IE41590B1 - Novel cephalosporin compounds - Google Patents

Abstract

Novel cephalosporins of the general formula are obtained by reaction of a 3-acetoxymethylcephalosporin of the formula with a triazinylthio derivative of the formula The substituents are defined in Claim 1. If necessary, the amino and/or carboxyl groups are intermediately protected and, if it is desired, the compounds obtained according to the invention are acylated by the known processes. The reaction is preferably carried out in polar solvents, e.g. water. These novel cephalosporins are to be used on the one hand as medicines having antibiotic activity or on the other hand as intermediates in the preparation of antibiotics.

Description

The present invention relates to a new class of cephalosporin compounds having in the 3-position a '-oxo-6hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthiomethyl group and ft · to a process for the preparation thereof. These compounds 5 have excellent broad spectrum gram-positive and gramnegative antibiotic activity. Compounds of this general, type are described and claimed in the specification of Patent ApplicationiNo. 1366/75.

The present invention provides novel cephalosporin compounds of the formula I in which R^ is hydrogen or lower alkyl; R2 is hydrogen, an alkali metal cation, or a readily removable ester forming group; and R is hydrogen or the group R'-C- in which R· is hydrogen; C^-Cg alkyl; C-^-^ haloalkyl; C^-Cj cyanoalkyl; Ci-C3 a2idoalkvl; C-^-Cj hydroxyalkyl; p-nitrobenzyloxy„ 4-amino-4-carboxybutyl; a 4-substituted-amino-4-ost A-O-C-CH-(CH ) -CH I 2 z s NH I A' • in which A is diphenylmethyl, p-nitrobenzyl, benzyl, 2,2,220 trichloroethyl, t-butyl, or p-methoxybenzyl, and A' is -241590 C2~C4 alkanoyl, C2-C4 haloalkanoyl, benzoyl, halobenzoyl, 2,4-dinitrophenyl, or phthaloyl? or R' is a group of the formula in which a and a' independently are hydrogen, Cj-C4 lower alkyl, C1-C4 lower alkoxy, halogen, hydroxy, nitro or aminomethyl; Z is 0 or S? and m is 0 or 1; or R' is a group of the formula P-CHI io Q in which P is 2-thienyl, 3-thienyl, 1-tetrazolyl, or a phenyl group of the formula in which a and a' are as defined above; and 15 Q is hydroxy, formyloxy, acetoxy, carboxy, sulfo, amino, or -NHY in which Y is benzyloxycarbonyl, t-butyloxyearbonyl, R '0 It ,1 I » -C-NH-C-NH-, or -C-N-Ου x NH V in which R''' is hydrogen or C^-Cj alkyl, and V is phenyl, halophenyl, furyl, mono- or di-(C|-C3 alkyl)amino, or mono- or diphenylamino, or R’” and V. taken together with the group to which they are attached, form a heterocyclic group, R’’’ being - (CH2) - 3 in which n is 2 or 3, and V being -NR in which R is hydrogen, methanesulfonyl, C^-C^ alkyl; or I 9 9 II R is a group of the formula R -CH2- in which R is 2-thienyl; 3-thienyl; 2-furyl; 2-oxazolyl; 2-thiazolyl; 1-tetrazolyl; benzotriazolyl; l,3,4-thiadiazolyl-2-thio; 1,2,5-thiadiazolyl-2-thio; 1,3,4-oxadiazolyl-2-thio; pyridyl—thio; l-(4-cyano)-l,2,3-triazolyl; or 1-(3-cyano)1,2,4-triazolyl, provided that when R^ is lower alkyl, R2 is hydrogen or an alkali metal cation, and R 0 < 11 is the group R -C-, (i) R is not CH2—(C.^—C,_ alkyl), C2 or haloalkyl, cyanomethyl, C2 or C3 azidoalkyl, C2 or C3 hydroxyalkyl or benzyl optionally substituted by one or two C^-C^ lower alkyl, C^-C^ lower alkoxy, halogen or hydroxy groups, I (ii) when R is the group of formula P-CH- and P is a 2thienyl, 1-tetrazolyl or phenyl optionally substituted by one or two C^-C^ lower alkyl, C^-C^ lower alkoxy, halogen or hydroxy groups, Q is not hydroxy, carboxy, sulfo or amino, and ι ι r ι 9 (iii) when R is a group of formula R -CH2~, R is not 2-thienyl, 3-thienyl, 2-furyl, 2-oxazolyl, 2-thiazolyl, 1-tetrazoiyl or pyridylthio, and provided that when R^ is ethyl, R is other than hydrogen. The present invention also provides a process for preparing the cephalosporin compounds of formula I which comprises reacting a 3-acetoxymethylcephalosporin compound of formula II RNH τΐ J—n ch2-o-c-ch. 0' S ‘2 II wherein R and Rj are as defined above, with a mercaptotriazine derivative of the formula I wherein R^ is as defined above; optionally acylating the compound of formula I so obtained wherein R is hydrogen or Q is amino; I and if desired, removing the amino group A ( and the carboxy protecting group A or the amino protecting group Y, where Y is benzyloxycarbonyl or t-butyloxycarbonyl, and/or the carboxy protecting group R2, where R2 is a readily removable ester-forming group.

The invention further includes a pharmaceutical formulation comprising an antibiotically active compound of formula X as defined above associated with a pharmaaeutic15 ally acceptable carrier thereof . - 5 41580 Xn the above d'finition of R^, the term lower alkyl means an alkyl gioup having from 1 to 4 carbon' atoms, for example, methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, or isobutyl. Preferably, is methyl or ethyl, and, more preferably, is methyl.

Examples of the 3-substituent of the cephalosporin in which is as defined above include 5-oxo6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthiomethyl; 4methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio10 methyl; 4-cthyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-tr azin-3ylthiomethyl; 4-n-propyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4triazin-3-ylthiomethyl; 4-isopropyl-5-oxo-6-hydroxy-4,5-dihydro-1,2,4-triazin-3-ylthiomethyl; 4-n-butyl-5-oxo-6hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthiomethyl; 4-sec1 5 butyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-tfiazin-3-y1thiomethyl; and 4-isobutyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4triazin-3-ylthiomethyl.

R2 of formula I is hydrogen, ίΐη alkali metal cation, such as lithium, sodium, or potassium, or a readily removable ester forming group. The expression a readily re· movable ester forming group refers to the commonly employed carboxylic acid protecting groups used to block the carboxylic acid group of the cephalosporin molecule. Such groups are readily removable by conventional tech25 niques, and include, for example, C^-C^ tert-alkyl, C5~C6 tert-alkenyl, C5~C6 tert-alkynyl, benzyl, diphenylmethyl, p-nitrobenzyl, p-methoxybenzyl, 2,2,2-trichloroethyl, phenacyl, trimethylsilyl, C^-C^ alkanoyloxymethyl, and phthalidyl. fi Examples of C^-Cg tert-alkyl groups include, for ex.imple, t-butyl, t-amyl, and t-hexyl. Examples of C^-Cg toit-alkenyl groups are t-pentenyl and t-hexenyl. Examples of Cg-Cg tert-aikynyl groups are t-pentynyl and t-hexynyl.

When R2 is a readily removable ester forming group, it is preferred that it.be t-butyl, diphenylmethyl, aenzyl, p-iiitrobenzyl, jo-methoxybenzyl, 2,2,2-trichloroethyl, trimethylsilyl, acetoxymethyl, pivaloyloxymethyl, or phthalidyl. Most preferably, when R2 is a readily i >10 movable ester forming group, it is £-nitrobenzyl, ac< toxymethyl, or pivaloyloxymethyl.

Most preferably, however, R2 is hydrogen o an alkali metal cation. These R2 moities define those compounds of formula I which are most active antibio .ical15 !y· Cleavage of the ester moiety to the free 4 caiboxyi function is desireble to produce a cephalosporin in which is hydrogen or an alkali metal cation. cleavage is accomplished by conventional treatment. This inc udes, for example, treatment of the ester with an acid sucl as trifluoroacetic acid, or hydrochloric acid, or with : inc and an acid, such as formic acid, acetic acid, or hydrochloric acid. Cleavage likewise can be accomplished by hydrogenating the ester in the presence of palladium, rhodium, or a compound thereof, in suspension or on a carrier such as barium sulfate, carbon, or alumina.

In the foregoing definition of the group R', the term C^-Cg alkyl refers to straight and branched chain alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, sec-butyl, n-amyl, isoamyl, n-hexyl, - 7 41690 and 2,3-dimethylbutyl. The term C^-C^ haloalkyl refers to such groups as chloromethyl, bromomethyl, 2-iodoethyl, 2- chloropropyl, and 3-br xnopropyl. The term C^-C^ cyanoalkyl refers to such groups as cyanomethyl, 2-cyanoethyl, 3- cyanopropyl, and 2-eyauopropyl. The term C^-C^ azidoalkyl refers to such groups as azidomethyl, 2-azidoethyl, 3-azidopropyl, and 2-azidopropyl. The term C^-C^ hydroxyalkyl refers to such groups as hydroxymethyl, 2-hydroxyethyl, 3-hydroxypropyl, and 2-hydroxypropyl.

In defining the 4-substituted-amino-4-esterified carboxybutyl group, the term A’ includes the groups alkanoyl, C2-C4 haloalkanoyl, and halobenzoyl. The term C^-C^ alkanoyl” refers to acetyl, propionyl, or butyryl. The term C^-C^ haloalkanoyl refers to such groups as chloroacetyi, bromoacetyl, 2-chloropropionyl, or 3-hromobutyryl.

The term halobenzoyl refers to chloro and bromo-substituted benzoyl groups such as 4-chlorobenzoyl, 4-bromobenzoyl, and 2,4-dichlorobenzoyl.

As used herein, the term halogen and the term halo (except in the term halobenzoyl) each refers to fluoro, chloro, brcsno, or iodo. The term Cj-C^ lower alkyl refers to straight and branched chain alkyl groups such as methyl, ethyl, n-propyl, isopropyl, n-butyl, and t-butyl. The term °1~C4 lower alkoxy includes methoxy, ethoxy, isopropoxy, or n-butoxy.

The following are illustrative of the group O tt R'-C-NH- in Formula I above: formamido, acetamido, propionamido, butyramido, α-methylpropionamido, valeramido, α-methylbutyramido, trimethylacetamido, caproamido, heptano- 8 41590 amido, chloroacetamido, bromoacetamido, fluoroacetamido, iodoacetamido, 0-chloropropionamido, 3-bromopropionanido, β-ι-hlorobutyramido, γ-fluorobutyramido, cyanoacetamiio, acy inopropionamido, β-cyanopropionamido, /-eyanobutyrainido, .iz' doaccl amido, β-,ιζ.i.dopi opjonamido, /-azLdobutyramido, [1-.iz i dobutyrami do, hydroxyaeetamido, α-hydroxypropionamido, (3-nydroxybutyramido, ^-nitrobenzyloxycarbonylamino, 5-amino-5 carboxyvaloramido, 5-(diphenylmethoxyearbonyl)-5-(acetamido)valeramido, and 5-(p-nitrobenzyloxycarbonyl)-5-(2,4-di10 chlorobenzamido)valeramido.

The following are illustrative of the groups It R'-C-NH- in Formula X above in which R* is and in which m is 0: phenylacetamido, 4-methylphenylacet15 amido, i-etliylphenylacetamido, 4-isopropylphenylacetimido, 2-methylphenylacetamido, 4-chlorophenylacetamido, 4- ii trophenylacotamido, 4-bromophenylacetamido, 2,4-dichlor>phenylacetamido, 3-bromophenylacetamido, 4-fluorophenylacetamido, 2-fluorophenylacetamido, 3,4-dihydroxypheuyl20 acetamido, 4-hydroxyphenylacetamido, 3-hydroxyphenyllcetamido, 2,6-dimethoxyphenylacetamido, 3-methoxyphenylacetamido, 4-isopropoxyphenylacetamido, 3-ethoxyphen-'lacetamido, 4-methoxyphenylacetamido, 3,4-dimethoxyphenylacetamido, 4-t-butoxyphenylacetamido, 2-aminomethylpheny125 acetamido, 4-aminomethylphenylacetamido, J-n-butoxyp!ienylacetamido, 3-chloro-4-methylphenylacetamido, and 3-n..tro- 9 41530 phenylacetamido. When, in the above formula, m = 1 and 7, represents -0-, illustrative groups include the ft 1lowing: phenoxyacetamido, 4-methylphenoxyacetamido, 3- ethylphenoxyacetamido, 4-isopropylphenoxyacetamidf·, 2-methylphenoxyacetamido, 4-chlorophenoxyacetamido, 4- uitrophenoxyacetamido, 1-bromophenoxyacetamido, 2,4-dichlorophenoxyacetamido, 3-bromophenoxyacetamido, 4-fluorophenoxyacetamido, 2-fluorophenoxyacetamido, 3,4-dihydroxyphenoxyacetamido, 4-hydroxyphenoxyacetamido, 3-hy10 droxyphenoxyacetamido, 2,6-dimethoxyphenoxyacetamido, 3- ethoxyphenoxyacetamido, 4-methoxyphenoxyacetamido, 3,4-dimethoxyphenoxyacetamido, 4-t-butoxyphenoxyacetamido, 2-n-butoxyphenoxyacetamido, 3-chloro-4-methylphenoxyacetamido, 3-nitrophenoxyacetamido, 3-hydroxy-4-methylphenoxyacetamido, 2-chlorophenoxvacetamido, 3-hydroxy-4-methylphenoxyacetamido, 2-chlorophenoxyacetamido, 4-isopropoxyphenoxyacelamido, 2-ami nomethylphenoxyacetamido, and 4- iiminomethylphenoxyacetamido. When, in the foregoing formula, m = 1 and Z represents -S-, illustrative gioups in20 elude the following: phenylmercaptoacetamido, 4-mel hylphenylmercaptoacetamido, 3-ethylphenylmercaptoacetan ido, 4-isopropylphenylmercap toace tamido, 2-methylphenylme rcaptoacetamido, 4-chlorophenylmercaptoacetamido, 4-r,itrophenylmercaptoacetamido, 4-bromophenylmercaptoacetamido, 2,4-dichlorophenylmercaptoacetamido, 3-bromophenylmercaptoacetamido, 4-fluorophenylmercaptoacetamido, 2-fluorophenylmercaptoacetamido, 3,4-dihydroxyphenylmercaptoacetamido, 4-hydroxyphenylmercaptoacetamido, 3-hydroxyphenylmercaptoacetamido, 2,6-dimethoxyphenylmercaptoacetamido, 3-ethoxyphenylmercaptoacetamido, 4-methoxyphenylmercapto10 4159 .id tamido, 3,4-dimethylphonylmercaptoacetamido, 4-t.-butoxy pli.-ny I imu cupl.oaeetamirio, f-n-bu t.oxyphony 1 mcrcaptoacet,-ini do, {-chloro-4-mGtliyIphunyImercuptOcicetamido/ 3-nitroph 'nylmercaptoacetamido, 3, 4-dimethy Iphenylmercaptoacet5 am do, 3,4-dichlorophenylniercaptoacetamido, 2,5-dichlorophonylmorcaptoacetamido, 3 -fluoro-4-chlorophenylmercaptoiicotamido, 3-chloro-4-fluorophenylmercaptoacetamido, 2,6-difluorophenylmercaptoacetamido, 3-fluorophenylmercaptoacetamido, 2-aminomethylahenylmercaptoacetamido, and 4-aminomethylphenylmercaptoacetamido.

When R’ represents a group of the formula P-CH0 ό If illustrative groups having the overall formula R'-C-NH.ineludo the mandelaniido group of tho formula ii •CH-C-NHi OH the O-formyl and O-acetyl derivatives thereof represented by the general. formula II - - -CIl-C-NII77=7 ' 0a· · · 0.H r-r in which T is hydrogen or methyl; the a-carboxyphenylacetamido group represented by the formula I tool I /11590 the α-sulfophenylacetamido group represented by the formula X % >®-CH-C-NH1a SO H a the α-aininophenylacetamido group represented by the formula οζ y—CH-ONHa '^0=0' ' a NH or the a-(substituted-amino)phenylacetamido group represented by the formula I a NHY II CH-C-NHin which Y is benzyloxycarbonyl, t-butyloxycarbonyl, -C-NH-C-NHII Z NH or in which V is for example, phenyl, halophenyl, furyl, monomethylamino, dimethylamino, monoethylamino, diethylamino, methylethylamino, n-propylamino, di-n-propylamino, di-isopropylamino, phenylamino, or diphenylamino. Moreover, R’’ ’ can be hydrogen or C^-C^ alkyl, specifically methyl, ethyl, n15 propyl or isopropyl. R''' and V can, together with the group to which they are attached, form a heterocyclic group su· Ή that Y has the structure o II II -C-N-C-N-R (CHA i.u which n is 2 or 3 and R1’'' is hydrogen, methanesulfonyl, or alkyl. Also included are those a-substituted 2-thienylacetamido, 3-thienylacetamido, and 1-tetrazolylacetamido groups in which, in the above formulae, the phenyl group is replaced by a 2-thienyl, a 3-thienyl, or a 1-tctrazolyl group.

Illustrative of the foregoing acetamido groups 10 are 4-methylmandelamido, 4-hydroxymandelamido, 3-hydroxymandelamido, 4-methoxymandelamido, 3-bromomandelamido, mandelamido, 4-chloromandelamido, 3-methyl-4-fluoromandclamido, 2-fluoromandeiamido, 4-fluoromandeiamido, 4-isopropylmandelaniido, s,4-dimethyl-O-formylmandelamido, 4-chloro-O-formylmandelamido, 3-isopropoxy-0-formylmandelamido, 3-bromo-0-formylmandelamido, O-formylmandelamido, 3,4-dimethoxy-0-formylmandelamido, O-acetylmandelamido, 4-hydroxy-0-acetylmandelamido, a-hydroxy-2-thienylacetamido, α-hydroxy-3-thienylacetamido, a-formyloxy-2-thienylacetamido a-acetoxy-2-thienylacetamido, a-formyloxy-3-thienylacetamido, a-acetoxy-3-thienylacetamido, a-hydroxy-l-tetrazolylacetamido, a-formyloxy-l-tetrazolylacetamxdo, a-acetoxy1-tetrazolylacetamido, «-carboxyphenylacetamido, a-carboxy-4methylphenylacetamido, a-carboxy-4-hydroxyphenylacetamido, a-carboxy-3-hydroxyphenylacetamido, a-carboxy-4-methoxyphenylacetamido, a-carboxy-3-bromophenylacetamido, a-car- 13 boxy-4-chlorophenylacetamido, α-carboxy-3-methyl-4fluorophenylacetamido, a-carboxy-2-fluorophenylacetamido, a-carboxy-4-fluorophenylacetamido, a-carboxy-4-isopropylphenylacetamido, a-carboxy-3,4-dimethylphenylacetamido, a-carboxy-3-isopropoxyphenylacetamido, a-carboxy-3,4dimethoxyphenylacetamido, α-carboxy-2-thienylacetamido, a-carboxy-3-thienylacetamido, a-carboxy-l-tetrazolylacetamido, α-sulfophenylacetamido, a-sulfo-4-methylphenylacetamido, a-sulfo-4-hydroxypheny1acetamido, a-sulfo-3-hydroxyphenyl10 acetamido, a-sulfo-4-methoxyphenylacetamido, a-sulfo-3bromophenylacetamido, a-sulfo-4-ehlorophenylacetamida, a-sulfo-3-methyl-4-fluorophenylacetamido, a-sulfo-2-fluorophenylacetamido, a-sulfo-4-fluorophenylacetamido, a-sulfo-4-isopropylphenylacetamido, a-sulfo-3,4-dimethyl15 phenylacetamido, a-sulfo-3-isopropoxyphenylacetamido, a-sulfo-3,4-dimethoxyphenylacetamido, a-sulfo-2-thienylacetamido, a-sulfo-3-thienylacetamido, a-sulfo-l-tetrazolylacetamido, a -aminophenylacetamido, a-amino-4-methylphenylacetamido, a-amino-4-hydroxyphenylacetamido, a-amino20 3-hydroxyphenylacetamido, a-amino-4-methoxyphenylacetamido, a-amino-3-bromophenylacetamido, α-amino-4-chloropheny1acetamido, a-amino-3-chloro-4-hydroxyphenylacetamido, a-amino-2-fluorophenylacetamido, α-amino-4-fluorophenylacetamido, a-amino-4-isopropylphenylacetamido, a-amino25 3,4-dimethylphenylacetamido, a-amino-3-isoprophenylacetamido, a-amino-3,4-dimethylphenylacetamido, a-amino-2thienylacetamido, a-amino-3-thienylacetamido, a-amino-1tetrazolylacetamido, a -(3-guanyl-l-ureido)-phenylacetamido, a-(3-methylaminocarbonyl-l-ureido)phenylacetamido, α-(i-dimethylaminocarbonyl-3-methyl-l-ureido)phenylacetamido, α-[N-(imidazolidin -2-οη-ί-ylcarbonyl)aminoi phenylacetamido, α- [N- (3-methylimidazolidin-2-on-l-ylcarbonyl)amino]phenylacetamido; α-[N-(3-methanesulfonylimidazalidin 2-on-l-ylcarbonyl)amino| phenylacetamido; α-JN- (hexahydropyrimidin-2-on-l-ylcarbonyl)amin0[ phenylacetamido; α-[N-(3-methylhexahydropyrimidinT-2-on-i~ylcarbonyl)amino]phenylacetamido; a-[N-(3-methanesulfonylhexahydropyrimidin-2~on-l-ylcarbonyl)amiiiol phenylacetamido; a-(3-phenylaminocarbonyl-3-propyl-l-ureido)phenylacetamido, and a-(3-di-n-propylaminocarbonyl-l-ureido)phenylacetamido . tl The groups R’ -C-NH- in Formula 1 in which R’ is R” -CHg- are the following: 2-thienylacetamido, 5-thienylacetamido, 2-furylacetamido, oxazolyl-2-acetamido, thiazolyl-2-acetamido, tetrazol/1-i-acet amido, benzotriazolylacetamido, l,3,4-thiadiazolyl-2thioacetamido, 1,2,5-thiadiazolyl-3-thioacetamido, 1,3,4-oxadiazolyl-2-thioacetamido, pyridylthioacetamido, 4-(cyano)-1,2,3-triazolyl-l-acetamido, and 3-(cyano)-1,2,4triazolyl-l-acetamido.

A preferred group of cephalosporins of formula I is represented by the following formula III . 44590 OH 11 1 / \ (Z) -CH -C-N-i---A, V .OH III COOR in which R^, R2, a;, a', Z and m have the same meanings as defined above. Illustrative of these preferred compounds presented in the form of their free acid are the following: 7-phenoxyacetamido-3-(4 - ethyl-5-oxo-6-hydroxy-4,5- 7-(4-hydroxyphenylacetamido)-3-(5-oxo-6-hydroxy-4,5-dihydro1,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid, 7-(4-chlorophenoxyacetamido)-3-(4-n-propyl-5-oxo-6-hydroxy10 4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid, 7-(4-methoxyphenoxyacetamido)-3-(4-methyl5-oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl3-cephem-4-carboxylic acid, 7-(2,5-dichlorophenylthioacetamido)-3-(4-isopropyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-tria15 zin-3-ylthio)methyl-3-cephem-4-carboxylic acid, and 7-phenylthioacetamido-3-(4-n-butyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid.

Another preferred group of cephalosporins of formula I is that represented by the following formula IV - 16 41590 Ο II (IV) wherein 1’ represents 1-tetrazolyl, phenyl, or a substituted, phenyl group as defined herein and Q is hydroxy, formyloxy, acetoxy, carboxy, or amino, and R^ and R^ are as defined before Illustrative of the foregoing compounds represented by formula IV and presented as their free acid are the following: 7-(4-d, l.oromandel ami do )-3-(5-»xt>-6-liydroxy-4,5“ dihydro-1,2,4-triazin-3-ylthio)methyl-3-cephem-4-cai boxylic acid. 7-(a-formyloxyphonylacctamido)-3-(4-ethyl-5-ox<>6-hydroxy-4,5-dihydro-l,2,4-triazin-3-yithio)tnethyl-3cephem-4-carboxylic acid. 7-(a -acetoxyphenylacetamido)-3-(4-isobutyl-5-oxo6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3<:eplieni-4-carboxyl ie aci d. 41 590 Another preferred group of cephalosporins of formula I in that represented by the following formula V wherein is H or a lower alkyl other than ethyl and is as defined before.

These structures are highly useful as intermediates in preparing other compounds of this invention. They are readily convertible to other compounds by routine acylation procedures by which the free amino substituent in the 710 position is acylated with any of the herein defined acyl substituents. Illustrative of these compounds represented by formula V and presented as their free acid are the following: 7-amino-3-(5-oxo-6-hydroxy-4,5-dihydro-l,2,415 triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid, 7-amino-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro1.2.4- triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid, 7-amino-3-(4-n-propyl-5-oxo-6-hydroxy-4,5-dihydro1.2.4- triazin-3-ylthio)methyl-3-cephem~4-carboxylic acid, 7-amino-3-(4-isopropyl-5-oxo-6-hydroxy-4,5-dihydro1.2.4- triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid, 7-amino-3-(4-n-butyl-5-oxo-6-hydroxy-4,5-dihydro-l, 2, 4-triazin-3-ylthio) methyl- 3-cephem-4-carboxy lie acid, - 18 41590 7-amino-3-(4-sec-butyl-5-oxo-6-hydroxy-4,5dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid, and 7-amino-3-(4-isobutyl-5-oxo-6-hydroxy-4,55 dihydro-1,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid.

The compounds of formula I can be prepared by well recognized cephalosporin preparative techniques. They are readily available by displacement of an acetoxy function present in the 3-position of a 3-acetoxymethyl cephalosporin compound. Thus, any of the cephalosporins of formula I can be prepared from the corresponding 3-acetoxymethyl cephalosporins by the well recognized displacement reaction. Thus, a typical sequence for preparing any of the compounds of formula I from readily available 7-aminocephalosporanic acid (7-ACA) can be as follows: Η Ν— 2 .A Π L, Λα ο II O-C-CH COOH d1spIacement I COOH R protection of C carboxyl 4 (If desired) acylation (I f des I red) In accordance with the above scheme, the acetoxy function of 7-ACA is displaced with the defined triazinylthio derivative. The resulting product is the corresponding 7-amino cephalosporin, a compound of formula I. This compound can be converted by means of well recognized acylation techniques to any of the defined 7-acylamido cephalosporins of formula I.

The above sequence can be altered such that the 7-ACA is first acylated in the 7-position to produce the corresponding 7-acylamidocephalosporanic acid or ester thereof. The resulting product, if an ester, is then optionally cleaved to remove the ester protecting group, and the resulting acid is then subjected to the displacement reaction to produce the compound of formula I. All. of these procedures used to accomplish these conversions are well recognized in the art.

The particular compound which is employed to displace the acetoxy function in the 3-position is a 3-mercapto-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-triazine unsubstituted in the 4-position or suitably substituted in the 4-position with a lower alkyl group as herein defined. These 3-mercapto-l,2,4-triazines are prepared by a method described in Pesson et al., Bulletin de la Soclete Chimique de France, (1970), pages 1590-1599. In accordance with the method described in this publication, the 1,2,4-tria15 zine is obtained by reaction of a thiosemicarbazide with diethyl oxalate in the presence of sodium ethoxide.

H I I I R1 R, In this triazine derivative R^ is hydrogen or lower alkyl as herein defined. As noted, the product existe in tauto20 meric forms. The tautomer aspect is detailed in Pesson - 21 41590 et al., Bulletin de la Societe Chimique de France. (1970), pages 1599-1606.

The aforementioned displacement reaction employed in preparing compounds of formula I comprises reacting the corresponding 3-acetoxymethyl compound preferably in a polar medium with the appropriate 3-mercapto-l,2,4-triazine derivative so as to displace the acetoxy group. The desired 3-substituted cephalosporin derivative is then recovered.

This reaction may conveniently be effected by 10 maintaining the reactants in solution at a temperature such as, for example, from about 15°C. to about 100°C. and until the desired derivative is obtained in optimum yield. The reactants are advantageously employed in a ratio of about 1 molar equivalent of the 3-acetoxymethyl cephalosporin to from about one to about ten molar equivalents of the 3-mercapto-l,2,4-triazine. Preferably, the reaction is carried out using equimolar amounts of these reactants or a moderate excess of the triazine compound.

The pH of the reaction solution is advantageously maintained at from about 5.0 to about 8.0.

The reaction appears to proceed by a polar or ionic mechanism. It is preferred therefore to employ a polar medium for the reaction. This facilitates the ready advance of the desired reaction. Water may be employed as the polar medium and, indeed, is preferred. Any other typical and well recognized polar solvents can be employed as well. It is also possible to employ as supporting medium for the reaction an excess of the displacing 3mercapto-1,2,4-triazine derivative. - 22 41590 The resulting reaction product can be separated from the reaction mixture by a variety of methods including crystallization, ionophoresis, paper chromatography, and chromatography on ion-exchange resins.

The displacement reaction can be applied either to 7-amino- or to a 7-acylamido cephalosporanic acid. When 7-ACA is employed, the resulting product can then be acylated.

The acylation of the 7-amino group of cephalosporins is a well-known reaction and can be accomplished by reacting the cephalosporin with an acid halide or mixed anhydride representative of the desired acyl function. The particular method of acylation is not important to this invention.

The compounds of formula I are themselves antibiotically active and/or are intermediates in the preparation if antibiotically active compounds. Those compounds which particularly exhibit antibiotic activity are those in which R2 is hydrogen or an alkali metal cation. Compounds in which R2 is other than hydrogen or an alkali metal cation are readily converted thereto by cleavage techniques hereinbefore described.

In the Table following, the minimum inhibitory concentrations (MIC) in micrograms per milliliter (meg/ml) of compounds of formula I againet a gram-negative organism, Escherichia coli, and against a gram-positive organism, penicillin-resistant Staphylococcus aureus, are provided.

The MIC values were determined by the Gradient Plate technique described in Bryson and Szybalski, Science, 116, (1952).

Table Antibiotic Activity R —l— Minimum Inhibitory Cone, (mcg/ml) E. Coli S. aureus C1H.H- ch3 50 15 H-CO- ch3 12.2 0.2 2,5-dichlorophenylthioacetyl ch3 20.5 0.6 2,5-dichloro- phenylthio- acetylC2H5 22.5 0.7 a-formyloxyphenyl- acetyl a-(t-butyloxycarbonylamino)phenylacetyl ch3 ch3 3.5 130 4.0 0.5 20 4-aminomethyl- phenylacetyl ch3 3.0 0.5 a-[3-(4-chlorobenzoyl)-3methyl-l-ureido]phenylacetyl ch3 4.5 4.0 - 24 10 Table Antibiotic Activity cont'd. a- (3-furoyl-lureido)phenylacetyl a- [3- (2-chlorobenzoyl)-3methyl-1ureido]phenylacetyl Minimum Inhibitory Cone, (mcg/ml) Ε· Coli S. aureus CH3 8.3 7.0 CH3 5.7 5.5 a-(3-methylaminocarbonyl-3methy1-1-ureido)phenylacetyl CH3 a-(imidazolidin2-on>-l-yl-carbonylamino)phenylacetyl CH3 a-(3-methanesulfonylimidazolidin-2-on-lylcarbonylamino,phenylacetyl ch3 .5 3.0 19.0 2.0 9.5 5.0 a-(3-methyl-3methylaminocarbonyl-1ureido)thien-2ylacetyl CH3 14.2 1.0 . 41590 Table Antibiotic Activity cont'd.

Minimum Inhibitory Cone, (mcg/ml) R a-(3-methanesulfonylimidazolidin-2-on-lylcarbonylamino)thien-2-yl- -i- E. Coli S. aureus 5 acetyl a- [3-(2-chlorobenzoyl)-3-methyll-ureido]-4hydroxyphenyl- CH3 4.7 1.0 10 acetyl a-(3-methanesulfonylimidazolid.in-2-on-l-ylcarbonylamino)4-hydroxypheny1- ch3 11.1 0.7 15 acetyl a-(3-methylaminocarbonyl-3-methy11-ureido)-4hydroxyphenyl- ch3 0.6 . 2.5 20 acetyl a-(imidazolidin 2-on-l-ylcarbonylamino)-4.hydroxyphenyl-CH3 4.4 2.2 25 acetyl ch3 5.6 2.1 The preparation of the compounds of this invention is illustrated by the following Examples 1,3 to 9, 11 to 14 and 16 to 21. Examples 2,10 and 15 relate to the preparation of intermediates.

Preparation of 3-Mercapto~4-methyl~5-oxo6-hydroxy-4,5-dihydro-l,2,4-triazine To a 22 liter (1.) flask containing 12.5 1. of anhydrous ethanol,maintained in a nitrogen atmosphere were slowly added 230 g. of sodium. The mixture was maintained at room temperature overnight, a slow, but constant, stream of nitrogen being admitted to the flask.

The mixture then was heated to 50°C., and 1050 g. (10 mole) of 4-methylthiosemicarbazide were added. The temperature of the mixture fell to 40°C. To the mixture were then added 1530 g. of diethyl oxalate through a funnel. Addition was at a rate sufficient for the reaction mixture to attain a temperature of from about 60°C. to about 65°C. The temperature of the resulting mixture rose to 65°C. The mixture was refluxed with stirring for four hours, during which time a precipitate formed. The precipitate changed in appearance during the period of reflux. Upon discontinuing heating and stirring, the white solid gradually settled to the bottom of the flask, leaving a clear light-yellow supernatant liquid. The mixture was allowed to stand overnight. The bulk of the clear supernatant was removed by suction, and the white crystalline product in the form of its sodium salt was removed from the residual mixture by filtration and washed with dry ethanol.

The product was dissolved in water, and the pH of the solution was adjusted to pH 5.5. A small amount of material was filtered off and discarded. The pH of the - 27 41590 filtrate then was adjusted to 1.5, cooled, and filtered to obtain 211.5 g. of the desired product, m.p. 212-216°C.

Example 1 To 36 ml. of water were added with stirring 1.44 g. of 3-mercapto-4-methyl-5-oxo-6-hydroxy-4,5dihydro-l,2,4-triazine and 8.5 ml. of 1 N sodium hydroxide.

The pH of the resulting mixture was 8.3, and the pH was lowered to 7.6.by addition of dilute acid. 7-a-(t-Butoxycarbonylamino)phenylacetamido-3-acetoxymethy1-3-cephem-4oarboxylic acid (4.5 g., 9 mmole.) was added to the mixture with stirring, and the pH of the resulting mixture adjusted to 6.9 as the cephem compound slowly went into solution.

The mixture was stirred at 55°C. After 1.75 hours, the pH of the mixture was 6.2, and the pH was adjusted upward to 7.3 by addition of dilute sodium hydroxide. After 17.5 hours, the pH of the mixture was 6.1 and was adjusted to 6.95 by addition of dilute sodium hydroxide. The mixture was heated a total of 21 hours. The mixture was cooled in ice, filtered, and the filtrate was adjusted to pH 1.5.

A solid precipitated. The solid was filtered off, washed with dilute acid (pH 1.5), and air dried to give a light buff colored powder (3.60 g.). The powder was dissolved in 15 ml. of a 2:1 mixture of water and methanol at pH 6.5. The mixture was rotary evaporated to a small volume (about 3 ml.) with isopropyl alcohol being added to avoid frothing toward the end of the rotary evaporation. The residual solution was placed on a Sephadex G-10 (54 g.) column (the word Sephadex)1 is a Trade Mark) and eluted with water, the first fraction being 25 ml. and all succeeding fractions about 15 ml.' Fractions 5-8 were combined, and the pH of the mixture was adjusted to 1.5 by addition of dilute - 28 41S90 hydrochloric acid. The precipitated product was collected by filtration, washed with dilute acid (pH 1.5), and air dried to give 2.19 g. of 7-a-(t-butoxycarbonylamino)pheny1acetamido-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4triazin-3-ylthio)methyl-3-cephem~4-carboxylic acid as a buff powder.

NMR DMSO dg: 9.18 (d, 1H, 73-NH) ; 7.3 (bm, 5H, (¾) ; 5.71 (q, 1H, 7a-H); 4.05 (m, 2H, 3-CH2); 3.55 (m, 2H, 2-CH2); 3.27 (s, 3H, triazine N-CH3); and 1.36 ppm (b, 9H, t-C4H9).

Example 2 The product from Example 1 (404 mg.) was stirred in 4.5 ml. of acetonitrile; however, complete dissolution was not achieved. p-Toluenesulfonic acid (300 mg.) was added, and within 5 minutes dissolution was complete, and a solid began to separate. After 1.5 hours, water (0.5 ml.) was added, and the pH of the mixture was adjusted to 5.0 by addition of saturated aqueous ammonium carbonate solution.

A major portion of the acetonitrile was removed by rotary evaporation, and isopropyl alcohol was added to the stirred residue until some precipitation became evident. The precipitate was removed by filtration through a filter aid. Some tendency to further precipitation was noted upon passage of the solution through the filter aid. The filtrate was stirred and diluted with isopropyl alcohol to give a further precipitate which was collected by filtration, washed with a mixture of isopropyl alcohol and water, and air dried to give a buff colored powder (0.18 g.). This powder was mixed with similar material from a larger scale reaction, the combined material weighing 1.23 g. This material was stirred in the cold in a mixture of 30 mL. of water and 30 ml.' of methanol. The pH of the mixture was slowly adjusted to· 7.0 by addition of IN aqueous sodium hydroxide. Λ small amount of insoluble material was removed by filtration, The filtrate was concentrated to about 5 ml· by rotary evaporation, isopropyl alcohol being used in the later stages to prevent frothing. The residual solution was placed on a column of Sephadex G-10 (28 g., 1.5 cm.) in water, and 25 ml. fractions were collected, water being used as eluant. Fractions 3~9 were combined. The pH of the combined fractions was adjusted to pH 3.5, and the precipitated product was collected by filtration. The solid was washed with water which had been acidified to pH 3*6 by addition of HCl, and air-dried to give 620 mg. of 7-( ct-amino) phenylacetarnido-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin3-ylthio)methyl-3-cephem-4-carboxylic acid as a light brown powder.

NMR, TFA dj! 7.58 (b, 5H, C^); 5-96 (d, 1H, 7a-H)j 5.57 (s, 1H, C6H5-CH)j 5.21 (d, 111, 6a-H)j 4-43 (g, 211, 3-CH2)j 3.77 (b, 2H, 2-ClI2): and 3.58 ppm (s, 3H, triazine N-CH^).

Example 3 To 20 ml. pf water were added 3-46 g. of 7-formamido3-acetoxymethyl-3-cephem-4-carboxylic acid (12.0 mmole) and 2.0 g. of 3-mercapto-4-methyl-5-oxo-6-hydroxy-4,5dihydro-l,2,4-triazine (12.55 mmole). The resulting mixture was stirred, and IN sodium hydroxide was added gradually until the pH remained at a constant 7.0 The resulting mixture was then stirred at about 55°C. for 26 hours.

The resulting solution was concentrated to 20 ml. and acidified to pH 1.2 by addition with cooling of 3N hydrochloric acid. The resulting precipitate was filtered off - 30 41590 and immediately placed in a bell jar to dry under vacuum. The dried material was ground with a mortar and pestle (2.75 g.), and was triturated three times, each with 150 ml. of boiling isopropyl alcohol. The isopropyl alcohol solution •5 was evaporated to dryness and the residue was triturated twice with 30 ml. of ethyl acetate. The insoluble material was filtered off',washed with ethyl acotato, and dried to give 1.56 g. of 6-formamido-3-(4-methyl-5-oxo-6-hydroxy-4,5dihydro-1,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid.

NMR, DMSO d6-D2O: 8.24 (s, 1H, OC-H); 5.79 (d, 1H , 7a-H); 5.14 (d, 1H, 6a-H); 3.73 (b, 2H , 2-CH2) and 3 .40 ppm (s, 3H, triazine N· -ch3).

Example 4 The product from Example 3 (0.74 g.) was stirred in 12 ml. of dry methanol, and 1.5 ml. of concentrated hydrochloric acid were added ,during which time complete dissolution occurred. After a short period of time, a white solid began to precipitate. Stirring was continued for 1.7 hours, and the mixture became thick with a white precipitate. The precipitate was filtered and dried. The product (0.346 g.) was shown by TLC to be a highly pure sample of the hydrochloride salt of 7-amino-3-(4-methyl-5oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-325 cephem-4-carboxylic acid.

NMR, DMSO dg: 5.19 (q, 2H, 7a-H and 6a-H); 4.19 (m, 2H, 3-CH2); 3.77 (b, 2H, 2-CH2); and 3.31 ppm (s, 3H, triazine N-CH3).

Example 5 To 12 ml. of water were added with stirring 531 mg· (3 mmol.) of 3-mercapto-4-methyl-5-oxo-6-hydroxy-4,5dihydro-l,2,4-triazine. The pH of the resulting mixture was 2.3 and was adjusted to 6.5 by addition of 2.9 ml. of IN sodium hydroxide. 7-(2,5-Dichlorophenylthio) acetamido -3-acetoxymethyl-3-cephem-4-carboxylic acid (1.54 g·, 3 mmol.) was added with stirring and resultant formation of a gelatinous mass. The mixture was heated to 60°C. Dissolution occurred, and,while maintaining the mixture at this temperature, the pH was adjusted to 7.0 and the mixture was maintained thereat for 19 hours. After the first l6 hours, the mixture was thick and gelatinous, so much so that stirring stopped. The mixture was thoroughly mixed with a spatula, and heating without stirring was continued for the remaining three hours.

On completion of heating, the mixture was cooled in an ice bath and acidified to pH 1.5. Fluidity of the mixture was maintained by dilution to about 100 ml. by addition of water. After stirring at pH 1.5 at room temperature for 1.5 hours, the mixture was filtered and the precipitate washed, with dilute HCl (pH 1.5), and air-dried to give a cream-colored powder.

The powder was dissolved in tetrahydrofuran (THF), filtered, and diluted with ethanol. The resulting solution wan placed in an air stream, by means of which solid was deposited, followed by a yellow gum. The gum was removed with a spatula. The resulting concentrate was filtered, and the precipitate was washed with ethanol and air-dried to give an off-white solid (861 mg.). The recrystallization procedure was repeated to give 707 mg. of 7-(2,5-dichlorophenylthio) acetamido-3(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio) methyl-3-cephem-4-carboxylic acid as an off-white powder.

NMR, DMSO dg-D2O: 7.4 (bm, 4H, 2,5-dichlorophenyl); 5.70 (d, IH, 7a-H); 5.11 (d, IH, 6a-H); 4.15 (b, 211, 2-CH2) i 3.92 (b, 2H, 7-CII.j) ; 3.69 (b, 211, 2-CII2) ; and 3.33 (b, 311, triazine N-αψ .

Example 6 To 12 ml. of water were added with stirring 571 mg. of 3-mercapto-4-ethyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4triazine. The pH of the resulting mixture was 2.3 and was adjusted to 6.6 by addition of 2.9 ml. of IN sodium hydroxide. 7-(2,5-Dichlorophenylthio)acetamido-3-acetoxymethy1-3eephem-4-carboxylic acid, sodium salt (1.54 g., 3 mmol.) was added, and the resulting mixture was treated in accordance with the procedure described in Example 5 to obtain 7-(2,5dichlorophenylthio)acetamido-3-(4-ethyl-5-oxo-6-hydroxy4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid.

NMR, DMSO dg-D2O: 7.4 (bm, 4H, 2,5-dichlorophenyl); 5.68 (d, IH, 7a-H), 5.10 (d, lH, δα-H); and 4.5-3.5 ppm (bm, 8H, 7-CH2, 2-CH2, 3-CH2, and CH3-CH2).

Example 7 To 12 ml. of dry THF were added 350 mg. (0.695 mmol.) of 7-(α-amino)phenylacetamido-3-(4-methyl-5-oxo-6hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem4-carboxylic acid^followed by 917 mg. (7 mmol.) of N-trimethylsilylacetamide. Upon completion of dissolution, ml. of propylene oxide was added^followed by 75 mg. (0.75 mmol.) of N-(p-chlorobenzoyl)-N-(chloroformyl,methylamine dissolved in 2 ml. of dry THF. The addition was made while the mixture was maintained at a temperature of -10°C. The resulting mixture was stirred at -10°C. for 10 minutes and then at room temperature for 15 minutes.

Water (1 ml.) was then added followed by 30 ml. of aqueous sodium bicarbonate solution. The mixture then was washed tilth 50 ml. of a 6:1 mixture of ethyl acetate and THF. The pH of the aqueous layer was lowered to 2.0 by addition of IN HCl in the presence of 50 ml. of a 6:1 mixture of fresh ethyl acetate and THF. The organic layer was separated and dried over magnesium sulfate. The mixture then was filtered and evaporated to dryness. The powder residue then was dissolved in warm ethyl acetate, and the ethyl acetate solution was concentrated until it became cloudy. Isopropyl alcohol then was added, complete dissolution being achieved, and the mixture was again concentrated until the solution became cloudy. The concentrated solution was refrigerated overnight to obtain 234 mg. of 7-a-[3-(4-chlorobenzoyl)-3methyl-l-ureido]phenylacetamido-3-(4-methyl-5-oxo-6hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem- 4-carboxylic acid. NMR, DMSO d6-D2O: 7.60 and 7.45 i (two b, 9H, aromatic); 5.77 (d, 1H, 7a-H); 5.63 (s, 1H, 7-CH); 5.05 (d, 1H, 6a-H); 3.66 (m, 2H, 2-CH2); 3.40 (s, 3H, triazine N-C H3); and 3.17 ppm (s, 3H, CON(CH3)CO).

Example 8 To 10 ml. of dry THF were added 379 mg. (0.75 mmol.) of 7-(α-amino)phenylacetamido-3-(4-methyl-5-oxo-6hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem4-carboxylio acid and 586 mg. (4.5 mmol.) of N-trimethyl- 34 41590 silylacetamide. The mixture was stirred at room temperature for 2 hours. Upon completion of solution, 1 ml. of propylene oxide was added, and the solution was cooled to 0°C. N-(o-Chlorobenzoyl)-N-(chloroformyl)methylamine (239 mg., 1.03 mmol.) dissolved in 5 ml, of dry THF was then added dropwise, and the reaction mixture was stirred for 30 minutes at 0°C. and for one hour at room temperature. Five ml. of water were then added, and the THF was removed in vacuo To the residue then were added 50 ml. of an aqueous sodium bicarbonate solution. The resulting mixture was washed with ethyl acetate, and the pH of the aqueous layer was lowered to 2.0 by addition of IN HCl. The acidified aqueous mixture then was extracted with 100 ml. of a 6:1 mixture of ethyl acetate and THF. The organic layer was separated, dried over magnesium sulfate, and filtered, and the filtrate was evaporated to dryness. The resulting foam residue was dissolved in ethyl acetate, and ether was added to precipitate 140 mg. of 7-a-(3-(2-chlorobenzoyl)-3-methyl1-ureido]phenylacetamido-3-(4-methyl-5-oxo-6-hydroxy-4,5dihydro-1,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid, which was collected by filtration.

NMR, DMSO dg-D2O: 7.54 and 7.41 (two b, 9H, aromatic); 5.73 (d, III, 7a-H); 5.59 (s, 1H, 7-CH); 4.07 (m, 2H, 3-CH2); 3.58 (m, 2H, 2-CH2); 3.28 (s, 3H, triazine N-CH^); and 2.94 ppm (s, 3H, CON(CH3)CO).

Example 9 To 20 ml. of dry THF were added 350 mg. (0.695 mmol.) of 7-(α-amino)phenylacetamido-3-(4-methyl-5-oxo-6hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem3 5 4-carboxylic acid followed by 786 mg. (6 mmol.) of Ntrimethylsilylacetamide. The resulting mixture was stirred at room temperature for 2 hours during which time dissolution resulted. Furoyl-2-isocyanate (97.5 mg., 0.71 mmol.) was then added, and the reaction mixture was stirred for 1 hour at room temperature. Water (20 ml.) then was added to the solution. The mixture was reduced in volume until a cloudiness developed at which time 40 ml. of aqueous sodium bicarbonate solution were added. The solution became clear and was washed twice with 50 ml. of ethyl acetate. The aqueous layer was separated, and the pH was lowered to 2.0 by addition of IN HCI. The layer was then extracted twice with 50 ml. of ethyl acetate. The ethyl acetate extracts were combined, dried over magnesium sulfate, filtered and evaporated to a foam residue. The residue was dissolved in warm ethanol, and the ethanol solution was concentrated until a cloudiness developed. The thusconcentrated ethanol solution was then refrigerated to obtain, upon filtration, 152 mg. of 7-a-(3-furoyl-l-ureido)20 phenylacetamido-3-(4-methy1-5-oxo-6-hydroxy-4,5-dihydrol,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylio acid.

NMR, DMSO dg: 8.03; 7.7X and 6.73 (each IH, furoyl); 7.46 (b, 5H, phenyl); 5.78 (bm, 2H, 7a-H and 7-CH); 5.07 (d, IH, 6a-H); 4.14 (b, 2H, 3-CH2); 3.61 (b, 2H, 2-CH2); and 3.32 ppm (s, 3H, triazine N-CHj).

Example 10 To 50 ml. of dry tetrahydrofuran (THF) were added 1.85 g. (5 mmole) of 7-amino-3-(4-methyl-5-oxo-6-hydroxy30 4,5“dihydro-l,2,4-'fcriazin-3-ylthio)methyl-3-cephem-4carboxylic acid and 3.6 ml. (15 mmole) of Ν,Ο-bis-trLmethylsilylacetamide. The mixture was stirred until - 3.6 41580 solution was complete. The solution then was cooled to -20°C.

Separately, 1.97 g. (5.5 mmole) of the sodium salt of N-(2-methoxycarbonyl-l-methylethenyl)-4-trimethylsilyloxyphenylglycine were added to a solution of 0.085 g. (0.5 mmole) of N-trimethylsilylsuccinimide in 75 ml. of dry tetrahydrofuran. To the resulting mixture were added 6 drops of Ν,Ν-dimethylbenzylamine. The resulting suspension then was cooled to -15°C., and 0.52 g. (5.5 mmole) of methyl chloroformate was added with stirring. The mixture was stirred for 15 minutes at -15°C., and the above solution containing the cephalosporin starting material was added. The resulting reaction mixture was stirred for two hours at -20°C. and then for one hour at room temperature.

High pressure liquid chromatography of the reaction mixture indicated the presence of approximately 60 percent of reaction product and 40 percent of the cephalosporin starting material.

The reaction mixture was worked up by adding 10 ml. of methanol to the mixture. A precipitate formed and was removed by filtration. To the filtrate then were added 10 ml. of water. The mixture was stirred for 15 minutes, and the resulting precipitate was filtered off. The filtrate was evaporated in vacuo to about 40 ml., and the concentrated mixture then was cooled overnight ip a freezer.

A precipitate formed which was collected by filtration.

The resulting collected solid was stirred in 15 ml. of water. The pH of the mixture was adjusted to 1.1 by addition of 3 drops of concentrated hydrochloric acid. The acidic mixture then was stirred for five minutes, and the 415 9 0 insoluble matter was filtered off. The pH of the filtrate was raised to 3.0 by addition of sodium hydroxide, and the resulting mixture was stirred for 10 minutes at ice bath temperature.

A precipitate formed and was collected by filtration. To the resulting filtrate was added 1 volume of isopropyl alcohol, and the mixture was evaporated in vacuo to about 10 ml. The concentrated solution was stirred in an ice bath for 15 minutes, and the resulting precipitate, 73 mg. of 7-(a-amino-4-hydroxyphenyl)acetamido-3-(4-methyl-5-oxo6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3cephem-4-carboxylic acid, was collected by filtration.

NMR, TFA d^: 7.29 (q, 4H, p-hydroxyphenyl); 5.86 (d, 1H, 7a-H); 5.52 (s, 1H, 7-CH); 4.48 (q, 2H, 3-CH2), and 3.8-3.54 ppm (b, 5H, triazine N-CH3 and 2-CH2).

Example ιl To 25 ml. of dry THF were added 252 mg. (0.5 mmole) of 7-(α-amino)phenylacetamido-3-(4-methyl-5-oxo6-hydroxy-4,5-dihydro-1,2,4-triazin-3-yIthio)methyl-3cephem-4-carboxylic acid and 650 mg (5 mmole) of N-trimethylsilylacetamide. The mixture was stirred for about 3 hours after which time solution occurred. The solution then was cooled to 0°C., and 76 mg. (0.5 mmole) of Ν,Ν'-dimethyl-N-(chloroformyl)urea were added. The resulting mixture was stirred for one hour at room temperature, and the mixture was evaporated in vacuo to an oil. Water (20 ml.) was added to the oil, and the pH of the resulting mixture was raised to 8.0 by addition of aqueous sodium bicarbonate. The resulting mixture was washed with ethyl acetate, and the pH of the aqueous layer was lowered to 2.0 - 38 41590 by addition of IN hydrochloric acid. The resulting precipitate was filtered off and dried to obtain 118 mg. of 7-a[3- ( methylaminocarbonyl)-3-methyl-l-ureido[phenylacetamido-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid.

NMR, DMSO dg-CDjOD: 7.43 (b, 5H, CgHg); 5.76 (d, IH, 7a-H); 5.61 (s, IH, CgHg-CH); 5.05 (d, IH, 6a-H); 4.16 (m, 2H, 3-CH2); 3.64 (b, 2H, 2-CH2); 3.39 (s, 3H, triazine N-CH3); 3.15 (s, 3H, CO-N(CH3)-CO); and 2.75 ppm (s, 3H, CONH(CH3)).

Example 12 To 25 ml. of dry THF were added 554 mg. (1.1 mmole) of 7-(α-amino)phenylacetamido-3-(4-methyl-5-oxo6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3cephem-4-carboxylic acid and 650 mg. (5 mmole) of N-trimethylsilylacetamide. The mixture was stirred for three hours until dissolution occurred. Tin* solution thou was cooled to 0°C., and 650 mg. (5 mmole) of 1-chloroformylimidazolidin-2-one were added. The resulting mixture was stirred for 30 minutes at 0°C. and then for 1 hour at room temperature. Water (2 ml.) then was added to the mixture. The mixture then was evaporated in vacuo to an oil. Water (25 ml.) was added to the oil, and the pH was raised to 7.5 with sodium bicarbonate. The solution was washed with ethyl acetate, and the aqueous layer then was acidified to pH 1.8 by addition of IN hydrochloric acid. The resulting solid was filtered off and triturated with methanol, and the methanol insoluble matter was filtered off. resulting methanol solution was slowly evaporated in vacuo The - 39 41590 to an oil. Water (25 ml.) was added to the oil, and the pH was raised to 7.5 with sodium bicarbonate. The solution was washed with ethyl acetate, and the aqueous layer then was acidified to pH 1.8 by addition of IN hydrochloric acid.

The resulting solid was filtered off and triturated with methanol, and the methanol-insoluble matter was filtered off. The resulting methanol solution was slowly evaporated in vacuo until precipitation resulted. The precipitate was filtered off and dried to obtain 92 mg. of 7-a-(imidazolidin-2-on-l-ylcarbonylamino)phenylacetamido-3-(4-methyl-5-oxo-6-hydroxy4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem-4carboxylic acid.

NMR, DMSO dg-D2O: 7.5Q (b, 5H, CgHg); 5.75 (d, 1H, 7a-H); .60 (s, 1H, CgHgCH); 5.02 (d, IH, 6a-H); and 3.36 ppm (s, 3H, triazine N-CHj).

Example 13 To 20 ml. of dry THF were added 554 mg. (1.1 mmole) of 7-(α-amino)phenylacetamido-3-(4-methyl-5-oxo-6-hydroxy4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem-4carboxylic acid and 650 mg. (5 mmole) of N-trimethylsilylacetamide. The mixture was stirred for about three hours after which dissolution was complete. The soLution then was cooled to 9eC., and 339 mg. (1.5 mmole) of 1-chloroformyl-3-methanesulfonylimidazolidin-2-one were added. The reaction mixture was stirred for about 30 minutes at 0°C. and then for about 1.5 hours at room temperature. Water (2 ml.) was added to the mixture. The solution then was evaporated in vacuo to an oil. Water (25 ml.) then was added, and the pH of the mixture was raised to 7.5 by addition of sodium bicarbonate. The solution then was - 40 41590 washed with ethyl acetate, and the aqueous layer was separated and acidified to pH 1.8 by addition of IN hydrochloric acid. The solid which precipitated was filtered off and dried to obtain 416 mg. of 7-ct-(3-methanesulfonylimidazolidin-2-on-l-ylcarbonylamino)phenylacetamido-3(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-.i-ylthio)methyl-3-cephem-4-carboxylic acid.

NMR, DMSO dg-D2O: 7.47 (b, 5H, CgHg); 5.75 (d, 1H, 7a-H); 5.71 (s, 1H, CgHgCH); 5.02 (d, 1H, 6a-H); 3.87 (b, 4H, N-CH2-CH2-N); and 3.37 ppm (b, 6H, triazine N-CH^ and SC^CH^).

Example 14 To 20 ml. of dry tetrahydrofuran (THF) were added 1.53 grams (10 mmole) of hydroxybenzotriazole and 2.57 grams (10 mmole) of a-(t-butoxycarbonylamino)thien-2-ylacetic acid. The mixture was cooled to 0°C., and 2.06 grams (10 mmole) of Ν,Ν'-dicyclohexylcarbodiimide were added. The mixture was stirred with ice bath cooling for 2.75 hours. The mixture then was filtered rapidly, and the solids were washed with 10 ml. of dry THF. The filtrate and washings which wore collected were maintained in an ice hath.

To 60 ml. of dry THF containing 9.8 grams (75 mmole) of N-trimethylsilylacetamide were added 3.73 grams (10 mmole) of 7-amino-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-1,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid. The mixture was sonicated(i.e. mixed by means of sound waves) for about 1 hour, during which time almost complete dissolution occurred. The resulting solution then was stirred’in an ice bath, and, after 15 minutes, was added rapidly to the above-prepared filtrate containing the acylating agent. The resulting mixture was stirred with ice bath cooling for 30 minutes and then at - 41 41590 32°C. for three hours. The resulting brown solution was poured rapidly into stirred ice water. Ether was added, and the pH of the aqueous phase was adjusted to 8.2. The phases were separated, and the water layer was washed with a further volume of ether. The aqueous phase then was subjected to rotary evaporation to remove residual ether.

Ice was added to the resulting aqueous solution, and the mixture was stirred rapidly while the pH was adjusted to 1.8 by addition of IN hydrochloric acid. The resulting mixture was filtered, and the solid was washed with dilute hydrochloric acid (pH 1.8), air-dried, and dried in vacuo to give 4.16 grams Of 7-[a-(t-butoxycarbonylamino)thien-2ylacetamido]-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid as a pale, yellow-brown solid.

NMR, TFA dx: 7.97, 7.48 and 7.17 (m, 3H, thienyl); 5.86 (b, 2H, 7a-H and 7-CH); 5.21 (b, lH, 6a-H); 4.44 (q, 2H, 3-CH2); and 3.7-3.5 ppm (b, 5H, 2-CH2 and triazine N-CH3).

Example 15 The product from Example 14 (1.60 grams) was placed in a flask equipped with a stirrer bar. The flask then was cooled in an ice-acetone bath. To the flask then were added rapidly 60 ml. of trifluoroacetic acid which had first been cooled in an ice-acetone bath. The resulting mixture was stirred for 15 minutes during which time complete dissolution occurred. Thin-layer chromatography (TLC) of the mixture indicated that the reaction was complete. The reaction mixture then was rotary evaporated to a gum.

Ethyl acetate (60 ml.) was added to the gum, and the mixture - 42 41590 wao sonicated, resulting in a powder which was collected by filtration, washed with ethyl acetate, and air dried to give 1.55 grams ol a Light brown powder. To Lhe powder was added a mixture of 75 ml. of water and 10 ml. of ethanol. The resulting mixture was sonicated, and the pH was adjusted to 1.4. The mixture was filtered, and the pH of the filtrate was adjusted to 3.7. The resulting mixture was again filtered, and the solid which was collected was washed with dilute acid (pH 3.8) the washings being added to the filtrate. Isopropyl alcohol then was added to the filtrate and the total was rotary evaporated to a small volume. Additional isopropyl alcohol was added to the residue, and the mixture was filtered. The collected solid was washed with a 1:1 mixture of water and isopropyl alcohol? maintained at a pH of 3.8. The resulting solid was dried to obtain 280 mg. of 7-(a-(amino)thien-2-ylaeetamido]-3-(4-methyl-5-oxo-6hydroxy-4,5-dihydro-l,2,4-triazin-3~ylthio)methyl-3cephem-4-carboxylic acid.

NMR, DMSO dg-DjO: 7.59, 7.25 and 7.08 (m, 3H, thienyl); 5.66 7-CH); 4.99 (d, IH, 7a-H); 5.38 (s, IH, (d, IH, 6a-H); and 3.28 ppm (bs, 3H, triazine N-CH^).

Example 16 To 24 ml. of dry tetrahydrofuran were added 408 mg. (0.8 mmole) of the product from Example 15 and 917 mg. (7 mmole) of N-trimethylsilylacetamide. Dissolution was complete within 10 minutes, and, after 15 minutes, the solution was placed in an ice bath. Propylene oxide (1.6 ml.) and sodium bicarbonate (65 mg.) were added followed by 145 mg. (0.96 mmole; 1.2 mole equivalent) of N-chloro- 1 - 43 41590 formyl-N,N'-dimethylurea. The resulting mixture was removed from the ice bath and stored at room temperature for 20 minutes. The mixture then was rotary evaporated to a small volume (about 10 ml.), and ice water was added. The re5 suiting suspension then was stirred, and the pH was adjusted to 6.5. The resulting solution was washed with twice the volume of ether, and the aqueous phase then was rotary-evaporated until the ether was removed. The aqueous mixture then was acidified to pH 1.7, and the resulting solid was collected by filtration and partially dried on the filter. The damp product then was dried in vacuo to give 96 mg. of 7-[a-(3methyl-3-methylaminocarbonyl-l-ureido)thien-2-ylacetamido]3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-3ylthio)methyl-3-cephem-4-carboxylic acid as a pale yellowiS brown powder.

NMR, DMSO dg-D2O: 7.43, 7.10 and 7.01 (m, 3H, thienyl); .79 (s, IH, 7-CH); 5.70 (d, IH, 7cx-H) ; .05 (d, IH, 6a-H); 3.65 (m, 2H, 2-CH2); 3.27 (s, 3H, triazine N-CH3,; 3.03 (s, 3H, CO-N(CH3)-CO); and 2.67 ppm (3, 3H, CONH(CH3)).

Example 17 Employing the same procedure as described in Example 16 but replacing the N-chloroformy1-N,N1-dimethyl25 urea with 217 mg. (0.96 mmole) of l-chloro£ormyl-3-methanesulfonylimidazolidin-2-one gave 242 mg. of 7-fa-(3methanesulfonylimidazolidin -2-on-l-ylcarbonylamino) bhien2-ylacetamido]-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydrol,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid. - 44 41590 NMR, DMSO dg! 9.52 (d, 1H, NH); 8.72 (d, 1H, NH) ; 7.45, 7.10 and 6.99 (m, 3H, thienyl); 5.88 (d, 1H, 7-CH); 5.74 (q, 1H, 7a-H); 5.08 (d, 1H, 6a-H), 4.08 (m, 2H, 3-CH2), 3.78 (b, 4H, N-CH2~CH2-N), 3.60 (m, 2H, 2-CH2); 3.34 and 3.28 ppm (two s, 6H triazine, N-CH^ and SOjCH-j) .

Example 18 To 15 ml. of dry THF were added 317 mg. (0.5 mmole) of the trifluoroacetate salt of 7-(a-amino-4-hydroxyphenylacetamido)-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4triazin-3-yIthio)methyl-3-cephem-4-carboxylic acid. N-Trimethylsilylacetamide (0.59 grams) was added to the resulting suspension. The mixture was stirred for two hours at room temperature after which dissolution resulted. The mixture then was cooled to 0°C., and 50 mg. of triethylamine and 1 ml. of propylene oxide were added. To the mixture then were added 123 mg. (0.5 mmole) of N-(o-chlorobenzoyl)-N-(chloroformyl)methylamine. The resulting solution then was stirred at room temperature for 1.5 hours after which the reaction mixture was filtered. Water (1 ml.) was added to the filtrate; however, no precipitation occurred. The mixture then was evaporated in vacuo to about 10 ml., and 50 ml. of ethyl acetate were added,followed by 50 ml. of water. The pH of the mixture was raised to 7.5 by addition of sodium bicarbonate. The ethyl acetate layer then was separated from the aqueous layer. Fresh ethyl acetate (50 ml.) and THF (15 ml.) were added to the aqueous layer, and the pH of the aqueous layer was lowered to 2.5 by addition of IN hydrochloric acid. The organic layer was separated from the aqueous layer, dried over magnesium sulfate, and filtered. The - 45 41590 filtrate then was evaporated in vacuo to about 10 ml-, and 20 ml. of ether were added. The mixture then was filtered to obtain 150 mg. of 7-[a-[3-(2-chlorobenzoyl)-3-methyl-lure ido]-4-hydroxyphenylacetamido]-3-(4-methyl-5-oxo-65 hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem4-carboxylic acid.

NMR, DMSO 7.35 (b, 4H, o-chlorobenzoyl); 6.96 (<·, 4H, p-hydroxyphenyl); 5.83 (q, 1H, 7a-H); 5.47 (d, 1H, 7-CH); 4.99 (d, 1H, 6a-H); 4. 3 (m, 2H, 3-CH2)! 3.56 (m, 2H, 2-CH2); and ;.3 ppm (b, 6H, triazine N-CH3 and CO-N(CH3)-CO).

Example 19 To 25 ml. of dry THF containing 1.18 grams (9 mmole) of N-trimethylsilylacetamide were added 634 mg. (1.0 mmole) of the trifluoroacetate salt of 7-(cc-amino-4-hydroxyphenylacetamido)-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro1,2,4-triazin-3-ylthio)methyl-3-oephem-4-carboxylic acid, dissolution occurred within 15 minutes of completion of the addition of the cephalosporin compound. The resulting solu20 tion then was cooled to 0°C. in ice-acetone, and 84 mg. (1 mmole) of sodium bicarbonate were addedfollowed by 1 ml. of propylene oxide. To the resulting mixture then were added 226 mg. (1 mmole) of l-chloroformyl-3-methanesulfonylimidazolidine-2-one. The reaction mixture was warmed to room ' temperature and stirred at room temperature for 1.5 hours.

The reaction mixture then was filtered, and 1 ml. of water was added to the filtrate. No precipitation occurred. The mixture then was evaporated in vacuo to about 10 ml., and 100 ml. of a 6:1 mixture of ethyl acetate and THF^ along with 50 ml. of water were added. The pH of the mixture was - 46 41590 raised to 7.0 by addition of sodium bicarbonate. The aqueous layer then was separated from the organic layer, and the pH of the aqueous layer was lowered to 2.0 by addition of IN hydrochloric acid. The mixture then was filtered, and the collected solid was washed with isopropyl alcohol and dried to obtain 382 mg. of 7-[a-(3-methanesulfonylimidazolidin -2-on-l-ylcarbonylamino)-4-hydroxyphenylacetamidoJ-3-(4methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid.

NMR, TFA d^: 7.27 (q, 4H, p-hydroxypheny1); 5.90 (d, IH, 7a-H); 5.73 (s, IH, 7-CH); 5.19 (d, IH, 6a-H); 4.46 (q, 2H, 3-CH2); 4.08 (b, 4H, N-CH2~CH2-N); 3.7-3.5 (b, 5H, 2-CH2 and triazine N-CH^); and 3.44 ppm (s, 3H, SO2CH3).

Example 20 Using the procedure of Example 18 but employing' twice the quantities of solvents and reagents, the cephal osporin derivative was reacted with 151 mg. (1 mmole) of N-chloroformyl-N,N'-dimethylurea in the presence of sodium bicarbonate instead of the triethylamine used in Example l8,to obtain 154 mg. of 7-[a-(3-methylaminocarbonyl3-methyl-l-ureido)-4-hydroxyphenylacetamido]-3-(4-methyl5-oxo-6-hydroxy-4,5-dihydro-l,2,4-trxazin-3-ylthio)methyl3-cephem-4-carboxylic acid.

NMR, DMSO dg-DjO: 7.08 (q, 4H, p-hydroxyphenyl); 5.72 (d, IH, 7a-H); 5.41 (ε, IH, 7-CH); 5.03 (d, IH, 6a-H); 4.1 (m, 3-CH2>; 3.36 (s, 3H, triazine N-CH3); 3.13 (s, 3H, CO-N (CH3)CO); and 2.73 ppm (s, 3H, CONH(CH3)). - 47 41590 Example 21 Employing the procedure of Example 20 but employing l-chloroformylimidazolidin-2-one as acylating agent, there was obtained 120 mg. of 7-[a-(imidazolidin5 2-on-l-ylcarbonylamino)-4-hydroxyphenylacetamidoJ-3-(4methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-3ylthio)methyl-3-cephem-4-carboxylic acid.

NMR, DMSO dg-D^O: 7.13 (q, 4H, p-hydroxyphenyl); 5.79 (d, IH, 7a-H); 5.51 (s, IH, 7-CH); 5.06 (d, ' IH, 6a-H); and 3.39 ppm (s, 3H, triazine N-CHj).

Claims (29)

1. CLAIMS:1. A cephalosporin of the formula X: in which R^ is hydrogen or lower alkyl; R 2 is hydrogen, an 5 alkali metal cation, or a readily removable ester forming II group; and R is hydrogen or the group R'-C- in which R* is hydrogen; C^-Cg alkyl; C^-C^ haloalkyl; C^-C^ cyanoalkyl; azidoalkyl; hydroxyalkyl; £-nitrobenzyloxy; 4-amino-4-carboxybutyl; a 4-substituted-amino10 4-esterified carboxybutyl group of the formula II A~O-C-CH-(CH ) “CH “ j 2 2 2 NH A’ in which A is diphenylmethyl, p-nitrobenzyl, benzyl, 2,2,2trichloroethyl, t-butyl, or p-methoxybenzyl and A' is C 2 -C 4 alkanoyl, C 2 ~C 4 haloalkanoyl, benzoyl, halobenzoyl, 15 2,4-dinitrophenyl, or phthaloyl; or R 1 is a group of the formula - 49 41590 in which a and a* independently are hydrogen, C^-C^ lower alkyl, C^-C^ lower alkoxy, halogen, hydroxy, nitro,or am inomethyl Z is 0 or S; and m is 0 or 1; or R* is a group of the formula P-CHI δ in which P is 2-thienyl, 3-thienyl, 1-tetrazolyl, or a phenyl group of the formula in which a and a· are as defined above; and Q is hydroxy, formyloxy, acetoxy, carboxy, sulfo, amino, or -NHY in which Y is benzyloxycarbonyl, t-butyloxycarbonyl, 0 '0 R ” » 0 II II I ' 8 -C-NH-C-NH-, or -C-N-C-V in which R> 1 ’ is hydrogen or II 2 NH C^-Cj alkyl, and, V is phenyl, halophenyl, furyl, mono- or di(Cj-C 3 alkyl) amino, or mono- or diphenylamino, or R” ’ and V, taken together with the group to which they are attached, form a heterocyclic group, R’” being -(CH„) - in ί* n which n is 2 or 3, and V being -NR ,,, ’- J in which R’ 1 ” is hydrogen, methanesulfonyl, or C^-C^ alkyl; or R’ is a group of the formula R^-GHg- in which R’’ is 2-thienyl; 3-thienyl; 2-furyl; 2-oxazolyl; 2-thiazolyl; 1-tetrazolyl} benzotriazolyl; 1,3j4-thiadiazolyl-2-thio; 1,2,5-thiadiazolyl 3-thio; 1,3,4-oxadiazolyl-2-thio; pyridyl-thio; l-(4-cyano)~ 1,2,3-triazolyl; or 1-(3-cyano)-l,2,4-triazolyl, provided that when R^ is lower alkyl, Rg is hydrogen or an alkali - 50 41590 metal, cation, and R is the group R* (i) R’ is not CJ^-iCj-Cj alkyl), C 2 or haloalkyl, cyanomethyl., C 2 or azidoalkyl, C 2 or hydroxyalkyl or benzyl optionally substituted by one or two C^-C^ lower alkyl, C -C. lower alkoxy, halogen or hydroxy groups, (ii) 1 4 when R' is the group of formula P-CH-and P is 2-thienyl, 3-thienyl, 1-tetrazolyl or phenyl optionally substituted by one or two Cj-C^ lower alkyl, C^-C^ lower alkoxy, halogen or hydroxy groups, Q is not hydroxy,carboxy, sulfo or amino, and (iii) when R> is a group of formula R’’-CH 2 -, R 11 is not 2. -thienyl, 3-thienyl, 2- furyl, 2-oxazolyl, 2-thiazolyl, 1-tetrazolyl or pyridylthio, and provided that when R^ is ethyl, R is other than hydrogen.

2. Λ cephalosporin according to claim 1 wherein R^ j s methyl or ethyl.

3. A cephalosporin according to claim 1 or 2 wherein R 2 is hydrogen or an alkali metal cation.

4. A compound according to claim 1, 2 or 3 where R is R*—t— in which R* represents the group: in which a, a>, Z and m are as defined in claim 1.

5. A cephalosporin according to any one of claims 1 to 3 wherein R represents’a group of formula R’^H^C-, R' ' representing a 2-thienyl, 3-thienyl, 2-furyl or 1-tetrazolyl group.

6. A cephalosporin according to any one of claims 1 to 3 wherein R represents a group of formula P-CH-C-, P being 1I Q - 51 41590 tetrazolyl, or a phenyl group of the formula, a . where a and a’ are defined in Claim 1, and Q is hydroxy, formyloxy, acetoxy, carboxy, or amino, 5

7. · Λ cephalosporin according to any one of claims 1 to 3 wherein R represents hydrogen.

8. 7-Amino-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro~ 1,2,4-triazin-3-ylthio)-methyl-3-cephem-4-carboxylic acid.

9. 7-(2,5-Diehlorophenylthio)acetamido-3-(4-methyl10 5-oxo-6~hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)mcthyl -3-cephem-4-carboxylic acid.

10. 7-(2,5-Dichlorophenylthio)acetamido-3-(4-®thyl-5oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)methyl3- cephem-4-carboxylic acid. 15

11. 7-(a-Formyl0xy)phenylacetamido-3-(4-methyl-5-oxo6-hydroxy-4,5-dihydro-1,2,4-triazin-3-ylthio)methyl-3-cephem4- carboxylic acid,

12. 7-u-[3-(4-chlorobenzoyl )-3-mothyl-l-ureido]phonylacetainid<)-3-(4-m

13. · 7-a-[J-(2-Chlorobenzoyl)-3-methyl-l-ureido]phenyla cet ami do-3-(4-methyl-5-0xo-6-hydroxy-4,5-dihydro-l,2,4triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid.

14. 7-a-(3-Furoyl-l-ureido)-phenylacetamido-3-(4-mebhyl-552 41590 oxo-fi-liyd i'oxy-4,5-d i hydro- 1,2,4-tr i azin-3-y I Lh io )methyI 3-c:ephcm-4-carboxy I ic acid .

15. 7-a-^3-Methylaminocarbonyl)-3-methyl-l-ureidoJ phenylacetamido-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro5 l,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid.

16. 7-a-(lmidazoldin-2-on-l-ylcarbonyl-amino)phenylacetamido 3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio) mothyL-3-cephem-4-carboxylic acid.

17. 7-a-(3-Methanesulfonyl-imidazolidin-2-on-l-ylcarbonyl10 amino)phenylacetamido-3-(4-methyl-5~oxo-6-hydroxy-4,5dihydro-1,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid.

18. . 7-£ a -(3-Methyl-3-methylaminocarbonyl-l-ureido) thi en-2~ytacetamid

19. 7-|«-(3-Methanesulfonylimidazolidin-2-on-l-ylcarbonylamino)thien-2-yiacetamido]-3-(4-inethyl-5-oxo-6-hydroxy-4,5dihydro-1,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic 20. Acid.

20. 7-[a~ [3-(2-Chlorobenzoyl-3-methyl-l-ureid0] -4-hydroxy» phenylacetamidp2-3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro1,2,4-triazin-3-ylthio)mothyL-3-cephem-4-carboxylic acid.

21. · 7-|ά-(3-Methanesulfonylimidazolidin-2-on-l-ylcarbonyl25 amino)-4-hydroxyphenylacetamido| -3-(4~methyl-5-oxo-6-hydroxy4,5-dihydro-l,2,4~triazin-3-ylthio)methyl-3-cephem-4carboxylic acid.

22. 7—(a -(3-Methylaminocarbonyl-3-methyl-l-ureido)-453 41590 hydroxyphenylacetamido]-3-(4-methyl-5-oxo-6-hydroxy-435dihydro-l,2,4-triazin-3-ylthio)methyl_3-cephem-4-carboxylic acid.

23. · 7-|g -(Imidazolidin-2-on-l-ylcarbonylamino)-4-hydroxy5 phenylacetamidcj -3-(4-methyl-5-oxo-6-hydroxy-4,5-dihydro1,2,4-triazin-3-ylthio)methyl-3-cephem-4-carboxylic acid.

24. · 7-(p-Aminomethylphenyl)acetamido-3-(4-methyl-5oxo-6-hydroxy-4,5-dihydro-l,2,4-triazin-3-ylthio)metbyl-3cephem-4-carboxylic acid. 10

25. A process for preparing a cephalosporin compound of fot'mula I as claimed in any one of tho preceding claims, which comprises reacting a 3-acetoxyinothyl-cophalosporln compound of formula II: II coor 2 15 with a mercaptotriazine derivative of the formula optionally acylating the compound of formula I so obiained wherein R is hydrogen or Q is amino; and, if desired, removing the amino protecting group A and the carboxy protecting group A, or the amino protecting group Y, where Y is benzyloxycarbonyl or t-butyloxycarbonyl, and/or the carboxy protecting group R 2 , where R 2 is a readily removable ester-forming group.

26. A process according to claim 25 for preparing a - 54 41590 cephalosporin compound of formula I, substantially a.s hereinbefore described with particular reference to any one of Examples 1,3,5 and 6, to Examples 3 and 4, to Examples 1, 2 and 7,8,9,11,12 or 13, to Examples 3,4, and 14 to Examples 5 3,4,10 and any one of l8 to 21, or to Examples 3,4,14,15 and l6 or 17·

27. · A cephalosporin compound of formula I as defined in claim 1, substantially as hereinbefore described with particular reference to any one of Examples 1,3 to 9, 11 10 to 14 and l6 to 21.

28. A cephalosporin of formula I whenever prepared by a process according to claim 25 or 26.

29. A pharmaceutical formulation comprising an antibiotieally active compound of formula I as claimed in 15 any one of claims 1 to 24, 27 and 28, associated with a pharmaceutically carrier therefor.