Oxidative Cyclization of Arylidene Carboxyhydrazides:Synthesis of Substituted Hydroxydiphenylmethyl-1,3,4-Oxadiazoles

The synthesis and characterization of a series of 5-aryl-1,3,4-oxadiazol-2-yl- diphenylmethanols (4) was achieved by oxidative cyclization of N -(3-aryl)methylene]-2-hydroxy- 2,2-diphenylacetohydrazides (3) with lead(IV) acetate. The S-{5-[hydroxy (diphenyl)methyl]-1,3,4- oxadiazol-2-yl}-aryl carbothioates (7) were prepared by the reaction of (5-mercapto-1,3,4- oxadiazol-2-yl)(diphenyl)methanol (5) with the respective acid chlorides.