Synthesis
There are few reported methods for the synthesis of 2-mercapto-6-nitrobenzothiazole. 2-Mercapto-6-nitrobenzothiazole can be prepared by reacting 2-chloro-6-nitrobenzothiazole with carbon disulfide; or by the nitration of 2-mercaptobenzothiazole. The synthetic reaction formula for 2-mercapto-6-nitrobenzothiazole is shown in the figure below:
Experimental Procedure:
Add 2-chloro-6-nitrobenzothiazole, carbon disulfide, and an appropriate amount of adsorbent as a catalyst to a high-pressure reactor. Seal the reactor and heat it with stirring, controlling the reaction temperature within the set range.
After the reaction is complete, the mixture is cooled, and the hydrogen sulfide gas produced is absorbed with a 30% sodium hydroxide solution. The solid residue in the reactor is the crude product, 2-mercapto-6-nitrobenzothiazole. The crude 2-mercapto-6-nitrobenzothiazole is then purified to obtain the final product. The purification process mainly includes the following steps: dissolving in sodium hydroxide solution, filtration, forced-air oxidation, filtration, sulfuric acid acidification, filtration, washing, and vacuum drying.
