反应详情

To a solution of sodium bicarbonate (5.56 g.) in water (200 ml.) was added and dissolved with stirring 3-hydroxyphenylglyoxylic acid (11 g.) under cooling. On the other hand, hydroxylamine hydrochloride (4.60 g.) was added and dissolved into a solution of sodium bicarbonate (5.56 g.) in water (70 ml.) with stirring at room temperature. Thus obtained solution was added with stirring to the above obtained solution under cooling. The mixture was stirred for 20 hours at room temperature and was subjected for salting-out treatment. Then, the reaction solution was acidified with hydrochloric acid and was extracted with ethyl acetate. The extract was washed with saturated aqueous solution of sodium chloride and dried. After solvent was distilled off, the residue was crystallized from benzene. The crystals were collected by filtration to obtain 2-hydroxyimino-2-(3-hydroxyphenyl)acetic acid (syn isomer) (6g.).

1. temperatureunder cooling
2. additionThus obtained solution was added
3. stirringwith stirring to the above obtained solution
4. temperatureunder cooling
5. stirringThe mixture was stirred for 20 hours at room temperature
6. extractionwas extracted with ethyl acetate
7. washThe extract was washed with saturated aqueous solution of sodium chloride
8. customdried
9. distillationAfter solvent was distilled off
10. customthe residue was crystallized from benzene
11. filtrationThe crystals were collected by filtration