Hydrogen Bromide → 3-[(4-Fluorophenyl)(1-methyl-4-piperidinylidene)methyl]pyridine

HRID 1380244Notes

Reaction equation

HRID 1380244 reaction equation
[F:1][C:2]1[CH:7]=[CH:6][C:5]([C:8]([CH:16]2[CH2:21][CH2:20][N:19]([CH3:22])[CH2:18][CH2:17]2)([C:10]2[CH:11]=[N:12][CH:13]=[CH:14][CH:15]=2)O)=[CH:4][CH:3]=1.Br>O>[F:1][C:2]1[CH:3]=[CH:4][C:5]([C:8](=[C:16]2[CH2:21][CH2:20][N:19]([CH3:22])[CH2:18][CH2:17]2)[C:10]2[CH:11]=[N:12][CH:13]=[CH:14][CH:15]=2)=[CH:6][CH:7]=1

Participants

4

Reactant 2

HCID 260Hydrogen BromideHCID 23326054alpha-(4-Fluorophenyl)-alpha-(1-methyl-4-piperidinyl)-3-pyridinemethanol

Product 1

HCID 135200163-[(4-Fluorophenyl)(1-methyl-4-piperidinylidene)methyl]pyridineYield 48%

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 240 parts of α-(4-fluorophenyl)-α-(1-methyl-4-piperidinyl)-3-pyridinemethanol and 900 parts of a hydrobromic acid solution 48% in water was stirred and refluxed for 1 hour. The whole was concentrated to one third of its volume. The concentrate was treated with a sodium hydroxide solution. The product was extracted with 4-methyl-2-pentanone. The extract was dried, filtered and evaporated. The residue was purified by column-chromatography over silica gel using a mixture of trichloromethane and methanol (90:10 by volume), saturated with ammonia, as eluent. The pure fractions were collected and the eluent was evaporated. The residue was crystallized from a mixture of petroleumether and a small amount of 2,2'-oxybispropane (10:1 by volume). The product was filtered off and dried, yielding 112.5 parts (48%) of 3-[(4-fluorophenyl)(1-methyl-4-piperidinylidene)methyl]pyridine; mp. 93.1° C. (intermediate 19).

Workup

  1. temperaturerefluxed for 1 hour
  2. concentrationThe whole was concentrated to one third of its volume
  3. additionThe concentrate was treated with a sodium hydroxide solution
  4. extractionThe product was extracted with 4-methyl-2-pentanone
  5. customThe extract was dried
  6. filtrationfiltered
  7. customevaporated
  8. customThe residue was purified by column-chromatography over silica gel using
  9. additiona mixture of trichloromethane and methanol (90:10 by volume)
  10. customThe pure fractions were collected
  11. customthe eluent was evaporated
  12. customThe residue was crystallized from a mixture of petroleumether
  13. filtrationThe product was filtered off
  14. customdried

Sources & evidence

ORD record
ord-632ef5e6f3cb4e28858b05f998f29647
Source dataset
uspto-grants-1986_04
Patent number
US04581171

Reaction notes

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