6-Methoxypyridine-3-carbaldehyde → 5-Ethenyl-2-methoxypyridine

HRID 657736Notes

Reaction equation

HRID 657736 reaction equation
[Br-].[C:2]1(C([PH3+])(C2C=CC=CC=2)C2C=CC=CC=2)C=CC=CC=1.[Li]CCCC.[CH3:27][O:28][C:29]1[CH:36]=[CH:35][C:32]([CH:33]=O)=[CH:31][N:30]=1>C1COCC1.CCCCCC.O>[CH3:27][O:28][C:29]1[CH:36]=[CH:35][C:32]([CH:33]=[CH2:2])=[CH:31][N:30]=1

Participants

7

Reactant 3

HCID 33645766-Methoxypyridine-3-carbaldehydeHCID 21951224Triphenylmethyl phosphonium bromideHCID 178418339Butyllithium

Product 1

HCID 230701355-Ethenyl-2-methoxypyridine

Reagents, catalysts & solvents 3

HCID 962WaterSolventHCID 8028TetrahydrofuranSolvent2×HCID 8058HexaneSolvent

Procedure

A suspension of triphenylmethylphosphonium bromide (31.2 g, 0.0875 mol) in THF (150 mL) at −78° C. under an atmosphere of nitrogen was added 2.5 M n-BuLi (38.0 mL, 0.0948 mol) in hexane during a period of 30 min. The reaction was warmed to room temperature to yield a deep red ylide solution. To the ylide solution, cooled in ice, was introduced 6-methoxynicotinaldehyde (10.0 g, 0.0729 mol) in THF (30 mL). The reaction was allowed to reach room temperature and stirred at room temperature for 3 h. Then the result suspension was heated to 60° C. over 30 minutes and heated at 60° C. for 1 hour. After cooling, the reaction was diluted with water (500 mL). The product was extracted into ethyl ether, washed with brine, dried (MgSO4), and concentrated. The residue was purified by silica gel column (0-40% EtOAc/hexane) to yield a light yellow oil. LC-MS: 136.0 [M+1]+;

Workup

  1. customto yield a deep red ylide solution
  2. temperatureTo the ylide solution, cooled in ice
  3. customto reach room temperature
  4. temperatureThen the result suspension was heated to 60° C. over 30 minutes
  5. temperatureheated at 60° C. for 1 hour
  6. temperatureAfter cooling
  7. extractionThe product was extracted into ethyl ether
  8. washwashed with brine
  9. dry with materialdried (MgSO4)
  10. concentrationconcentrated
  11. customThe residue was purified by silica gel column (0-40% EtOAc/hexane)
  12. customto yield a light yellow oil

Sources & evidence

ORD record
ord-e5f9f93505674eaca58a059fd323f4cf
Source dataset
uspto-grants-2011_12
Patent number
US08076345B2

Reaction notes

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