Dimethylformamide → 5-Fluoropyridine-2-carboxaldehyde

HRID 2047457Notes

Reaction equation

HRID 2047457 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([F:8])=[CH:4][N:3]=1.C([Li])CCC.CN([CH:17]=[O:18])C.[Cl-].[NH4+]>C1(C)C=CC=CC=1>[F:8][C:5]1[CH:6]=[CH:7][C:2]([CH:17]=[O:18])=[N:3][CH:4]=1

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 25517Ammonium ChlorideHCID 27831712-Bromo-5-fluoropyridineHCID 178418339Butyllithium

Product 1

HCID 103516975-Fluoropyridine-2-carboxaldehydeYield 26%

Reagents, catalysts & solvents 1

HCID 1140TolueneSolvent

Conditions

Temperature
-78 °C

Procedure

To a solution of 2-bromo-5-fluoropyridine (25 g) in toluene (142 mL) was added at −78° C. n-butyllithium (2.5M toluene solution, 68 mL), and the mixture was stirred at −78° C. for 1 hr. To this mixture was added at −78° C. DMF (16.5 mL), and the mixture was stirred at −78° C. for 2 hr, and saturated aqueous ammonium chloride solution (300 mL) was added. The mixture was extracted with ethyl acetate (300 mL), dried and concentrated under reduced pressure. The residue was separated and purified by silica gel column chromatography (20% ethyl acetate/hexane) to give 5-fluoropyridine-2-carbaldehyde (4.7 g, 26%) as a yellow oil.

Workup

  1. additionTo this mixture was added at −78° C
  2. extractionThe mixture was extracted with ethyl acetate (300 mL)
  3. customdried
  4. concentrationconcentrated under reduced pressure
  5. customThe residue was separated
  6. custompurified by silica gel column chromatography (20% ethyl acetate/hexane)

Sources & evidence

ORD record
ord-9fdef8b65e9742429450c5f0fc37c0ad
Source dataset
uspto-grants-2013_11
Patent number
US08592454B2

Reaction notes

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