Facile synthesis and structure of novel 2,5-disubstituted 1,3,4-selenadiazoles

Abstract

The reaction of hydrazide with carbonyl chloride in the presence of sodium carbonates leads to the corresponding 1,2-diacylhydrazines [ 1a – t , R1C(O)NHNHC(O)R2, R1 = aryl, R2 = aryl or alkyl] in moderate to excellent yield (57–90 %). The latter reacts with 2,4-diphenyl-1,3-diselenadiphosphetane-2,4-diselenide (Woollins' reagent, WR ) in refluxing toluene to give a series of new 2,5-disubstituted 1,3,4-selenadiazoles ( 2a – t , 51–99 % yield). All compounds were characterized spectroscopically and six compounds were characterized crystallographically.