Water → 4-[4-(4-Ethyl-5-fluoro-2-hydroxyphenoxy)-3-fluorobenzoyl]piperazin-2-one

Participants

Reaction Steps

A commercial solution of boron tribromide (1N in DCM, 3.5 mL, 3.46 mmol) was added to a solution of 4-[4-(4-ethyl-5-fluoro-2-methoxyphenoxy)-3-fluorobenzoy]piperazin-2-one (which may be prepared in accordance with the experimental described in Example 5, step 1; 500 mg, 1.28 mmol) in dichloromethane (4.3 mL) placed under argon at −30° C. The reaction mixture was stirred at room temperature for 36 hours then diluted by addition of dichloromethane (20 mL) and water (20 mL). After separation, the aqueous layer was extracted with dichloromethane (2×20 mL). The combined organic phases were dried over sodium sulfate, filtered and concentrated under vacuum. The residue was purified by chromatography on silica gel, using dichloromethane/acetone (80:20) as eluent. The title product was obtained as a beige solid (440 mg, 92%).

Provenance & Evidence