Ionic Liquid Mediated Synthesis of Novel tetrahydroimidazo [1,2- a]pyrimidine-6-carboxylate Derivatives

Abstract

Abstract: A novel route for the synthesis of tetrahydroimidazo [1,2-a] pyrimidine-6-carboxylate derivatives in presence of 1-ethyl-3-methyl imidazolium hydrogen sulphate ionic liquid at room temperature has been reported via Biginelli reac-tion. The process offer several advantages such as short reaction time, excellent yield of products, simple work up proce-dure etc. 1-ethyl-3-methyl imidazolium hydrogen sulphate ionic liquid is utilized as solvent system and catalyst to en-hance the rate of reactions. Keywords: Aromatic aldehydes, Biginelli reaction, Catalyst, Ionic liquid, 5-amino-4,5-dihydro-1 H -pyrazole-4-carbonitrile. INTRODUCTION 3, 4-Dihydropyrimidine-2-(1 H )-ones and their deriva-tives are pharmacologically important because of having several potential biological activities including, antiviral, antibacterial, antitumor and antihypertensive agents. Fur-thermore, these compounds have emerged as the integral backbone of certain calcium channel blockers [1 - 6]. Recently to improve and modify the process, various syn-thetic methodologies for the preparation of such compounds have been developed using microwave irradiation [7-11], by using Lewis and Bronsted acids FeCl