Boron tribromide → 3-cyclopentyl-2-(3-fluoro-4-hydroxy-phenyl)-N-thiazol-2-yl-propionamide

Participants

Reaction Conditions

Reaction Steps

A solution of 3-cyclopentyl-2-(3-fluoro-4-methoxy-phenyl)-N-thiazol-2-yl-propionamide (prepared as in Example 118, 305.4 mg, 0.87 mmol) in methylene chloride (8.7 mL) at 25° C. was treated with a 1.0M solution of boron tribromide in methylene chloride (8.75 mL, 8.75 mmol). This solution was stirred at 25° C. for 5 h. At this time, the reaction was cooled to 0° C. and quenched by the dropwise addition of a dilute aqueous ammonium hydroxide solution. The resulting solution was stirred at 0° C. for 15 min. This mixture was then poured into water (50 mL) and extracted with ethyl acetate (3×30 mL). The combined organic layers were dried over sodium sulfate, filtered, and concentrated in vacuo. Flash chromatography (Merck Silica gel 60, 230-400 mesh, 50/50 hexanes/ethyl acetate) afforded 3-cyclopentyl-2-(3-fluoro-4-hydroxy-phenyl)-N-thiazol-2-yl-propionamide (212.7 mg, 72.5%) as a white solid: mp 199-201° C.: EI-HRMS m/e calcd for C17H19FN2O2S (M+) 334.1151 found 334.1152.

Provenance & Evidence