Connlab Holdings Limited

Peter K Wolfert

Ronald G Micetich

Chia-Cheng Shaw

Nicholas Darby

A process for preparing 2-acyloxymethylpenams and 3-acyloxycephams of the formulae 1 and 2 ##STR1## in which R represents the aliphatic, aromatic, or heterocyclic moiety of an amino-protecting group commonly employed in penicillin chemistry, R.sup.1 is hydrogen or represents a carboxy-protecting group commonly employed in penicillin chemistry, and R.sup.2 is hydrogen, C.sub.1 -C.sub.6 alkyl which may also be substituted with Cl, OCH.sub.3, or CN, and phenyl which may also be substituted with CH.sub.3, F, Cl, OCH.sub.3 or NO.sub.2, by treating an unsym-azetidinone disulfide of the formula 3 ##STR2## in which R and R.sup.1 are as defined above and R.sup.4 is benzothiazol-2-yl or benzoxazol-2-yl with silver oxide, an acid of the formula R.sup.2 COOH, and iodine, or with a silver salt of the formula R.sup.2 COOAg and iodine, or with a Simonini complex of the formula R.sup.2 COOI.R.sup.2 COOAg, to obtain a mixture of the compounds of formulae 1 and 2, and optionally separating said mixture.

Process for preparing 2-acyloxymethylpenams and 3-acyloxycephams

Thiazolineazetidinone derivatives of the formulae 1,2, and 3. ##STR1## wherein R is derived from the commonly known carboxamido groups present in penicillins, R.sup.1 is a carboxy protecting group commonly used in penicillin chemistry, and R.sup.2 is Cl, Br, I, CN, lower alkoxy, lower acyloxy, SCN, SCH.sub.3, S-phenyl, S-heteroaryl such as 5-mercaptotetrazole or 2-mercapto-5-methyl-1,3,4-thiadiazole, NO.sub.3, N.sub.3, NH-phenyl, and N(CH.sub.3).sub.2 with the proviso that R.sup.2 in the compounds of formula 1 is limited to Cl, Br, I, and lower acyloxy, and a process for preparing said compounds from 2-(substituted methyl) penicillin sulfoxides followed by treatment with a base. The compounds of formulae 1,2, and 3 are useful as intermediates in the synthesis of cephalosporins.

Growing community of inventors

Edmonton, Canada

Peter K Wolfert