反应详情

温度

25 °C

After 44.7 g (0.131 mol) of the ammonium salt of 4-hydroxy-4-(3-indolylmethyl)-2-hydroxyiminoglutaric acid was dissolved in 500 ml of water at 25° C., the resulting aqueous solution was adjusted to pH 2 using 25.5 g of 36% hydrochloric acid. The acidic solution was extracted in 1300 ml of ethyl acetate, and the resulting ethyl acetate solution was rinsed with 200 ml of aqueous saturated sodium chloride solution. 500 ml of an aqueous sodium carbonate solution (13.9 g (0.131 mole) of sodium carbonate) was added to the resulting ethyl acetate solution for agitation, to separate the aqueous alkali solution from ethyl acetate. 23.1 g of 36% hydrochloric acid was added to the resulting aqueous alkali solution, to adjust the solution to pH 2. 6.99 g (57.6 mmol) of(R)-(+)-1-phenylethylamine was added dropwise to the resulting aqueous acidic solution and the solution stirred at 25° C. for one hour. The resulting crystal was filtered and dried under reduced pressure, to obtain 21.8 g (47.8 mmol) of the (R)-(+)-1-phenylethylamine salt of (4S)-4-hydroxy-4-(3-indolylmethyl)-2-hydroxyiminoglutaric acid. (Yield, 72.7%; optical purity, 87.4%.)

1. extractionThe acidic solution was extracted in 1300 ml of ethyl acetate
2. washthe resulting ethyl acetate solution was rinsed with 200 ml of aqueous saturated sodium chloride solution
3. customto separate the aqueous alkali solution from ethyl acetate
4. addition23.1 g of 36% hydrochloric acid was added to the resulting aqueous alkali solution
5. filtrationThe resulting crystal was filtered
6. customdried under reduced pressure