反应详情

A solution of 6.14 g (19.0 mmoles) 1-benzoyl-4-(phenylmethyl)-4-piperidinecarboxylic acid in 61 ml concentrated sulfuric acid was stirred 18 hours at room temperature to give a deep red solution. The solution was carefully diluted with ice-bath cooling with 300 ml H2O and extracted with 3×300 ml ethyl acetate. The extract was washed with 25 ml water and brine, dried, and the solvent was removed in vacuo to give a white foam. The foam was stirred under ether and filtered off to give 3.61 g (62%) product, m.p. 149°-154° C.

1. customto give a deep red solution
2. additionThe solution was carefully diluted with ice-bath
3. extractionextracted with 3×300 ml ethyl acetate
4. washThe extract was washed with 25 ml water and brine
5. customdried
6. customthe solvent was removed in vacuo
7. customto give a white foam
8. filtrationfiltered off