反应详情

温度

-30 °C

Under an atmosphere of argon, 850 ml of THF solution of 2,4-difluorophenylmagnesium bromide prepared from 202.6 g (1.05 mol) of 2,4-difluorobromobenzene and 26.7 g (1.1 mol) of magnesium turnings was added dropwise at -30° C. to 1.7 l of THF solution of 174 g (1.00 mol) of 1,3-diacetoxyacetone which was previously cooled to -30° C. After the resulting liquid was stirred at -60° C. for 2 hours, a temperature thereof was gradually raised to room temperature. Then, to the reaction mixture was added 1 l of 1.2 N aqueous solution of hydrochloric acid at 5° C. or below, and an aqueous layer was extracted twice with 1 l of ethyl acetate. The organic layer was washed with saturated aqueous solution of sodium chloride, dried and concentrated under reduced pressure to give 302 g of crude oil. The obtained oil was purified by means of column chromatography on silica gel (hexane:ethyl acetate=1:1) to give 125 g of the desired compound. The compound was recrystallized from toluene/hexane

1. temperaturea temperature thereof was gradually raised to room temperature
2. extractionan aqueous layer was extracted twice with 1 l of ethyl acetate
3. washThe organic layer was washed with saturated aqueous solution of sodium chloride
4. customdried
5. concentrationconcentrated under reduced pressure
6. customto give 302 g of crude oil
7. customThe obtained oil was purified by means of column chromatography on silica gel (hexane:ethyl acetate=1:1)