Benzyl Bromide → 4-Benzyl-4-piperidinol

HRID 1391061Notes

Reaction equation

HRID 1391061 reaction equation
[Mg].[CH2:2](Br)[C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1.C([N:17]1[CH2:22][CH2:21][C:20](=[O:23])[CH2:19][CH2:18]1)C1C=CC=CC=1.[Cl-].[NH4+].[H][H]>C(OCC)C.C(O)C.C(O)(=O)C.[Pd]>[CH2:2]([C:20]1([OH:23])[CH2:21][CH2:22][NH:17][CH2:18][CH2:19]1)[C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][CH:4]=1

Participants

10

Reactant 5

HCID 7498Benzyl BromideHCID 192201-Benzyl-4-piperidoneHCID 25517Ammonium ChlorideHCID 5462224MagnesiumHCID 178418361HCID 178418361, compound

Product 1

HCID 981524-Benzyl-4-piperidinol

Reagents, catalysts & solvents 4

HCID 23938PalladiumCatalystHCID 176Acetic AcidSolventHCID 702EthanolSolventHCID 3283Diethyl EtherSolvent2×

Procedure

To the Grignard reagent, prepared from 3.6 g of magnesium and 18.9 g of benzyl bromide in 50 ml of diethyl ether, the solution of 18.4 g of 1-benzyl-4-piperidone in 100 ml of diethyl ether is added and the mixture refluxed for one hour. It is decomposed with 30 ml of saturated aqueous ammonium chloride, the ethereal solution separated, dried and evaporated, leaving a thick oil. 26 g thereof are hydrogenated in a mixture of 120 ml of ethanol and 120 ml of acetic acid over 3 g of 10% palladium on carbon at 3 at. and 50° until one molar equivalent of hydrogen has been taken up. It is filtered, the filtrate evaporated, the residue treated with ammonium hydroxide and extracted with methylene chloride. The extract is dried and evaporated, to yield the 4-benzyl-4-hydroxy-piperidine, which is pure enough for further reaction.

Workup

  1. temperaturethe mixture refluxed for one hour
  2. customthe ethereal solution separated
  3. customdried
  4. customevaporated
  5. customleaving a thick oil
  6. custom50°
  7. filtrationIt is filtered
  8. customthe filtrate evaporated
  9. additionthe residue treated with ammonium hydroxide
  10. extractionextracted with methylene chloride
  11. customThe extract is dried
  12. customevaporated

Sources & evidence

ORD record
ord-1c06fb31baea4aa2902688d013f13cd5
Source dataset
uspto-grants-1979_02
Patent number
US04140781

Reaction notes

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