噻虫嗪中间体3-甲基-4-硝基亚胺基四氢-1,3,5-噁二嗪的合成及液相色谱分析

Synthesis and LC Analysis of Thiamethoxam's Intermediate3-Methyl-4-nitroimino Tetrahydro-1,3,5-oxadiazine

对噻虫嗪重要中间体3-甲基-4-硝基亚胺基四氢-1,3,5-噁二嗪的合成工艺进行了研究,在80℃下,以乙酸溶液为溶剂,以磷酸为催化剂,2.5倍当量多聚甲醛,反应时间为12 h的条件下反应效果最佳,收率达到87%,含量98%以上。建立了液相色谱分析方法,可准确判定其反应终点,利于工业生产。

The synthesis process of 3 - methyl, 4 - nitro - imino - tetrahydro - 1,3,5 - oxadiazine ; a important intermediate of Thiamethoxam, was studied. The optimum conditions were determined： Acetic acid solution as the solvent, reaction temperature 80℃, phosphoric acid as a catalyst, 2.5 times paraformaldehyde, reaction time 12 h. Under the conditions, the yield was up to 87%, and the content was more than 98%. A liquid chromatography analysis method was established, that could accurately determine the end of the reaction, beneficially to industrial production.