Oxidative Desulfurization of Azole‐2‐thiones with Benzoyl Peroxide: Syntheses of Ionic Liquids and Other Azolium Salts

1-Alkyl-3-methylimidazole-2-thiones were prepared from amino esters in one pot and converted to inherently halide-free 1-alkyl-3-methylimidazolium benzoates by oxidation with benzoyl peroxide followed by a novel anion exchange. Also reported are the outcomes of exchanges with other anions, acidifications of the imidazolium benzoates to other salts, and extension of the method to the syntheses of 1,3-diphenylimidazolium and 3-methyl- and -butylthiazolium salts.(© Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)