还原桃红R中间体2-羟基-4-甲基-6-氯苯并[1,2,3]二噻唑的合成研究

Study on Synthesis of Vat Pink R Intermediate 6-Chloro-4-methyl-1,3,2-benzothiazathiolium hydroxide

以邻甲苯胺为原料,与盐酸成盐制得邻甲苯胺盐酸盐,其再经硫化得2-氯-4-甲基-6-氯苯并[1,2,3]二噻唑,最后经水解合成还原桃红R中间体2-羟基-4-甲基-6-氯苯并[1,2,3]二噻唑。笔者对成盐反应物质的量及硫化反应的物物质的量比、反应温度、反应时间及溶剂用量等因素进行了探讨,得出优化反应条件为:n(邻甲苯胺)∶n(氯化氢)=1∶1.13,成盐收率可达99.8%;邻甲苯胺盐与一氯化硫硫化,n(邻甲苯胺盐)∶n(一氯化硫)=1∶3.75,硫化反应温度60±2℃,保温反应时间4 h,溶剂质量与邻甲苯胺盐物质的量的比为182.1 g/mol,此时目标产物的收率可达95.5%。产物结构经IR、LC/MS与1H NMR确证。

6-Chloro-4-methyl-1,3,2-benzothiazathiolium hydroxide,a key intermediate for vat pink R,was synthesized via salification,sulfurization and hydrolyzation from o-toluidine as the start material.Based on the research results for the molar ratio of salification,molar ratio,reaction temperature,reaction time and solvent consumption of sulfurization,the optimum reaction conditions were obtained as following:the yield of salification was 99.8% while the reaction molar ratio of o-toluidine to hydrochloride was 1∶1....