Method of preparation of isomers synthesis of compounds of acids (3,7 - cephem - 4 - carboxylic 3,7 - disubstituted and novel products thus obtained, for anti-bacterial effect

摘要

Novel syn-isomer of 3,7-disubstituted-3-cephem-4-carboxylic acid compounds are provided of the formula: IMG in which R1 is a group of the formula: IMG wherein R5 is hydrogen, halogen, nitro, hydroxy, lower alkoxy or acyloxy and R6 is hydroxy, lower alkoxy, acyloxy, acylamino or di(lower)alkylamino; a group of the formula: IMG wherein R7 is amino, protected amino, hydroxy or lower alkyl; or a group of the formula: IMG wherein R8 is lower alkyl and R9 is imino, protected imino or oxo; R2 is an aliphatic hydrocarbon group which may have suitable substituent (s); R3 is carboxy or protected carboxy; and R4 is acyloxymethyl, hydroxymethyl, formyl or a heterocyclicthiomethyl group which may have suitable substituent (s); or R3 and R4 are linked together to form -COOCH2-, and pharmaceutically acceptable salts and tautomers thereof; the novel compounds are highly active against a number of pathogenic bacteria.