H_4SiW_(12)O_(40)/SiO_2催化一锅法合成4-苯基-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮

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

采用一锅法Biginelli反应以H4SiW12O40/SiO2为催化剂,以苯甲醛、乙酰乙酸乙酯和尿素为原料,无水乙醇为溶剂合成了4-苯基-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮。探讨了原料摩尔比、反应温度、催化剂用量及反应时间对收率的影响。结果表明,固定苯甲醛用量为0.04 mol的条件下,n(苯甲醛)∶n(乙酰乙酸乙酯)∶n(尿素)=1∶1.5∶1.5,催化剂的用量占反应物料总质量的2.0%,反应温度为90℃,反应时间为60 min,产品平均收率可达71.7%。通过熔点的测定,IR,1HNMR和MS对合成的3,4-二氢嘧啶酮化合物进行了表征。

H4SiW12O40/SiO2 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 tool, 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.