两相法合成4-苯基-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮

研究水作溶剂,三氯乙酸催化苯甲醛、乙酰乙酸乙酯、尿素在两相中缩合生成4-苯基-6-甲基-5-乙氧羰基-3,4-二氢嘧啶-2(H)-酮。最优工艺:n(苯甲醛25mmol)∶n(乙酰乙酸乙酯)∶n(尿素)=1.0∶1.5∶1.6,三氯乙酸3.0g,水7mL,无水乙醇3mL,反应温度60°C,反应时间4h,在此条件下产物的收率为91.6%。溶剂可重复使用。

Synthesis of 4-Phenyl-6-methyl-5-ethoxycarbonyl-3,4-dihydropyrimidin-2(H)-one Using a Two-phase Method

The synthesis of 4-phenyl-6-methyl-5-ethoxycarbonyl-3,4-dihydropyrimidin-2(H)-one by cyclocondensation of benzaldehyde,ethyl acetoacetate and urea in aqueous phase and in organic phase using trichloroacetic acid as catalyst and water as solvent was studied.The optimum conditions were as follows: n(benzaldehyde 25 mmol)∶n(ethyl acetoacetete)∶n(urea)=1.0∶1.5∶1.6;amount of trichloroacetic acid,3.0 g;volume of water,7 mL;volume of absolute alcohol,3 mL;reaction temperature,60°C;reaction time,4 h.The yield of the product was up to 91.6% under the above conditions.The solvent could be reused.