反应详情

温度

50 °C

To a suspension of 1.75 g of 5,5-dimethyl-3-{3-nitro-4-[(trifluoromethyl)thio]phenyl}imidazolidine-2,4-dione obtained in stage b) below in 60 mL of concentrated hydrochloric acid are added, portionwise, 7.5 g of zinc powder. The reaction mixture is heated at 50° C. for 8 hours and then cooled to room temperature and poured into a mixture of 100 mL of ethyl acetate and 20 mL of water. 5N sodium hydroxide solution is then added to pH 8 and the solid formed is then filtered off through Celite and washed with ethyl acetate. The phases are separated, the aqueous phase is washed with ethyl acetate and the combined organic phases are dried over magnesium sulphate, filtered and concentrated under reduced pressure. The residue is purified by chromatography on a column of silica, eluting with a mixture of dichloromethane and methanol (95/5 by volume) to give 400 mg of 3-{3-amino-4-[(trifluoromethyl)thio]phenyl}-5,5-dimethylimidazolidine-2,4-dione, the characteristics of which are as follows:

1. additionare added
2. temperaturecooled to room temperature
3. customthe solid formed
4. filtrationis then filtered off through Celite
5. washwashed with ethyl acetate
6. customThe phases are separated
7. washthe aqueous phase is washed with ethyl acetate
8. dry with materialthe combined organic phases are dried over magnesium sulphate
9. filtrationfiltered
10. concentrationconcentrated under reduced pressure
11. customThe residue is purified by chromatography on a column of silica
12. washeluting with a mixture of dichloromethane and methanol (95/5 by volume)