A One-Pot Synthesis of 2-Amino- and 2-(Arylamino)-Substituted Thiazoles and Selenazoles using [Hydroxy(tosyloxy)iodo]benzene, Carbonyl Compounds and Thioureas or Selenoureas: A Modification of the Hantzsch Synthesis

A one-pot synthesis of 4-substituted 2-amino- or 2-(arylamino) thiazoles has been achieved via treatment of ketones with [hydroxy(tosyloxy)iodo]benzene and thioureas in refluxing acetonitrile. 1,3-Dicarbonyl compounds yield (5-acyl-4-methylthiazol-2-yl)-ammonium tosylates and the corresponding selenazol-2-yl compounds, respectively, upon reaction with [hydroxy(tosyloxy)iodo] benzene followed by the addition of thiourea or selenourea. The tosylate salts are converted to the corresponding free bases by treatment with sodium bicarbonate