463-58-1

7732-36-7

40925-65-3

A magnetic stirrer was added to a 12 mL stainless steel autoclave, and 0.5 mmol of [2-(2-amino-5-methoxy-phenyl)disulfanyl-4-methoxy-phenyl]amine, 0.25 mmol of sodium hydrosulfide, and 1 mL of N,N-dimethylformamide (DMF) were sequentially added to the reactor vessel, which was sealed. The reactor was charged with 0.5 MPa of carbonyl sulfide (COS) and reacted under stirring for 1.5 hours. After the reaction was completed, the gas in the reactor was slowly released. The reactor was opened and the reaction mixture was transferred to a 50 mL conical flask. Extraction was carried out with ethyl acetate and the organic phase was washed with saturated aqueous sodium chloride solution. After drying by anhydrous magnesium sulfate, the desiccant was removed by filtration and the filtrate was concentrated under reduced pressure to give the crude product. Purification was carried out by silica gel column chromatography (200-300 mesh) using a solvent mixture of dichloromethane and ethyl acetate as eluent. Fractions containing the target product 6-methoxy-2(3H)-benzothiazolone were collected and the solvent was evaporated under reduced pressure to give the pure product.