2-氯烟酸合成新工艺  

A new process for the preparation of 2-chloronicotinic acid

作　　者：谢龙观[1] 吕培[1] 孙立冬[1] 徐效华[1] 

机构地区：[1]南开大学元素有机化学研究所,天津300071

出　　处：《农药》2013年第2期90-91,共2页Agrochemicals

摘　　要：[目的]为了在可控反应条件下,从易得廉价材料作为起始原料,高产率制备2-氯烟酸的市场迫切需要,报道了一条制备2-氯烟酸新工艺。[方法]以固体光气、DMF为起始原料,经与乙烯基正丁醚反应,得到铵基化合物C,进一步与氰基乙酸乙酯缩合得到2-氰基-5-二甲胺基-2,4-二烯-戊酸乙酯(D),通HCl气关环连续操作一步得到2-氯烟酸乙酯。该方法突出优点原位产生分步中间体可一锅反应。[结果]在连续操作"一锅"以68%总产率得到2-氯烟酸。[结论]新2-氯烟酸制备工艺反应条件温和、高产率、成本低廉,是一条适合工业化生产新工艺。[Aims] In order to an urgent need for a process which allows the preparation of 2-chloropyridine 3-carboxylic acids or their esters in high yield from cheap starting materials and under easily controllable reaction conditions. A new technical process has been reported for the preparation of 2-chloronicotinic acid. [Methods] The reaction of a vinyl etheris with Bis（trichloromethy）carbonate（triphosgene） in DMF yields an ammonium compound C. Then a cyanoacetic acid ester are added to obtain intermediate D, which may then be cyclised to give the desired 2-chloropyridine 3-carboxylic acid esters in presence of HC1 gas, it is especially advantageous to generate the intermediates in situ and to react them subsequently in one-pot reaction. [Results] 2-Chloronicotinic acid was obtained subsequently in a one-pot in 68% total yields. [Conclusions] A new process for the preparation of 2-chloronicotinic acid was developed in high yields under mild reaction conditions, which be suitable for technical scale production.

关 键 词：2-氯烟酸 合成 连续一锅法 

分 类 号：TQ455.4[化学工程—农药化工]