SiO_2-BaCl_2 as a Highly Efficient and Reusable Heterogeneous Catalyst for the One-pot Synthesis of 3,4-dihydropyrimidin-2-(1H)- one/thione Derivatives Under Solvent-free Conditions

An efficient protocol for the synthesis of 3,4-dihydropyrimidin-2-(1h)-one/thione derivatives via multi-component coupling reaction of aromatic aldehydes, β-ketoester and urea or thiourea under solvent-free conditions using silica supported barium chloride as a catalyst is described. all prepared compounds with melting points, ir, 1h nmrand 13c nmr were identified. high yields, mild conditions, easy availability and reusability were some advantages of this catalyst.