反应详情

In 30 ml of methanol was suspended 3.00 g of methyl 2-(2,4-difluorophenylamino)-5-fluoro-6-hydroxynicotinate, and 16.1 ml of 2N aqueous sodium hydroxide solution was added thereto at room temperature, after which the resulting mixture was subjected to reaction under reflux for 4 hours. Subsequently, the reaction mixture was added to a mixture of 60 ml of ethyl acetate and 60 ml of water, and the aqueous layer was separated. The aqueous layer was adjusted to pH 1.0 with 6N hydrochloric acid, and the crystals thus deposited were collected by filtration, washed successively with 15 ml of water and 25 ml of isopropyl alcohol to obtain 2.68 g (yield 93.7%) of 2-(2,4-difluorophenylamino)-5-fluoro-6-hydroxynicotinic acid having a melting point of 213°-216° C.

1. additionwas added
2. customat room temperature, after which the resulting mixture was subjected to reaction
3. temperatureunder reflux for 4 hours
4. customthe aqueous layer was separated
5. filtrationthe crystals thus deposited were collected by filtration
6. washwashed successively with 15 ml of water and 25 ml of isopropyl alcohol