Ringtransformation von 3,1-Benzothiazin-2,4-dithionen mit Carbonsäurehydraziden zu substituierten 1,3,4-Thiadiazolen oder (in Gegenwart von Hydroxidionen) zu 3-Acylaminochinazolin-2,4-dithionen

摘要

The substituted 1,3,4-thiadiazoles4–14were prepared in one step by reaction of 3,1-benzothiazin-2,4-dithiones1and3withRCONHNH2(R=Me, Ph, substitutedPh, 4-Pyridyl, CONHNH2). Reaction of1with RCONHNH2in the presence of HO−leads to substituted quinazolin-2,4-dithiones18–20. Under the action of CS2the yield of19and20increases. Possible reaction mechanisms are disc