反应详情

226 ml (0.226 mole) of a 1N aqueous solution of sodium hydroxide were added to a suspension of 46.4 g (0.226 mole) of 3-methoxy-2,4,5-trifluorobenzamide (XXV) [prepared as described in Step (E5) above] in 900 ml of water, and the mixture was heated under reflux with stirring for 2 hours. At the end of this time, the reaction mixture was cooled to room temperature and then shaken with ethyl acetate to remove unreacted material. The aqueous layer was separated and acidified with hydrochloric acid to precipitate a crystalline substance, which was extracted with ethyl acetate. The extract was washed with water and dried, and the solvent was removed by evaporation under reduced pressure to afford 37.1 g of 3-methoxy-2,4,5-trifluorobenzoic acid (XXVI) as colorless needles having the same properties as the product of Preparation 1.

1. temperaturethe mixture was heated
2. temperatureunder reflux
3. customto remove unreacted material
4. customThe aqueous layer was separated
5. customto precipitate a crystalline substance, which
6. extractionwas extracted with ethyl acetate
7. washThe extract was washed with water
8. customdried
9. customthe solvent was removed by evaporation under reduced pressure