杀菌剂N-正丁基-1,2-苯并异噻唑啉-3-酮的合成工艺研究

Process research on the synthesis of N-butyl-1,2-benzoisothiazoline-3-one

研究了以邻甲硫基苯甲酸为原料,经酰氯化、酰胺化以及关环等反应合成杀菌剂N-正丁基-1,2-苯并异噻唑啉-3-酮(BBIT)的新工艺。探讨了缚酸剂、关环试剂以及温度等对反应的影响。确定的最优条件为:酰胺化反应以氢氧化钠作为缚酸剂,反应温度为10±2℃;关环反应以氯气作为关环试剂,反应温度为50±2℃。在此条件下,BBIT的总收率为90%,含量大于99%。该工艺各步中间体无需纯化,操作简单,有利于工业化生产。

A novel process for the synthesis of N-butyl-1,2-benzoisothiazoline-3-one(BBIT)was developed by using o-methyl thiobenzoic acid as starting material via acyl chlorination,amidation,and cyclization.The effects of acid acceptor,cyclization reagent and temperature were discussed.The optimum conditions were as follows:sodium hydroxide as acid acceptor for amidation at 10±2℃,Chlorine as cyclization reagent at 50±2℃.The total yield was 90%,and purity≥99%.The unit process was simple and fit for industrialization while all intermediates were used directly without purification.