One-Pot Synthesis of 4-Phenyl-6-methyl-5-ethoxycarbonyl-3,4-dihydropyrimidin-2( H)-ketone Catalyzed by H_4SiW_(12)O_(40)/SiO_2

H 4 SiW 12 O 40 / SiO 2 exhibited excellent catalytic performance for the synthesis of 4-phenyl-6-methyl-5-ethoxycarbonyl-3,4-dihydro-pyrimidin-2( H)-ketone via one-pot Biginelli reaction from benzaldehyde,ethyl acetoacetate,and urea with anhydrous ethanol as solvent. The effects of the various reaction parameters on the yield of the product were investigated and the optimum conditions were determined as follows: fixed benzaldehyde consumption was 0. 04 mol,n( benzaldehyde) ∶ n( ethylacetoacetate) ∶n( urea) =1∶1. 5∶1. 5,the quantity of catalyst was 2. 0% of the feed stock,reaction temperature was 90 ℃,and reaction time was 1. 0 h. Under such conditions,the yield of the product was up to 71. 7%. The 3,4-dihydropyrimidin-2( H)-ketone was characterized by means of melting point measurements,IR,1HNMR and MS spectroscopy.