| 摘要 |
GG252/256 7.beta.-¢¢¢(2-Cyanomethyl)amino!-1,2-dioxoethyl!amino!aacyl cephalosporins which have the formula wherein R is hydrogen, lower alkyl, phenyl-lower alkyl, diphenyl-lower alkyl, tri(lower alkyl)silyl, tri(lower alkyl)stannyl, trihaloethyl or a salt forming ion; R1 is hydrogen, lower alkyl, saturated or unsaturated cycloalkyl, phenyl, phenyl-lower alkyl, substituted phenyl or certain heterocyclic groups; R2 is hydrogen or methoxy; R3 is hydrogen, lower alkyl, phenyl-lower alkyl or cycloalkyl; R8 is hydrogen or -CR4R5-CN; R4 and R5 each is hydrogen or lower alkyl; and X is hydrogen, lower alkanoyloxy, carbamoyloxy, lower alkoxy, lower alkylthio , , or certain heterothio groups, are useful as antibacterial agents. |
