反应详情

69.9 g (0.5 mol) of 2,6-difluorobenzonitrile and 237 g (1.2 mol) of 6-normal sodium hydroxide solution are initially introduced in 200 ml of benzyl alcohol. 221 g (1.95 mol) of 30% hydrogen peroxide solution are added dropwise to this mixture within the space of 30 min, the temperature rising from 20° C., at the beginning of the metering-in, to 50° C., and then being maintained at this value. After 5 h (complete transformation to 2-benzyloxy-6-fluorobenzamide can be demonstrated by GC), the mixture is cooled and supplemented with 200 g of water and 60 g (1.5 mol) of sodium hydroxide. Chlorine is passed in (8-10 l/h) at 30° C. for 2 h, with the reaction being monitored by gas chromatography and terminated once the amide has disappeared. The phases are separated, 180 g of methanol are added to the organic phase, and further processing is carried out as indicated in Example 8. 32.4 g (0.255 mol, 51%) of 2-amino-3-fluorophenol are obtained as a brown-black powder.

1. customrising from 20° C., at the beginning
2. customto 50° C.
3. temperaturebeing maintained at this value
4. temperaturethe mixture is cooled
5. customterminated once the amide
6. customThe phases are separated
7. addition180 g of methanol are added to the organic phase, and further processing