and then separated, washed with ethyl acetate and dried to give 25.05 g of product. M.Pt. - 208°C.

N.M.R. SPECTRUM (CDCl^) labile H’s : 5-08 p.p.m. 6.92 p.p.m. 6.33 p.p.m.

H of the trityl :2(7.33 p.p.m.

I.R. SPECTRUM -c-nh210 H-V- SPECTRUM Max. 245 nm E* . 405 Example 9: 3-aaetoxymethyl-7-[2-(2-amino-thiazol-4-yl)-2-difluoromethoxyiaino-acetamido]-ceph-3-em-4-carboxylic acid, syn isomer.

Stage A: Ethyl 2-£2£tritylamino~thiazol-4^yl)^2-difluoromethoxyimino-acetate, syn isomer.

For 5 minutes, 3 g of ethyl 2-hydroxyimino-2-(2-tritylamino-thiazol-4-yl)-acetate hydrochloride, syn isomer, 20 cm^ of 2N sodium hydroxide and 20 cm^ of 100° ethanol were agitated together. The sodium salt precipitated, and was dissolved by the addition of 60 cm^ of dioxan. Monoehlorodifluoromethane was bubbled through the solution for 30 minutes, under good agitation, after which 20 cm^ of 2N sodium hydroxide, 20 cm^ of 100° ethanol and 60 cm^ of dioxan were added. The bubbling-in of monochlorodifluoromethane was then continued for a further 30 minutes, before adding 6.7 g of sodium bicarbonate. The whole was agitated for 15 minutes at ambient temperature and the slight amount of insoluble matter present was removed by filtration. The filtrate was concentrated under reduced pressure at a temperature not exceeding 4O°C until a syrup-like consistency was obtained, at which point chloroform was added. After decanting, washing the decanted solution once with water then with a saturated aqueous solution of sodium chloride, drying, evaporating to dryness and chromatographing on silica (eluting with benzene) 652 mg of a resinous white product were obtained.

N.M.R. SPECTRUM (CDCl^) CH P2 : 5-55 - 6-75 - 7-95 p.p.m. Η<- thiazole syn : 6.77 p.p.m. singlet U.V. SPECTRUM (EtOH) Max. 308 nm E^ = 80 e = 4100 I.R. SPECTRUM C=N0R 1141 cm-1 CHP2 = 1145 cm1 “ 1117 cm1 Stage B: 2-£2-trityl.amino£thi£Z£l£4£yl)£22.(difluo£O£ methoxyirainoL-acetic acid,_s£n_isomer. 51 mg of the product obtained in Stage A of this Example, 0.05 cm^ of dioxan, 0.35 cm^ of 100° ethanol and 0.1 cm^ of IN sodium hydroxide were agitated together. A slight amount of gum was formed, and this was dissolved with x 0 0.1 cnr of 100 ethanol. The reaction containerwas then 25 stoppered hermetically and heated to 40°C for 2^ hours before being left for one night at ambient temperature under vigorous agitation. The precipitate formed was - 51 separated and rinsed with a few drops of a dioxan/ethanol mixture (1:7), then with ether, to give 25 mg of the Na salt. This was taken up in 1 cm^ of chloroform and 1 cm^ of water, and IN hydrochloric acid was added until pH 2. After agitating vigorously, the chloroform was decanted, washed with water, dried and evaporated to dryness to give 16 mg of white resin.

N.M.R. SPECTRUM CDClj CHF2 : 5·4 - θ·δ - 7-8 p.p.m.

H^ thiazole syn : 6.72 p.p.m. singlet OH and MH’ : 9·33 and 10.25 p.p.m.

Stage 0: Te£t2but2l„3£a£eto2OTei^kL7sQ2-£2£t£ity.l-_ amino-thi.azioli-4-£l^.-2.-difluo£ometh£X2iimino2.acetiamidoJ.-ceph-3-em-4-carboxylate, syn isomer.

In a bath of ice, 820 mg of product obtained as in Stage B, 492 mg of tert-butyl 3-acetoxymethyl-7-amino-ceph-3-em-4-carboxylate and 16 cm^ of chloroform were agitated together. Then, drop by drop, 2 cm^ of a chloroform solution containing 390 mg of dicyclohexylcarbodiimide were added, and the whole was left for one and a half hours at ambient temperature^. The solid dicyclohexylurea formed was removed by filtration and the filtrate was evaporated under reduced pressure and chromatographed on silica, eluting with a methylene chloride/ethyl acetate mixture (94:6), to give 57^ mg of white resin.

N.M.B. SPECTRUM (CDClj) tert-butyl : 1.54- p.p.m. singlet ί - 52 OAc : 2.0 p.p.m. singlet CHF-. : 5-6 6.8 - 8i0 p.p.m.

CS c.

H<_ thiazole syn : 6.92 p.p.m. singlet U.V. SPECTRUM (EtOH HCl N/10) Max. 262 nm E^ =» 21? Stage D: 2.-ac£t£3q2m£thyl~2-X2-(2-amino-thla£O_l2^Α^1)-2-άΐίχη£ΓθΒ£ΐΗ°Χ3^ιηϊηο.-βοβΐ amido Ixceph-^yenr/t. -carboxyli£ £cidj_ syn isomer^ For 3 minutes and at ambient temperature, 0.32 g of the product obtained in Stage C of this Example and 1.6 cm^ of pure trifluoroacetic acid were agitated together. The whole was poured into 16 cm of a chilled mixture of isopropyl ether and ethyl ether (1:1) and agitated for 15 minutes. The resulting precipitate was then separated, rinsed with the above ethereal mixture, then with pure diethyl ether, to give 130 mg of white product. M.Pt. (decomposition)'X 176°C.

N.M.R. SPECTRUM (CD^SO OAc 2.03 p.p.m. singlet CHF2 : 5.95 - 7.13-8.23 p.p.m.

H^ thiazole syn : 7·θ5 singlet U.V, SPECTRUM (EtOH HCl N/10) Max. 278 nm E1 = 265 I.R. SPECTRUM (Nujol) β-lactam : 1777 cm1 OAc : 1726 cm1 -C=NOR : 1031 cm1 80648 - 53 Derivatives of the parent invention corresponding to those prepared in the above Examples but wherein represents a hydrogen atom, may be prepared by methods directly analogous to those set out in the Examples.

Claims (11)

1. An oxime of the general formula: syn isomer, 5 wherein R'g represents a hydrogen atom or a protecting group; and R represents the radical -CHKg or the radical -(CHg) n -S-R c in which n represents an integer of 1 to 4 and 10 βθ represents the radical -C(=NH)-NHgj the radical -C(-NH)-NH-NH-R^ or the cyano radical, where R^ represents a protecting group.

2. An oxime according to claim 1 wherein R represents the radical -CHFg. 15 3„ An oxime according to claim 1 wherein R represents the radical -(CH O ) -S-R » 2 n c An oxime according to any one of the preceding claims wherein R’g and R 4 are the same or different and represent trityl, chloroacetyl, tert-pentyloxyearbonyl, tert-butyloxycarbonyl or benzyloxycarbonyl.

3. 5. An oxime according to any one of claims 1-3 wherein R'g represents a hydrogen atom.

4. 6. An oxime according to claim 2 wherein R'g represents a hydrogen atom or a trityl radical.

5. 7. Process for the preparation of an oxime claimed in claim 1 wherein R represents the radical -(CH 9 ) -S-R , £>12 C which process comprises reacting a syn isomer of the general formula wherein R'g and n as defined in claim 1; and Hal represents a halogen atom; with SO 04 8 - 56 (a) a compound of the formula in which R^ represents a protecting group, (b) a compound of the formula N=G-S-R^ in which 5 R^ represents an ammonium group or an alkali metal atom, or (c) thiourea.

6. 8. Process according to claim 7 wherein Hal represents a bromine or iodine atom.

7. 9. process for the preparation of an oxime claimed in 10 claim 1 wherein R represents the radical -GHFg, which process comprises reacting a syn isomer of the general formula: wherein R'g is as defined in claim 1 with a compound of the 15 formula Halx-CHPg wherein Hal^ represents a chlorine or 50848 - 57 bromine atom.

8. 10. Process according to claim 9 wherein the reaction is carried out in the presence of a mineral base.

9. 11. Process according to claim 9 or 10 wherein the 5 reaction is carried out in an anhydrous organic solvent.

10. 12. Process for the preparation of an oxime claimed in claim 1, which process is performed substantially as described herein.

11. 13. Process for the preparation of an oxime claimed in 10 claim 1, which process is performed substantially as described herein with reference to any one of the Examples.