The invention discloses a preparation method of 2-
mercaptobenzothiazole. The preparation method comprises the following steps of: preparing a
sulfur dissolving solution in advance; preparing materials, namely adding
aniline into a synthesis reactor, then adding the
sulfur dissolving solution, and finally adding
aniline and raising the temperature; performing a reaction for 2.5 hours to generate a 2-
mercaptobenzothiazole solution under the condition that the temperature is stabilized between 200 and 210 DEG C and the pressure is controlled between 80 and 81Mpa; performing exhausting; discharging materials, namely adopting an upper discharging mode, opening a steam valve, pressing out the 2-
mercaptobenzothiazole solution, discharging the materials from a
discharge pipe penetrating through the top of the reactor, and pressing the materials into a real-time stirring alkali dissolving tank in which caustic soda is introduced in advance; performing alkali
dissolution; performing changing; performing
neutralization; and treating resin. According to the preparation method, the 2-mercaptobenzothiazole is produced by adopting a high-pressure one-
step method, the
sulfur dissolving solution enters a reaction kettle to react with
aniline, and the 2-mercaptobenzothiazole is synthesized by one step under a
high pressure. The preparation method is simple and safe in production, good in product quality, and excellent in technical and economic index, and basically has no discharged waste, so that the preparation method is relatively wide in application.