Boron tribromide → 4-[4-(4-Ethyl-5-fluoro-2-hydroxyphenoxy)-3-fluorobenzoyl]-1-methylpiperazin-2-one

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Reaction Steps

A commercial solution of boron tribromide (1N in DCM, 1.33 mL, 1.32 mmol) was added to a solution of 4-[4-(4-ethyl-5-fluoro-2-methoxyphenoxy)-3-fluorobenzoyl]-1-methylpiperazin-2-one (which may be prepared in accordance with the experimental described in Example 5, step 2; 200 mg, 0.49 mmol) in dichloromethane (1.6 mL) placed under argon at −30° C. The reaction mixture was stirred at room temperature overnight and diluted by addition of dichloromethane (30 mL) and a saturated solution of ammonium chloride (30 mL). After separation, the aqueous layer was extracted with dichloromethane (2×30 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/methanol (95:5) as eluent. The title product was obtained as a yellow solid (135 mg, 70%).

Provenance & Evidence