反应详情

A solution of 10.2 g. of 4-(1-piperidyl)-cyclohexanone, 8.1 g. of 2,4-difluorophenylhydrazine, and 11 g. of methanesulfonic acid in 100 ml. of absolute ethyl alcohol was heated under reflux for twelve hours, cooled, filtered, and the filtrate was evaporated to dryness under reduced pressure. The residue was treated in ether with 10% potassium hydroxide solution and the ether extract was washed with water, dried, and treated with hydrogen chloride in ethyl alcohol (excess HCl was avoided). The resulting gummy precipitate was separated by decantation and suspended in boiling isopropyl alcohol. The hot mixture was filtered to give, after recrystallization from absolute ethyl alcohol, 4.5 g. of 3-(1-piperidyl)-6,8-difluoro-1,2,3,4-tetrahydrocarbazole hydrochloride, m.p. >290° C.

1. temperatureunder reflux for twelve hours
2. temperaturecooled
3. filtrationfiltered
4. customthe filtrate was evaporated to dryness under reduced pressure
5. additionThe residue was treated in ether with 10% potassium hydroxide solution
6. extractionthe ether extract
7. washwas washed with water
8. customdried
9. additiontreated with hydrogen chloride in ethyl alcohol (excess HCl was avoided)
10. customThe resulting gummy precipitate was separated by decantation
11. filtrationThe hot mixture was filtered
12. customto give
13. customafter recrystallization from absolute ethyl alcohol, 4.5 g