反应详情

To a suspension of 2-methylimidazo[4,5-b]pyridine-5-carbonitrile (200 mg) in N,N-dimethylformamide (2 ml) was added sodium hydride (70% in mineral oil, 55 mg) under ice-cooling, and the mixture was stirred for 30 min. To this reaction mixture was added 4-bromo-2-chlorobenzyl methanesulfonate (450 mg), and the mixture was stirred for 2 hr at room temperature. The reaction mixture was poured into water and the product was extracted three times with ethyl acetate. The organic layers were combined and washed successively with water and saturated brine, dried over anhydrous magnesium sulfate and the solvent was evaporated. The residue was subjected to silica gel column chromatography (dichloromethane/ethyl acetate=5/1) to give two isomers, 3-(4-bromo-2-chlorobenzyl)-2-methyl-3H-imidazo[4,5-b]pyridine-5-carbonitrile (Rf 0.4, 233 mg) and 1-(4-bromo-2-chlorobenzyl)-2-methyl-1H-imidazo[4,5-b]pyridine-5-carbonitrile (Rf 0.1, 163 mg) as a white powder and a pale-yellow powder.

1. temperaturecooling
2. stirringthe mixture was stirred for 2 hr at room temperature
3. extractionthe product was extracted three times with ethyl acetate
4. washwashed successively with water and saturated brine
5. dry with materialdried over anhydrous magnesium sulfate
6. customthe solvent was evaporated