Decatungstodivanadogermanic heteropoly acid (H6GeW10V2O40.22H2O): A green and reusable heterogeneous catalyst for the synthesis of Biginelli-type 3,4-dihydropyrimidin-2-(1H)-ones/thiones

Decatungstodivanadogermanic acid (H6GeW10V2O40.22H2O) was used as a green heterogeneous catalyst for the synthesis of 3,4-dihydropyrimidin-2-(1H)-ones from one-pot three-component cyclocondensation reaction of a β-ketoester, an aldehyde and urea/thiourea under solvent-free conditions is reported. This method provides an efficient and much improved modification of the original Biginelli reaction reported in 1893, in terms of high yields, and short reaction times. It has the ability to allow a wide variety of substitutions in all three components.