反应详情

23.2 g (0.1 mole) of 5-(2,4-dichloro-5-fluoro-phenyl)-isoxazole are added in portions to a solution of 2.3 g (0.1 g atom) of sodium in 100 ml of absolute ethanol in the course of about 30 minutes while cooling with ice and stirring. The mixture is then stirred at room temperature for 1 hour, the alcohol is distilled off in vacuo, the residue is dissolved in about 1 litre of warm water, the solution is extracted twice with methylene chloride, the aqueous phase is acidified to pH=4 with 10 per cent strength hydrochloric acid (~38 ml) and the precipitate is filtered off cold with suction and dried in vacuo at 50° C. 21.7 g (93%) of 2,4-dichloro-5-fluoro-benzoylacetonitrile of melting point 98°-99° C. are obtained.

1. temperaturewhile cooling with ice
2. stirringThe mixture is then stirred at room temperature for 1 hour
3. distillationthe alcohol is distilled off in vacuo
4. dissolutionthe residue is dissolved in about 1 litre of warm water
5. extractionthe solution is extracted twice with methylene chloride
6. filtrationthe precipitate is filtered off cold with suction
7. customdried in vacuo at 50° C