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Abstract
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Imidazolium based hydrogen sulfate ionic liquid was prepared from the reactionof N-methylimidazole and (3-chloropropyl) trimethoxysilane. This ionic liquid was immobilized on silicacovalently to give nanoparticles with the imidazoliumhydrogen sulfate moiety remaining intact. The Biginelli reaction, 3,4-dihydropyrimidin- 2(1H)- thione, one-pot condensation of benzaldehyde derivatives, ethyl acetoacetate and urea/thiourea in presence of catalyst, was performed as a model reaction to examine the activity of this nanoparticle catalyst as proton source. Excellent performance was exhibited in the Biginelli reaction of various benzaldehyde derivatives in the presence of ethanol as solvent under mild heterogeneous conditions (room temperature and shortreaction time) and also in solvent free conditions.Compared with the classical Biginelli reaction, easy workup, mild conditions, reusability of catalysis, good to excellent yield and short reaction time areprivileges of this catalyst asefficient and green method. Productswere identified using physical and spectroscopic data, which have a captivatingassortment in natural, synthetic, pharmacological, therapeutic and bioorganic chemistry mainly due to their wide range of biological activities, and they are widely being studied because of their activities as calcium channel blockers, antihypertensive agents, alpha-la-antagonists and neuropeptide Y(NPY)antagonists
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