Synthesis of 3, 4- dihydropyrimidine-2-(1H)-ones (thiones) in the presence of an efficient and eco-friendly solid acid catalyst under different conditions

Multiple-component reactions (MCRs) such as biginelli reaction are powerful strategies for the one-pot synthesis of organic compounds such as dihydropyrimidinone derivatives (DHPMs). The first biginelli-like reaction was reported by Wang.1 Biginelli reaction involves the cyclo condensation of an aromatic aldehyde, α,β-ketoester and urea (thiourea). Biginelli products have potential in pharmaceutical applications such as anti-viral, anti-tumor, anti-bacterial, anti-inflammatory, anti-hypertensive and alpha antagonists.2 Nano solid acid catalysts, which are bridges between homogeneous and heterogeneous catalysts, exhibit higher activity and selectivity than their corresponding bulk materials.3 Heterogeneous catalysts have been applied in organic reactions in recent years. In this work, an efficient catalyst was used which is reusable, inexpensive, readily available, eco-friendly, without the use of harmful solvents. In this study, we report our results for the synthesis of 3,4-dihydropyrimidinones (thiones) via one-pot cyclo condensation of acetoacetates, aromatic aldehydes, and urea or thiourea using nanocatalyst under different conditions (Fig.1).