| 摘要 |
NEW MATERIAL:A compound of formula I [R<1> is (protected) amino; R<2> is organic group; R<3> is H, lower alkyl, (protected) hydroxy lower alkyl, (protected) amino lower alkyl or imino-protecting group; R<4> is H or lower alkyl(thio); A is (substituted lower alkylene; Z is N or CH] and a salt thereof. EXAMPLE:7beta-[2-(5-amino-1,2,4-thiadiazol-3-yl)-2-(1-carboxy-1-methyl ethoxyimino) acetamido]-3-[2,3-dihydro-5-(1H-imidazo[1,2-b]pyrazolio)]methyl-3-ceph em-4- carboxylate (sym isomer). USE:An antibiotic. PREPARATION:A compound of formula II, a reactive derivative thereof at the amino group or a salt thereof is reacted with a compound of formula III, a reactive derivative thereof at the carboxyl group or a salt thereof. |
