One-step synthesis of novel 2,2'-bi(4,5-dihydro-1,3,4-thiadiazole) and 2,3-disubstituted 1,4-benzothiazine derivatives

Article abstract of DOI:10.1016/S0040-4020(01)90419-3

N,N'-Diaryloxalodihydrazonoyl dihalides 2 react with potassium thiocyanate or thiourea and yield the hitherto unknown bi-4,5-dihydrothiadiazol-5-imine derivatives 5. Reaction of 5 with acetic anhydride, benzoyl chloride and nitrous acid yield N-acetyl, N-