Synthesis of cephalosporins with substituted thiadiazoles directly attached to the C3-position.

Abstract

Synthesis of cephalosporins with substituted thiadiazoles directly attached to the C3-position starting from 3-formylceph-3-em derivative (1) is described. Thiocarbonylhydrazones of 1 were readily cyclized to the corresponding thiadiazole derivatives (3) by treating with 2, 3-dichloro-5, 6-dicyanobenzoquinone (DDQ).