Boron tribromide → HCID 25183798, compound

Participants

Reaction Conditions

Reaction Steps

To a cooled (0° C.) solution of 32 (300.0 mg; 0.78 mmol) in dichloromethane (3.9 mL) was added boron tribromide (0.52 mL; 5.47 mL) dropwise. The reaction mixture was stirred at 0° C. then allowed to gradually warm to room temperature. After stirring 4 hours at room temperature, the reaction mixture was cooled to 0° C. again, slowly quenched with methanol; and then diluted with chloroform. The organic layer was washed with water, dried over magnesium sulfate, filtered and concentrated under reduced pressure. The crude residue was re-dissolved in diethyl ether and washed with aqueous sodium hydroxide (2N). The aqueous layer was acidified to pH˜2 with concentrated hydrochloric acid and extracted with chloroform (3×). The organic extracts were combined, dried over magnesium sulfate, filtered, and concentrated under reduced pressure. The crude residue was purified by automated silica gel column chromatography (Biotage®) eluting with ethyl acetate/hexanes and then by preparative HPLC to afford the title compound as a white solid (101 mg).

Provenance & Evidence