Silica gel supported bismuth nitrate penta-hydrate: A highly active catalyst under solvent free conditions towards the synthesis of dihydropyrimidin-2(1H)- ones and their sulphur analogues

摘要

Silica gel supported bismuth nitrate pentahydrate has been shown to be an efficient catalyst for the Biginelli reaction. The main advantages of the catalyst include short reaction time and high yield of the products. This observation has been confirmed by comparing the results using other catalysts like CuBr2, CuI and InCl3 with and without silica gel support. The reactions are carried out under solvent-free conditions.