1-Methylimidazolium hydrogen sulfate/chlorotrimethylsilane: An effective catalytic system for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones and hydroquinazoline-2,5-diones

Bronsted acidic ionic liquid, 1-methylimidazolium hydrogen sulfate, in the presence of catalytic amount of chlorotrimethylsilane has been used as an efficient and reusable catalyst for the one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones and hydroquinazoline-2,5-diones under thermal and solvent-free conditions. High yields of the products were obtained in a few minutes by using this new catalysis system. (C) 2012 Elsevier B.V. All rights reserved.