Synthesis and reactions of s-triazole-fused heterocycles

Abstract

Reaction of 5-aryl-3-chloro-4-phenyl-1,2,4-triazoles (1 & 2) with hydrazine hydrate afforded 5-aryl-3-hydrazino-4-phenyl-1,2,4,-triazoles (3 & 4 ). Ring closure of compounds 3 and 4 with aromatic and aliphatic acids, CS2, and PhNCS gave the s-triazole-fused ring systems 5-10, 13, 14, 15, and 16, respectively. On the other hand, the reaction of compounds 3 and 4 with nitrous acid gave tetrazole-fused ring system derivatives 11 and 12. Compounds 13 and 14 were subjected to Mannlch reacpon to give Mannich bases 17 and 18. Alkylation and Acylation of compounds 13 and 14 afforded the corresponding S-alkyl and. N-acyl derivatives 19-22, respectively. N­ Acylation and S-Alkylation were proved, beside spectral data, chemically via oxidation of the products with K.Mn04 in acidic medium. When sulphonyl derivatives 23 and 24 were allowed to react with aq. NaOH, the corresponding oxo-derivatives 27 and 28 were obtained and subjected to Mannich reaction to give Mannich bases 29 and 30. Compounds 13 and 14 were reacted with formaldehyde to give 2-hydroxymethyl derivatives 31 and 32. The fused heterocyclic systems 35-40 were obtained from the corresponding chloromethyl derivatives 33 and 34. Interaction of compounds 13 and 14 with ethylchloroacetate give ethyl S-[6)-diphenyl-s-triazolo-[4,3- b]-s-triazole-3-yl]thioglycolate (41) and ethyl S-[6-(p-chlorophenyl)-7-phenyl- 1,2,4-triazolo-[4,3-b]-s-triazole-3-yl] thioglycolate (42) respectively. Hydrazinolysis Of 41 and 42 with hydrazine hydrate afforded the corresponding hydrazides 43 and 44.Ring closure of hydrazide derivatives 43 and 44 with CS2 and CH3NCS afforded compounds 45-48, respectively. The hydrazide derivatives 43 and 44 were reacted with aldehydes to give the corresponding arylidenes 49-52. Most of the synthesized compounds have been tested for antimicrobial activity.