Microwave-Assisted One-Pot Telescoped Synthesis of 2-Amino-1,3-thiazoles, Selenazoles, Imidazo[1,2-a]pyridines, and Other Heterocycles from Alcohols

Abstract

Primary and secondary alcohols have been con-verted into 2-amino-1,3-thiazoles under microwave irradiation,employing trichloroisocyanuric acid (TCCA) as a dual oxidant andchlorine source, TEMPO as a co-oxidant, and thiourea. Secondaryalcohols underwent a single-stage, one-pot conversion process,while primary alcohols required a two-stage, one-pot procedure.Both transformations were completed within minutes (25−45min). The versatility of this protocol extends to the synthesis ofother heterocycles, including 1,3-selenazoles, 2-aminoimidazoles,imidazo[1,2-a]pyridines, quinoxalines, and hydrazino thiazoles byreplacing thiourea with the appropriate surrogates