Reactions with sultones V*, synthesis of some new 5-membered heterocyclic sultams.

Triazoles 3a-d, oxadiazoles 4a,b and thiadiazoles 4c,d were obtained by different routes of cyclization of 2a-d depending on the reaction condition. Reaction of 1 with CS2, in boiling ethanol, gave the mercapto-oxadiazole 5; while the potassium thiocarbazide salt 6 was obtained when the reac tion takes place at r.t. 6 with hydrazine hydrate was cyclized to the amino-triazole 7. Triazolo-thiazoles 8a,b were formed when 7 reacted with either formic acid or acetic anhydride, respectively. Aroyl hydrazides 9a-d were obtained through reaction of 1 with the appropriate acid chloride. Cyclization of 9a-d using phosphorous oxychloride afforded the corresponding oxadiazoles 10a-d (Chart-1).