尿囊素合成新工艺

研究了原料乙二醛在酸性、常压条件下,以氧化氮为催化剂,经催化氧化后得到的生成物无需另加酸性催化剂直接与尿素缩合制得尿囊素的新工艺。考察了氧化和缩合反应中反应温度、原料配比、反应时间等因素的影响,确定了适宜的合成条件:乙二醛质量分数为25%,酸醛物质的量比为0.25,氮醛物质的量比为0.17,乙醛酸与尿素的物质的量比为1∶4,氧化反应温度为45℃,时间为2 h,缩合反应温度为75℃,时间为3 h,在此条件下,尿囊素的收率为61.99%。

New process for allantion synthesis

The new process for allantion synthesis by the condensation of the reactant of glyoxal catalytic oxidation in the condition of acidity,atmospheric pressure and nitrogen oxide as the catalyst,with urea without adding the acid catalyst.The influences of reaction temperature,ratio of raw materials,reaction time and so on,are investigated in the oxidation and condensation reaction,and the appropriate conditions of oxidation and condensation are obtained:the mass concentration of glyoxal is 25%,the ratio of acid and aldehyde is 0.25,the ratio of nitrogen and aldehyde is 0.17,the reaction time is 2 h,the reaction temperature of oxidation is 45℃,the ratio of glyoxylic acid and urea in the oxidation reactant is 1∶4,the reaction temperature of condensation is 75℃,and the reaction time of condensation is 3 h,under this condition,the yield of allantoin is 61.99%.