Synthesis of Fused s-Triazoles from 2-Methanesulfonyl-5-phenyl-1, 3, 4-oxadiazole and Binucleophilic Reagents by Means of Intramolecular Ring Transformation

Abstract

2-Methanesulfonyl-5-phenyl-1, 3, 4-oxadiazole (4) reacted with 3-aminopropanol and 2-aminoethanethiol in the presence of triethylamine to give displaced and rearranged products 2-(5, 6-dihydro-4H-1, 3-oxazin-2-yl)-(6b) and 2-(2-thiazolin-2-yl) benzhydrazide (9), which were further cyclodehydrated by heating to give the corresponding fused s-triazoles (7) and (10), respectively. In the case of the reaction with a diaminoalkane only the 1 : 2 adduct (8) was obtained.