1-methyl-tetrazol-5-yl- (4-ethyl-2,3-dioxopirazin-1-yl) and tetrazole -carbonylthiolat (1,5-b) pyridazin-6-yl- (4-ethyl-2,3- dioxopiperazin-1-yl) -carbonylthiolat

摘要

Certain cephalosporins having a heterocyclicthiomethyl group at the 3-position such as cefoperazone are prepared by reacting a solution of a 7-acylamidocephalosporanic acid having a free amino group as part of said acyl substituent with about an equi-molar amount of the thiolester IMAGE wherein -S-Het is the desired conventional heterocyclicthio group which displaces the 3-acetoxy group of the starting acid and IMAGE is the conventional acyl group which displaces a hydrogen on the free amino group which is part of the acyl substituent of the starting 7-acylamidocephalosporanic acid.