反应详情

8.8 g (20.7 mmol ) 5,5-dimethyl-3-(3-nitro-4-trifluormethoxy-phenyl)-1-pyridin-4-ylmethyl-imidazolidine-2,4-dione were dissolved in 200 ml semi-conc. hydrochloric acid. 30 g zinc dust were added in portions and the resulting mixture was refluxed for 1 h, cooled to RT, diluted with 100 ml water and extracted with ethyl acetate. The aqueous phase was made alkaline with saturated sodium hydroxide solution and extracted with methylene chloride. Separating zinc salts were removed by filtration over cellite. Evaporation of the combined organic phases and flash chromoatography of the residue (Silica gel, methylene chloride:methanol=95:5) gave 4.7 g of the desired product.

1. temperaturethe resulting mixture was refluxed for 1 h
2. extractionextracted with ethyl acetate
3. extractionextracted with methylene chloride
4. customSeparating zinc salts were removed by filtration over cellite
5. customEvaporation of the combined organic phases and flash chromoatography of the residue (Silica gel, methylene chloride:methanol=95:5)