反应详情

温度

-78 °C

4-Bromo-2-methyl-1H-benzimidazole (500 mg, 2.37 mmol) was dissolved in THF (8 mL) and cooled to −78° C. n-Butyllithium (2.3 mL, 2.5 M in hexanes, 5.7 mmol) was added dropwise and the reaction was stirred at −78° C. for 30 min. Trifluoroacetic acid ethyl ester (339 μL, 2.8 mmol) was added and the reaction was stirred at 0° C. for 1 h. The reaction was quenched with HCl (2 N, 4 mL), then extracted with water and EtOAc, washed with brine, dried over Na2SO4, filtered, and concentrated in vacuo. Purification by normal phase silica gel column chromatography (CH2Cl2/MeOH/NH4OH) provided 2,2,2-trifluoro-1-(2-methyl-1H-benzoimidazol-4-yl)-ethanone.

1. additionwas added dropwise
2. stirringthe reaction was stirred at 0° C. for 1 h
3. customThe reaction was quenched with HCl (2 N, 4 mL)
4. extractionextracted with water and EtOAc
5. washwashed with brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated in vacuo
9. customPurification by normal phase silica gel column chromatography (CH2Cl2/MeOH/NH4OH)