Animal bone meal as a new efficient heterogeneous catalyst for the synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones

Animal bone meal has been used as an efficient catalyst for an improved and rapid one-pot synthesis of 3,4-dihydropyrimidin-2(1H)-ones/thiones and their derivatives through three-component condensation reactions of aldehyde, beta-ketoester, and urea or thiourea in excellent yields. This catalyst was found to be highly active and selective, affording a high yield of 3,4-dihydropyrimidin-2(1H)-ones/thiones. These reactions were performed via conventional heating in water or under microwave irradiation. Compared to the classical Biginelli reaction conditions, this new approach consistently has the advantage of excellent yields, short reaction times, simple and convenient procedure, inexpensive reagents and eco-friendly preparation.