反应详情

温度

140 °C

2700 g of 3,5,6-trifluoro-4-hydroxyphthalic acid and 6 liters of water were placed in an autoclave, and the mixture was heated at 140° C for 3 hours in an atmosphere of nitrogen. At the end of this time, the reaction mixture was cooled to room temperature and concentrated by evaporation under reduced pressure, to precipitate crystals, which were collected by filtration, washed with chloroform and dried to give 1623 g of 2,4,5-trifluoro-3-hydroxybenzoic acid [(XXIII), X =X'=F] as a colorless powder, melting at 144°-146° C.

1. temperatureAt the end of this time, the reaction mixture was cooled to room temperature
2. concentrationconcentrated by evaporation under reduced pressure
3. customto precipitate crystals, which
4. filtrationwere collected by filtration
5. washwashed with chloroform
6. customdried