Improved method for synthesizing 2-mercaptobenzothiazole derivative

The invention discloses an improved method for synthesizing a 2-mercaptobenzothiazole derivative. The method comprises the following steps of: putting relatively simple raw materials consisting of a phenylamine derivative, carbon disulfide and sulphur in a reaction kettle; introducing N2 till the reaction pressure is kept in a range of 6-15 MPa; raising the temperature to 200-260 DEG C; reacting for 2-5 h; dissolving the product by using alkali; filtering and removing side-effect impurities; and acidizing and separating the product, the content of which is above 99%. The reaction yield can be increased to 90-100% by optimizing a reaction condition. The method disclosed by the invention has the advantages that: the cost of reaction raw materials is saved; the reaction time is shortened; furthermore, the reaction purity and the yield are increased; and the method can be popularized for large-scale industrial production.