A 1,2,3-thiadiazole–1,2,3-thiadiazole rearrangement

Abstract

During its preparation, 4-ethoxycarbonyl-5-diazomethyl-1,2,3-thiadiazole (4), undergoes a ring transformation into the isomeric structure (5), but when the ester function in (4) is replaced by a phenyl group, no isomerization is observed.