4,6-二氯嘧啶清洁合成工艺  

Clean synthesis process of 4,6-dichloropyrimidine

作　　者：杨丰科[1] 董志强 张永富 牛鹏程 高巍伟 YANG Fengke;DONG Zhiqiang;ZHANG Yongfu;NIU Pengcheng;GAO Weiwei(College of Chemical Engineering,Qingdao University of Science&Technology,Qingdao 266042,Shandong,China)

机构地区：[1]青岛科技大学化工学院,山东青岛266042

出　　处：《精细化工》2021年第8期1711-1715,共5页Fine Chemicals

基　　金：山东省重点研究发展计划(特殊社会公益专项)(2017GSF17106);山东省自然科学青年基金(ZR2020QB168)。

摘　　要：报道了一种清洁合成4,6-二氯嘧啶(DCP)工艺。首先,由甲酰胺、丙二酸二甲酯和甲醇钠制备4,6-二羟基嘧啶(DHP)。当n(丙二酸二甲酯)∶n(甲酰胺)∶n(甲醇钠)=1∶4∶4,反应温度为60℃,反应时间2h时,DHP的收率可达90.4%。然后,DHP与POCl_(3)在60℃下反应2h获得DCP。此反应的最佳条件为:5-乙基-2-甲基吡啶为缚酸剂,质量分数45%的1,2-二氯乙烷作溶剂,n(DHP)∶n(POCl3)∶n(5-乙基-2-甲基吡啶)=1∶2.2∶1.8,DCP的收率高达94.6%。确定以氢氧化钙处理氯化废水的工艺,缚酸剂的回收率高达90%以上,磷酸钙与氯化钙能有效分离,成功解决DCP生产过程中的三废问题,实现了DCP清洁生产的目标。A clean process for the synthesis of 4,6-dichloropyrimidine(DCP)was reported.Firstly,4,6-dihydroxypyrimidine(DHP)was prepared from formamide,dimethyl malonate and sodium methoxide.Under the conditions of n[dimethyl malonate]∶n(formamide)∶n(sodium methoxide)=1∶4∶4,reaction temperature 60℃ and reaction time 2 h,the yield of DHP could reach 90.4%.Then,DCP was obtained by the reaction of DHP with POCl_(3) at 60℃ for 2 h.The optimum conditions for the synthesis of DCP were obtained as follow:5-ethyl-2-methylpyridine used as acid binding agent,mass fraction 45% 1,2-dichloroethane as solvent,n(DHP)∶n(POCl3)∶n(5-ethyl-2-methylpyridine)=1∶2.2∶1.8.Under these conditions,the yield of DCP was up to 94.6%.The process of treating chlorinated wastewater with calcium hydroxide was determined.The recovery rate of acid binding agent was over 90%,calcium phosphate and calcium chloride could be separated effectively,and the problem of three wastes in DCP production was solved successfully,and the goal of clean production of DCP was realized.

关 键 词：4 6-二羟基嘧啶 4 6-二氯嘧啶 缚酸剂 废水处理 精细化工中间体 

分 类 号：TQ254.1[化学工程—有机化工]