Ammonium Chloride → 2-Cyclopropyl-7-fluoro-6-(3-fluorophenyl)-5-methyl-1,3-benzoxazole-4-carbonitrile

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Reaction Conditions

Reaction Steps

6-Bromo-2-cyclopropyl-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile (I-77) (200 mg, 0.68 mmol), 3-fluorophenylboronic acid (380 mg, 2.71 mmol) and tripotassium phosphate (288 mg, 1.36 mmol) were dissolved in 1,4-dioxane (8 ml), then at room temperature, tetrakis(triphenylphosphine)palladium(0) (157 mg, 0.14 mmol) was added. The solution was stirred under nitrogen atmosphere at 95° C. for 17 hours. After cooling to room temperature, the reaction liquid was fractionated with ethyl acetate and aqueous saturated ammonium chloride solution. The aqueous layer was further 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=8:1) to obtain the entitled compound (151 mg, 72%) as a white solid.

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