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.
作者
杨丰科
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)
出处
《精细化工》
EI
CAS
CSCD
北大核心
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)。
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
4,6-dihydroxypyrimidine
4,6-dichloropyrimidine
acid binding agent
wastewater treatment
fine chemical intermediates
