Ammonium Chloride → 1-Boc-4-Methylenepiperidine

HRID 1619729Notes

Reaction equation

HRID 1619729 reaction equation
[CH3:1]C([O-])(C)C.[K+].[C:7]([N:14]1[CH2:19][CH2:18][C:17](=O)[CH2:16][CH2:15]1)([O:9][C:10]([CH3:13])([CH3:12])[CH3:11])=[O:8].[NH4+].[Cl-]>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C(OCC)C>[C:10]([O:9][C:7]([N:14]1[CH2:19][CH2:18][C:17](=[CH2:1])[CH2:16][CH2:15]1)=[O:8])([CH3:13])([CH3:12])[CH3:11]

Participants

6

Reactant 3

HCID 25517Ammonium ChlorideHCID 735900tert-Butyl 4-oxopiperidine-1-carboxylateHCID 23665647Potassium tert-butoxide

Product 1

HCID 27568081-Boc-4-MethylenepiperidineYield 89%

Reagents, catalysts & solvents 2

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 3283Diethyl EtherSolvent2×

Conditions

Temperature
0 °C

Procedure

1.6 g (14 mmol) potassium tert-butylate were added to a suspension of 5.34 g (15 mmol) methyltriphenylphosphonium bromide in 50 ml diethyl ether while stirring at 0° C. (ice bath). After stirring for 15 min, a solution of 2.00 g (10 mmol) 1-Boc-4-piperidone (A) in 15 ml diethyl ether was added slowly. The suspension was stirred for a further 30 min at 0° C. After the addition of 60 ml 10% aq. NH4Cl solution, the organic phase was separated off, dried over magnesium sulphate and desolventised under vacuum. After chromatography on silica gel (hexane:EtOAc=5:1), 1.71 g (89%) 4-methylene piperidine-1-carboxylic acid tert-butyl ester (B) were obtained as a colourless liquid.

Workup

  1. stirringAfter stirring for 15 min
  2. stirringThe suspension was stirred for a further 30 min at 0° C
  3. customthe organic phase was separated off
  4. dry with materialdried over magnesium sulphate

Sources & evidence

ORD record
ord-31ee7db802f84a6a97462c2c1273516a
Source dataset
uspto-grants-2014_07
Patent number
US08772307B2

Reaction notes

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