5-甲氧基尿嘧啶的合成研究

以甲氧基乙酸甲酯和甲酸乙酯为原料 ,通过硫脲和尿素路线分别合成了化合物 5 甲氧基尿嘧啶 ,经比较 ,尿素路线为比较理想的合成方法。0 .1mol金属钠催化作用下 ,0 12mol甲氧基乙酸甲酯和等物质的量的甲酸乙酯在甲苯中进行克莱森酯缩合 ,控温于 2 0～ 2 5℃ ,所得中间产物在无水乙醇中与 0 12mol尿素加成 ,回流 9h ,得 5 甲氧基尿嘧啶 ,其收率由文献记载的2 6 8%提高到 4 7 9% ,产品质量分数 99%

Research on the Synthesis of 5-Methoxyuracil

The synthetic method of 5 methoxyuracil through two different reaction routes,using methyl methoxyacetate and ethyl formate as raw materials,was investigated: (1)Mixture of methyl methoxyacetate and ethyl formate in mol ratio 0 1∶0 12 condensed in toluene under catalysis of 0 1 mol of sodium,then reacted in methanol with 0 12 mol of thiourea by refluxing for 7 h to form 4 hydroxy 5 methoxy 2 mercaptopyrimidine in 54 4% yield,which after hydrolysis gave the target compound with total yield of 49 5%.(2)Catalyzed by 0 1 mol of sodium,0 1 mol of methyl methoxyacetate and 0 12 mol of ethyl formate condensed in toluene, the temperature being controlled around 20-25 ℃,then the intermediate product reacted with 0 12 mol of urea in ethanol by refluxing for 9 h to form 5 methoxyuracil in 47 9% yield(yield recorded in the literature was 26 8%).Purity of the product was 99%.