Structure-activity relations in cephalosporins prepared from penicillins. 1. 7.beta.-Acylamino derivatives of 3-benzyl- and 3-(3-pyridylmethyl)ceph-3-em-4-carboxylic acids
作者:Edward G. Brain、A. John Eglington、John H. C. Nayler、Neal F. Osborne、Michael J. Pearson、Terence C. Smale、Robert Southgate、Patricia Tolliday、Michael J. Basker、Sutherland Robert
DOI:10.1021/jm00218a018
日期:1977.8
tert-Butyl 7beta-aminoceph-3-em-4-carboxylates carrying either benzyl or 3-pyridylmethyl substituents at position 3 have been prepared by a multistep modification of the penicillin nucleus. Acylation of either amine, followed by deprotection, gave a range of new cephalosporins. The relationship between structure and antibacterial activity is discussed. D-Phenylglycine proved to be a preferred side
A class of .alpha.-carboxy-3-heterocyclicthio cephems have an unusually high level of antibacterial activity against a wide variety of Gram-positive and Gram-negative organisms.
A compound of formula (I) or a salt thereof:
wherein R' is an amino group, an azido group, or an acylamino group as found in antibacterially active penicillins or cephalosporins;
R2 is a hydrogen atom or a C1-4 alkyl group;
R3 is a hydrogen atom, or a C1-4 alkyl group optionally substituted by a carboxyl, carboxylic ester, hydroxy, C1-4 alkyloxy, acyloxy or heterocyclylthio group; and
R4 is hydrogen or a readily removable carboxyl protecting group.
The compounds wherein R1 is an acylamino group are found in known antibacterially active penicillins and cephalosporins and wherein R4 is a hydrogen, a pharmaceutically acceptable salting ion or an in vivo hydrolysable ester forming radical may be formulated in pharmaceutical compositions.
Processes for the preparation of the compound (I) are also described.