| abstract |
Pharmaceutically acceptable ester of 7-beta- (2- (2-amino-4-thiazolyl) -2-alkenoylamino) -3-cephem -4- carboxylic acid of the above formula: (where R is an amino radical or protected amino; R1 is a straight, branched cyclic, optionally alkoxylated, alkyl radical; R2 is a hydrogen atom or a 3-substituent of cephalosporins; R3 is a pharmaceutically acceptable ester radical, and X is a sulfur atom or sulfinyl radical. |