反应详情

A 2-l. three-necked flask, equipped with a thermometer, a mechancal stirrer and a dropping funnel was charged with 101.2 g (ca. 0.35 moles) of crude pulverized alpha-amino-6-chloro-3-indoleacrylic acid methylester hydrochloride and 400 ml of acetic anhydride. The slurry was cooled to 15°. Then 32 g (0.40 moles) of pyridine was added with stirring over a 5 minute period, while the temperature was kept between 15° and 22°; after complete addition, virtually all starting hydrochloride went into solution. Stirring at 22° was continued for 20 minutes during which the product began to crystallize out. 200 ml of water was then added over 40 minutes, keeping the temperature at ca. 25°. Stirring at this temperature was continued for 11/2 hours. 900 ml of water was then added over 5 minutes and the slurry stirred at room temperature for an additional hour. The precipitate was collected by suction filtration, washed with 750 ml of water and dried at 60° (constant weight) to afford 92.9 g (90%) of product, as yellow crystals, m.p. 202-203°.

1. customthree-necked flask, equipped with a thermometer, a mechancal stirrer and a dropping funnel
2. additionwas charged with 101.2 g (ca. 0.35 moles) of crude
3. temperatureThe slurry was cooled to 15°
4. customwas kept between 15° and 22°
5. additionafter complete addition
6. stirringStirring at 22°
7. waitwas continued for 20 minutes during which
8. customto crystallize out
9. addition200 ml of water was then added over 40 minutes
10. customat ca. 25°
11. stirringStirring at this temperature
12. custom2 hours
13. addition900 ml of water was then added over 5 minutes
14. stirringthe slurry stirred at room temperature for an additional hour
15. filtrationThe precipitate was collected by suction filtration
16. washwashed with 750 ml of water
17. customdried at 60° (constant weight)