反应详情

600 mg of sodium hydride dispersion (55-60% in oil) were dissolved in 50 ml of abs. ethanol under argon. 3.68 g of 2-[[(3-methyl-4-nitro-2-pyridyl)methyl]thio]-5-(trifluoromethyl)benzimidazole were added thereto and the solution was left to stir at 70° for 1 hour. The solution was neutralized with glacial acetic acid and the mixture was then evaporated in a vacuum. The residue was treated with aqueous sodium bicarbonate solution and methylene chloride. The organic phase was separated and the aqueous phase was extracted several times with methylene chloride. The combined organic phases were dried and concentrated The residue was chromatographed on silica gel with methylene chloride/methanol (9:1), using the medium pressure flash chromatography method, pressure was produced with nitrogen gas. There was obtained 2-[[(4-ethoxy-3-methyl-2-pyridyl)methyl]thio]-5-(trifluoromethyl)benzimidazole. After recrystallization from ethyl acetate/ether the product melts at 173°-177°.

1. waitthe solution was left
2. customthe mixture was then evaporated in a vacuum
3. additionThe residue was treated with aqueous sodium bicarbonate solution and methylene chloride
4. customThe organic phase was separated
5. extractionthe aqueous phase was extracted several times with methylene chloride
6. customThe combined organic phases were dried
7. concentrationconcentrated The residue
8. customwas chromatographed on silica gel with methylene chloride/methanol (9:1)
9. custompressure was produced with nitrogen gas