Synthesis
127 mg (0.40 mmol) of 4,4'-dichloro-2,2'-dithiodianiline and 11.2 mg (0.2 mmol) of NaHS were added to the reaction flask, followed by the addition of 2.5 mL of H2O as reaction solvent. Subsequently, 97 μL (1.6 mmol) of carbon disulfide was injected and the reaction mixture was stirred at 80 °C for 4 hours. The progress of the reaction was monitored by thin-layer chromatography (TLC) and after confirming the complete reaction of the disulfide feedstock, the reaction mixture was cooled to room temperature. The reaction mixture was extracted with ethyl acetate, the organic phases were combined and the solvent was removed under reduced pressure by rotary evaporator to give the crude product. The crude product was purified by column chromatography (200-300 mesh silica gel) using a gradient elution with dichloromethane as eluent. Finally, 122 mg of 6-chloro-2-mercaptobenzothiazole was obtained as a white powder with purity greater than 99%, isolated yield of 75.6%, and melting point of 239-241°C. The product was purified by column chromatography (200-300 mesh silica gel) using dichloromethane as eluent.
