反応 #45731

反応方程式

ammonium chloride

6-Bromo-2-cyclopropyl-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile

2,3-difluorophenylboronic acid

tripotassium phosphate

→

compound

収率 53.0%

2-Cyclopropyl-6-(2,3-difluorophenyl)-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile

収率 53.0%

溶媒

ethyl acetate

1,4-dioxane

反応条件

後処理

1. 1
   温度After cooling to room temperature
2. 2
   抽出The aqueous layer was extracted twice with ethyl acetate
3. 3
   洗浄washed with saturated brine
4. 4
   乾燥dried over anhydrous sodium sulfate
5. 5
   その他The solvent was evaporated away
6. 6
   その他the resulting residue was purified by middle-pressure liquid chromatography (eluent, hexane:ethyl acetate=9:1)

実験手順

6-Bromo-2-cyclopropyl-7-fluoro-5-methyl-1,3-benzoxazole-4-carbonitrile (I-77) (190 mg, 0.64 mmol), 2,3-difluorophenylboronic acid (407 mg, 2.58 mmol) and tripotassium phosphate (274 mg, 1.29 mmol) were dissolved in 1,4-dioxane (6 ml), then at room temperature, tetrakis(triphenylphosphine)palladium(0) (149 mg, 0.13 mmol) was added. The suspension was stirred under nitrogen atmosphere at 95° C. for 86 hours. After 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 solvent was evaporated away, and the resulting residue was purified by middle-pressure liquid chromatography (eluent, hexane:ethyl acetate=9:1) to obtain the entitled compound (111 mg, 53%) as a white solid.

出典