2-Bromonicotinaldehyde → 2-Bromo-3-ethenylpyridine

HRID 1099159Notes

Reaction equation

HRID 1099159 reaction equation
[CH2:1]([Li])CCC.[Br:6][C:7]1[N:14]=[CH:13][CH:12]=[CH:11][C:8]=1[CH:9]=O>[Br-].C[P+](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.C1COCC1>[Br:6][C:7]1[C:8]([CH:9]=[CH2:1])=[CH:11][CH:12]=[CH:13][N:14]=1

Participants

5

Reactant 2

HCID 47149512-BromonicotinaldehydeHCID 178418339Butyllithium

Product 1

HCID 534166352-Bromo-3-ethenylpyridine

Reagents, catalysts & solvents 2

HCID 74505Methyltriphenyliphosphonium bromideCatalystHCID 8028TetrahydrofuranSolvent2×

Conditions

Temperature
0 °C

Procedure

See Spivey, A. C.; Shukla, L.; Hayler, J. F. Org. Lett. 2007, 9, 891-894. Butyllithium (22.75 mL, 59.1 mmol) was added to the THF (450 mL) suspension of methyltriphenylphosphonium bromide (21.13 g, 59.1 mmol) at 0° C. The solution turned to orange and the reaction was lift to room temperature for 30 min before cooled it back to 0° C. 2-bromonicotinaldehyde (10 g, 53.8 mmol) in 50 mL THF was added through canula to the reaction solution. The precipitate was formed and the reaction was lift to room temperature. The color of the reaction turned to green, gray. After a while, the color of to reaction became orange again. The reaction was stirred at room temperature over weekend. The solvent was removed mostly via vacuum and the crude was partitioned between water and diethyl ether. The organic layer was separated and the aqueous layer was extract twice with diethyl ether. The diethyl ether layer was combined, dried (Na2SO4), filtered and concentrated. The product was obtained by flash column eluted with ethyl acetate in hexane (10%) as yellow oil (8.78 g, 89%). MS (ESI)[M+H+]=184.04; 1H NMR δ ppm (400 MHz, CHLOROFORM-d) 8.21-8.29 (m, 1H) 7.78 (dd, J=7.68, 1.89 Hz, 1H) 7.20-7.28 (m, 1H) 6.96 (dd, J=17.37, 11.08 Hz, 1H) 5.72 (d, J=17.37 Hz, 1H) 5.46 (d, J=11.08 Hz, 1H).

Workup

  1. customto room temperature
  2. customfor 30 min
  3. customThe precipitate was formed
  4. customto room temperature
  5. customAfter a while, the color of to reaction
  6. customThe solvent was removed mostly via vacuum
  7. customthe crude was partitioned between water and diethyl ether
  8. customThe organic layer was separated
  9. extractionthe aqueous layer was extract twice with diethyl ether
  10. dry with materialdried (Na2SO4)
  11. filtrationfiltered
  12. concentrationconcentrated
  13. customThe product was obtained by flash column
  14. washeluted with ethyl acetate in hexane (10%) as yellow oil (8.78 g, 89%)

Sources & evidence

ORD record
ord-1b03a9e091164b3fbd566d1255dc48ca
Source dataset
uspto-grants-2012_03
Patent number
US08143403B2

Reaction notes

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