PTSA/H_3PO_4复合酸催化合成尿囊素的研究

Study on the Synthesis of Allantoin with a Composite Acid of PTSA/H_3PO_4 as Catalyst

以一水乙醛酸和尿素为原料,在催化剂存在下,经环化缩合反应制备了医药和有机合成中间体及日化助剂尿囊素。研究表明,以对甲基苯磺酸-磷酸(PTSA-H3PO4)构成的复合酸作为催化剂,在75～80°C下环化反应6h,尿囊素收率可达60%以上。产品经元素分析,熔点测定、红外光谱表征并用滴定法测定其纯度,尿囊素含量在98%以上。

Allantoin, as intermediate for medicine, cosmetics and other organic compounds, was prepared from glyoxalic-monohydrate and urea by cyclization and condensatikon reactions in the presence of catalyst. The result indicated that the yield of allantoin was up to 60% when a composite acid composed of _p_-toluenesulfonic acid and phosphoric acid (PTSA-H_3PO_4) was used as the catalyst. The product was identified by elemental analysis, IR and melting point test. The purity of product dtermined by titration method was above 98%.