Hydrochloric Acid → 6-Bromo-5,8-dimethylthiochroman-4-ol

Participants

Reaction Steps

100 ml of methanol and 30 ml of dichloromethane were added to 10 g (36.9 mmol) of 5,8-dimehyl-6-bromothiochroman-4-one. While the mixture was maintained at a temperature not exceeding 0° C. with a sodium chloride aqueous solution and an ice bath, 0.70 g (18.4 mmol) of sodium borohydride as a reducing agent was gradually added. The mixture was allowed to react at room temperature for 3 hours, and then the reaction mixture was poured into a 5% hydrochloric acid aqueous solution and extracted with dichloromethane. The resultant dichloromethane layer was dried over anhydrous sodium sulfate and concentrated to give 9.2 g (yield 91%) of 5,8-dimethyl-4-hydroxy-6-bromothiochroman (corresponding to compound of the formula (VI)).

Provenance & Evidence