High-purity 2-mercaptobenzothiazole (2-MBT) is prepared from crude 2-MBT by aniline method under high pressure by solvent crystallization and deep impurity removal. For the first step of toluene purification, the semi-finished 2-MBT with excellent purity and yield can be obtained when the temperature of toluene solution reaches 100 oC and the content of toluene is about 1.5 times of that of crude 2-MBT. For the second step of deep purification, the by-products of semi-finished 2-MBT could be further removed by Na2SO3 when the mass ratio of water, the 2-MBT and Na2SO3 is 2: 1: 0.12 and the reaction condition is under 100 oC for 0.75 h. As a result, the purity and yield of 2-MBT can reach 99.9% and 97.3%, respectively. The preparation of high-purity 2-MBT would further optimize the market demand and meet the quality standard requirements for the development of other pharmaceutical intermediates or fine chemicals. This strategy solves the current problem of purification 2-MBT, and develops a new process technology route for the production of high-purity 2-MBT.

中文翻译：

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两步纯化高纯度2-巯基苯并噻唑

由2-MBT粗品通过苯胺法在高压下通过溶剂结晶和深层杂质去除制得高纯度的2-巯基苯并噻唑（2-MBT）。对于甲苯纯化的第一步，当甲苯溶液的温度达到100 o C且甲苯含量约为2-MBT粗品的1.5倍时，可获得纯度和收率极高的2-MBT半成品。对于深度纯化的第二步，当水，2-MBT和Na 2 SO 3的质量比为2：1：0.12时，Na 2 SO 3可以进一步去除半成品2-MBT的副产物。和反应条件下100 öC保持0.75小时。结果，2-MBT的纯度和产率可以分别达到99.9％和97.3％。高纯度2-MBT的制备将进一步优化市场需求，并满足开发其他医药中间体或精细化学品的质量标准要求。该策略解决了目前纯化2-MBT的问题，并为生产高纯度2-MBT开发了一条新的工艺技术路线。