反应详情

A mixture of 100 parts of ethyl 4-[(4-fluorophenyl)(3-pyridinyl)methylene]-1-piperidinecarboxylate and 375 parts of a hydrobromic acid solution 48% was stirred and refluxed for 3 hours. The reaction mixture was evaporated. The residue was washed with 2,2'-oxybispropane. The latter was decanted, the residue was stirred in water and the whole was alkalized with a sodium hydroxide solution. The product was extracted with trichloromethane. The extract was dried, filtered and evaporated. The residue was purified by column-chromatography (2×) over silica gel using a mixture of trichloromethane and methanol, saturated with ammonia, (80:20 by volume) as eluent. The main fraction was collected and the eluent was evaporated, yielding 30 parts (37%) of 3-[(4-fluorophenyl)(4-piperidinylidene)methyl]pyridine as a residue (intermediate 21).

1. temperaturerefluxed for 3 hours
2. customThe reaction mixture was evaporated
3. washThe residue was washed with 2,2'-oxybispropane
4. customThe latter was decanted
5. stirringthe residue was stirred in water
6. extractionThe product was extracted with trichloromethane
7. customThe extract was dried
8. filtrationfiltered
9. customevaporated
10. customThe residue was purified by column-chromatography (2×) over silica gel using
11. additiona mixture of trichloromethane and methanol
12. customThe main fraction was collected
13. customthe eluent was evaporated