1-(4-Nitrophenyl)piperidin-4-one → 4-Methylidene-1-(4-nitrophenyl)piperidine

HRID 1910777Notes

Reaction equation

HRID 1910777 reaction equation
[Li][CH2:2][CH2:3][CH2:4][CH3:5].[N+:6]([C:9]1[CH:14]=[CH:13][C:12]([N:15]2CCC(=O)[CH2:17][CH2:16]2)=[CH:11][CH:10]=1)([O-:8])=[O:7]>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C1COCC1>[CH2:5]=[C:4]1[CH2:17][CH2:16][N:15]([C:12]2[CH:11]=[CH:10][C:9]([N+:6]([O-:8])=[O:7])=[CH:14][CH:13]=2)[CH2:2][CH2:3]1

Participants

5

Reactant 2

HCID 38425621-(4-Nitrophenyl)piperidin-4-oneHCID 178418339Butyllithium

Product 1

HCID 671069544-Methylidene-1-(4-nitrophenyl)piperidineYield 61.1%

Reagents, catalysts & solvents 2

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 8028TetrahydrofuranSolvent2×

Procedure

To a solution of methyltriphenylphosphonium bromide (1.07 g, 3 mmol) in THF (10 mL) was added 2.5 M n-BuLi solution (1.6 mL, 4 mmol) at −70° C. The mixture was warmed to r.t. and stirred for 15 min then cooled once more to −70° C. A solution of 1-(4-nitro-phenyl)-piperidin-4-one (396 mg, 1.8 mmol) in THF (10 mL) was added then the mixture was allowed to warm to r.t. and stirred overnight. The reaction was quenched by addition of ice and extracted with ethyl acetate. The combined organic layers were then washed with water, brine and dried over sodium sulfate. Concentration to dryness afforded 4-methylene-1-(4-nitrophenyl)-piperidine (240 mg, 61%) as a solid.

Workup

  1. temperaturethen cooled once more to −70° C
  2. temperatureto warm to r.t.
  3. stirringstirred overnight
  4. customThe reaction was quenched by addition of ice
  5. extractionextracted with ethyl acetate
  6. washThe combined organic layers were then washed with water, brine
  7. dry with materialdried over sodium sulfate
  8. concentrationConcentration to dryness

Sources & evidence

ORD record
ord-f68a0f542f544933be371cebbbb86cca
Source dataset
uspto-grants-2013_12
Patent number
US08604029B2

Reaction notes

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