Studies on Acetylenic Compounds. XXV.Ring Closure.(5). New Synthetic Method of Heterocyclic Compounds from α-Amino-and α-N-substitued Aminoacetylenic Compounds

Abstract

Anew ring closure of α-amino-and α-N-substituted aminoacetylenic compounds has been studied. 2-Methylimidazole and 2-thiazolethiol derivatives were easily synthesized by heating α-aminoacethylenic compound with thioacetamide and carbon disulfide, respectively. By treating 1-(2-propynyl)-urea, 1-(2-propynyl)-thiourea and 1-(2-propynyl)-benzamide with concentrated sulfuric acid, there were obtained 2-imidazolone, 2-imidazolethiole and 2-phenyloxazole derivatives, respectively.