Acetic Anhydride → HCID 68283126, compound

Participants

Reaction Steps

To a solution of the compound obtained in Step B (390 mg, 0.95 mmol) in isopropanol (10 mL) at ambient temperature there is added sodium borohydride (179 mg, 4.7 mmol). The mixture is stirred for 3 hours under reflux, and then a solution of sodium hydroxide (76 mg, 1.9 mmol) in water (2.0 mL) is added dropwise. The mixture is maintained under reflux for 30 minutes, and then acetone (1.5 mL) is added. After 10 minutes, the mixture is cooled to ambient temperature before being concentrated under reduced pressure. The oil thereby obtained is dissolved in dichloromethane (10 mL). Dimethylaminopyridine (255 mg, 2.1 mmol) is then added, followed by acetic anhydride (200 μL, 2.1 mmol) dropwise. The solution is stirred at ambient temperature for 1 hour and then water is added. A few drops of hydrochloric acid (1N) are also added to obtain an acid pH. The aqueous phase is extracted with dichloromethane and the organic phases are washed with saturated NaCl solution, dried over magnesium sulphate, filtered and evaporated. The title compound is obtained after purification by flash column chromatography (ethyl acetate-petroleum ether: 90-10, then ethyl acetate-methanol: 90-10) in the form of an oil in a yield of 64%.

Provenance & Evidence