Process for the preparation of 2-mercaptobenzothiazole

摘要

In a process for the preparation of 2-mercaptobenzothiazole from aniline, sulfur and carbon disulfide under pressure and for separation of the 2-mercaptobenzothiazole from the crude reaction product by cooling and recycling the desirable intermediates and by-products into the reactor together with aniline, sulfur and carbon disulfide, the reaction is carried out using a residence time in the reactor of at least one hour to a time before the 2-mercaptobenzothiazole product thus-formed begins to decompose into undesirable intermediate products. A maximum hydrogen sulfide pressure is maintained on quenching to a temperature ranging between 220 and 280 DEG C. by mixing the crude reaction product with carbon disulfide at a temperature sufficient to obtain a homogeneous quenched mixture. The hydrogen sulfide is removed completely only after crystallization of the 2-mercaptobenzothiazole.