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

J Org Chem. 2024 Apr 5;89(7):4628-4646. doi: 10.1021/acs.joc.3c02903. Epub 2024 Mar 18.

Abstract

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