反应详情

6.8 Grams of 2-(4-chlorobenzoylamino)-3-(indol-3-yl)propionic acid prepared in Reference Example 6 was suspended in 8 g of dimethyl sulfoxide, then 17 g of concentrated hydrochloric acid was added to the suspension, and the resulting mixture was stirred at a room temperature for 2 hours. Further, 80 ml of water was added to the reaction mixture and stirred at a room temperature for 1 hour. The crystals formed were collected by filtration, washed with water, and dried. The crude crystals thus obtained were suspended in a mixture of chloroform:methanol=50:1 and stirred, the crystals were collected by filtration, and dissolved in a saturated sodium bicarbonate aqueous solution. The insoluble materials were removed by filtration, the filtrate obtained was neutralized with 10%-hydrochloric acid. The crystals formed were collected by filtration, washed with water, dried to obtain 3.2 g of 2-(4-chlorobenzoylamino)-3-(oxindol-3-yl)propionic acid monohydrate.

1. stirringstirred at a room temperature for 1 hour
2. customThe crystals formed
3. filtrationwere collected by filtration
4. washwashed with water
5. customdried
6. customThe crude crystals thus obtained
7. filtrationthe crystals were collected by filtration
8. dissolutiondissolved in a saturated sodium bicarbonate aqueous solution
9. customThe insoluble materials were removed by filtration
10. customthe filtrate obtained
11. customThe crystals formed
12. filtrationwere collected by filtration
13. washwashed with water
14. customdried