Ammonium Chloride → 4-cyano-7-fluoro-6-(3-fluorophenyl)-N,N,5-trimethyl-1,3-benzoxazole-2-carboxamide

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Reaction Conditions

Reaction Steps

6-Bromo-4-cyano-7-fluoro-N,N,5-trimethyl-1,3-benzoxazole-2-carboxamide (I-127) (200 mg, 0.61 mmol), 3-fluorophenylboronic acid (343 mg, 2.45 mmol) and tripotassium phosphate (261 mg, 1.23 mmol) were suspended in 1,4-dioxane (6 ml), and at room temperature, tetrakis(triphenylphosphine)palladium(0) (142 mg, 0.12 mmol) was added. The suspension was stirred under nitrogen atmosphere at 95° C. for 62 hours, followed by cooling to room temperature. The solution was fractionated with ethyl acetate and aqueous saturated ammonium chloride solution. The aqueous layer was extracted twice with ethyl acetate. The organic layers were combined, washed with saturated brine, and dried over anhydrous sodium sulfate. The insoluble matter was separated by filtration, the solvent was evaporated away, and the resulting residue was purified by middle-pressure liquid chromatography (eluent, hexane:ethyl acetate=5:2) to obtain the entitled compound (76 mg, 36%) as a white solid.

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