反应详情

温度

5 °C

4-N-propylamino-cyclohexanone-ethyleneketal 2 (134 g, 0.673 mol) was taken in tetrahydrofuran (268 ml) and cooled to 4-6° C. Concentrated hydrochloric acid (178 ml, 2.01 mol) was diluted with water (2144 ml) and the mixture was cooled to 4° C. This diluted hydrochloric acid was added to the reaction mixture at 4-6° C. in 15 minutes. The reaction was allowed to come to 24-26° C. and stirring was continued for 24 hours. The reaction mass (2750 ml) was concentrated to 1800 ml at 50° C. and 35 mbar pressure. Sodium carbonate (148 g, 1.4 mol) was added to achieve pH 10. The reaction mixture was extracted with dichloromethane (3670 ml). The dichloromethane layers were combined and dried over sodium sulfate (20 g). The dichloromethane layer was concentrated to dryness at 40° C. and 15 mbar pressure. The product 3 was yellow viscous oil. The weight of the product 3 obtained was 52.5 g (52.84%); GC purity 86.07%.

1. temperaturethe mixture was cooled to 4° C
2. customto come to 24-26° C.
3. concentrationThe reaction mass (2750 ml) was concentrated to 1800 ml at 50° C.
4. extractionThe reaction mixture was extracted with dichloromethane (3670 ml)
5. dry with materialdried over sodium sulfate (20 g)
6. concentrationThe dichloromethane layer was concentrated to dryness at 40° C.