Propyltriphenylphosphonium bromide → 1-Carbobenzoxy-4-(1-butylidene)piperidine

HRID 223369

Reaction equation

HRID 223369 reaction equation
[CH2:1]([Li])[CH2:2][CH2:3][CH3:4].[Br-].C([P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)CC.[C:29]([N:39]1[CH2:44][CH2:43][C:42](=O)[CH2:41][CH2:40]1)([O:31][CH2:32][C:33]1[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=1)=[O:30]>O1CCCC1>[C:29]([N:39]1[CH2:44][CH2:43][C:42](=[CH:1][CH2:2][CH2:3][CH3:4])[CH2:41][CH2:40]1)([O:31][CH2:32][C:33]1[CH:38]=[CH:37][CH:36]=[CH:35][CH:34]=1)=[O:30]

Participants

5

Reactant 3

HCID 80374Propyltriphenylphosphonium bromideHCID 643496Benzyl 4-oxopiperidine-1-carboxylateHCID 178418339Butyllithium

Product 1

HCID 205220201-Carbobenzoxy-4-(1-butylidene)piperidine

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

Butyl lithium (44 ml of 1.6 M in hexane) was added slowly to a stirred suspension of 27 g of (n-propyl)triphenylphosphonium bromide in 350 ml of tetrahydrofuran and the resulting solution was refluxed for 1 hour. The mixture was cooled in an ice bath and 18 g of N-carbobenzyloxy-4-piperidone was added. After stirring at room temperature of 0.5 hour, the solution was refluxed for 2 hours. The cooled mixture was concentrated under reduced pressure, partitioned between ether and water, and the ether layer was dried (sodium sulfate) and evaporated. The residue was filtered through silica gel with 20% ethyl acetate-hexane to give 10 g of 1-carbobenzoxy-4-(1-butylidene)piperidine as a colorless oil.

Workup

  1. temperaturethe resulting solution was refluxed for 1 hour
  2. temperatureThe mixture was cooled in an ice bath
  3. temperaturethe solution was refluxed for 2 hours
  4. concentrationThe cooled mixture was concentrated under reduced pressure
  5. custompartitioned between ether and water
  6. dry with materialthe ether layer was dried (sodium sulfate)
  7. customevaporated
  8. filtrationThe residue was filtered through silica gel with 20% ethyl acetate-hexane

Sources & evidence

ORD record
ord-f068b0d416624defa98b220467acb3f2
Source dataset
uspto-grants-1982_10
Patent number
US04353901

Linked notes

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