3-Carbamoyloxy-methyl-7-thiazolyl-acetamido cephalosporin derivs. - prepd. from 3-acetoxymethyl cpd. by enzymatic de-acetylation and reaction with isocyanate, useful as antibiotics

摘要

Parent patent describes new cephalosporins of formula (I), syn or anti, where R = H or gp. easily removed by acid hydrolysis or hydrogenolysis. R1 = 1-4C, opt. unsatd. alkyl. A = H or an equiv. of an alkali, alkaline earth, Mg or amine cation. This addition describes the prodn. of (I) from cpds. (V) (where R1 = R other than H) by (i) enzymatic deacetylation; (ii) reaction with R2NCO (R2 = gp. easily removed by hydrolysis) then (iii) hydrolysis to give (I; R = R1), opt. followed by removal of R1 to give (I; R = H). In an alternative R1 is replaced by chloroacetyl which is removed in the final stage with thiourea. Also new are the Na salt of the syn isomer of 3-carbamoyloxymethyl-7- 2-(2-amino-4-thiazolyl)-2-methoxyimino-ac- etamido -ceph-3-en-4-carboxylic acid. (Ia); and intermediates of formula (II) (where Q is chloroacetyl and D is H or CONHR2, R2' = H or R2; or, Q is R1 and D is H or CONHR2). (I) are antibiotics useful against Gram positive or negative bacteria, including penicillin-resistant Staphylococci.