反应详情

To a solution of sodium ethoxide, prepared from 3.2 g (133 mmol) of sodium metal and 200 mL of absolute ethanol, at ambient temperature was added 8.3 g (74 mmol) of trifluoroacetamidine followed by 17.8 g (60 mmol) of ethyl 1-benzyl-3-oxopiperidine-4-carboxylate hydrochloride in portions over 15 min. The reaction mixture was stirred at ambient temperature for 1 h, then heated at reflux for 30 h. The mixture was concentrated in vacuo. The resultant red foam was partitioned between 300 mL of 1N aqueous sodium hydroxide solution and 300 mL of ether. The aqueous layer was washed with 300 mL of ether and the combined ether phases were extracted with 50 mL of 1N aqueous sodium hydroxide solution. The combined aqueous phases were cooled in an ice-water bath and neutralized to pH 7 with concentration hydrochloric acid. The solids were collected, washed with water, and dried in vacuo to give the title compound as a beige solid, which was used as is. An analytical sample was prepared by recrystallization from isopropanol to give a white solid. LC-MS 310.0 (M+1).

1. temperatureheated
2. temperatureat reflux for 30 h
3. concentrationThe mixture was concentrated in vacuo
4. customThe resultant red foam was partitioned between 300 mL of 1N aqueous sodium hydroxide solution and 300 mL of ether
5. washThe aqueous layer was washed with 300 mL of ether
6. extractionthe combined ether phases were extracted with 50 mL of 1N aqueous sodium hydroxide solution
7. temperatureThe combined aqueous phases were cooled in an ice-water bath
8. concentrationneutralized to pH 7 with concentration hydrochloric acid
9. customThe solids were collected
10. washwashed with water
11. customdried in vacuo