杀菌剂5-氯-2-甲基-3-异噻唑酮的合成

Synthesis of Bactericide 5-Chloro-2-methyl-3-isothiazoleone

通过三步反应合成5-氯-2-甲基-3-异噻唑酮。a)丙烯酸甲酯、多硫化钠、亚硫酸钠在O℃～5℃反应5h得二硫代丙烯酸甲酯,收率90％;b)二硫代丙烯酸甲酯、甲苯、甲醇混合液在15℃～20℃下滴加甲胺反应10h得N,N-二甲基-二硫代丙烯酸胺,收率100％;c)N,N-二甲基-二硫代丙烯酰胺、二氯乙烷混合液在25℃滴加二氯砜升温反应15h,经过后处理得5-氯-2-甲基-3-异噻唑酮。

This experiment synthesized 5-chloro-2-methyl-3-isothiazoleone was three reaction steps. a) methyl acrylate ,sodium polysulfide and sodium sulphite reacted at 0 ℃~5℃ for 5 hours to obtain methyl dithioacrylate ,yield 90 %. b) methylic acid was added dropwise into the mixtrue of methyl dithioacrylate,toluene and methanol at 15 ℃~20℃ and reacted for 10 hours to obtain N.N-dimethyl-dithioacrylic amide, yield 100 %. c) dichlorosulfore was added dropwise into the mixture of N.N-dimethyl-dithioacrylic amide and diamino ethane,and reacted with heating for 15 hours,then after post-treatment to obtain 5-chloro-2-methyl-3-isothiazoleone.