杂多化合物催化合成尿囊素的研究

STUDY ON SYNTHESIS OF ALLANTOIN USING HETEROPOLY COMPOUND AS CATALYST

以乙二醛和尿素为原料 ,过氧化氢为氧化剂 ,采用具有酸碱催化和氧化还原催化双功能的K15H2 [Ce( P2 W15Mo2 O61) 2 ]杂多化合物为催化剂 ,系统地研究了尿囊素的合成条件 .其最佳工艺条件 :乙二醛的氧化温度为 3～ 8℃ ,尿囊素的生成温度是 75℃ ,乙二醛与过氧化氢的物质的量比为1 .0∶ 1 .1 ,催化剂与乙二醛的物质的量比为 2 .9× 1 0 -5∶ 1 .0 ,反应时间 8h,尿囊素收率为2 7.2 2 % 。

The compound K 15 H 2 [Ce (P 2W 15 Mo 2O 61 ) 2] was found to be an efficient environmentally friendly catalyst for the two step synthesis of allantoin: first oxidation of glyoxal by hydrogen peroxide and final condensation of carbamide with glyoxalic acid. The first step reaction was conducted at 3～8 ℃ for 6 h at a molar ratio of 1 0∶1 1 of glyoxal to hydrogen peroxide. The second step reaction was run at 75 ℃ and 0 25 g of the catalyst was used per molar glyoxal. Under the optimum conditions the yield is 27 22%.