反应详情

A solution of 20 g (122.56 mmol) of 2(S)-indolinecarboxylic acid in 2N NaOH (62 ml) is cooled in an ice/water bath and the solution is stirred using a powerful magnetic stirrer. 20.0 ml (140.09 mmol) of benzyl chloroformate and 68 ml of 2N NaOH are added thereto alternately in about 10 portions over 60 minutes. The temperature of the reaction mixture is maintained between 0° and 5° C. by controlling the rate of addition of the reactants. 50 ml of NaOH are then added and the mixture is maintained at room temperature for 30 minutes. The alkaline solution is washed with ether (4×150 ml) and is then acidified by addition of 5N HCl (80 ml, pH<2). A crystalline mass precipitates after leaving overnight at room temperature. It is filtered off and washed with distilled water (500 ml). After drying over P2O5, the desired product is obtained.

1. temperatureThe temperature of the reaction mixture is maintained between 0° and 5° C.
2. additionthe rate of addition of the reactants
3. washThe alkaline solution is washed with ether (4×150 ml)
4. additionis then acidified by addition of 5N HCl (80 ml, pH<2)
5. customA crystalline mass precipitates
6. customafter leaving overnight at room temperature
7. filtrationIt is filtered off
8. washwashed with distilled water (500 ml)
9. dry with materialAfter drying over P2O5