Dimroth-Type Ring Transformation of 1, 4, 6-Trisubstituted-2 (1H)-Pyrimidinethiones with Ammonia and Primary Alkyl Amines

Abstract

1, 4, 6-Trisubstituted 2 (1H)-pyrimidinethiones (Ia-k) underwent Dimroth-type ring transformation with ammonia and primary alkyl amines in the presence of silver perchlorate to afford 2-(N-substituted) aminopyrimidines (IIa, c, d, f, j, k) and pyrimidinium perchlorates (IIIa-c, e-j), respectively. Furthermore, pyrimidinium perchlorates (III) were converted into 2 (1H)-pyrimidinones (IV) in high yields by hydrolysis with concentrated hydrochloric acid.