反应详情

温度

30 °C

27.3 g (0.10 mol) of 3-(4-chloro-2-fluoro-5-methoxyphenyl)-1-methyl-imidazolidine-2,4-dione are dissolved in 200 ml of methanol, and 5.7 g (0.15 mol) of sodium borohydride are added in portions at a rate such that the temperature increases to 30°-35° C. When the addition is complete, the mixture is stirred for a further 1 hour at 30° C. The mixture is poured into 500 ml of ice-water, and the precipitate which deposits is filtered off under suction. After drying, 25.2 g (92% of theory) of 3-(4-chloro-2-fluoro-5-methoxyphenyl)-4-hydroxy-1-methylimidazolidin-2-one are obtained in the form of colorless crystals having the melting point 138°-140° C.

1. temperatureincreases to 30°-35° C
2. additionWhen the addition
3. filtrationthe precipitate which deposits is filtered off under suction
4. customAfter drying