Dimethylformamide → 5-Chloropyridine-2-carboxaldehyde

HRID 332000Notes

Reaction equation

HRID 332000 reaction equation
Br[C:2]1[CH:7]=[CH:6][C:5]([Cl:8])=[CH:4][N:3]=1.C([Mg]Cl)(C)C.[Li+].[Cl-].CN([CH:19]=[O:20])C>C1COCC1>[Cl:8][C:5]1[CH:6]=[CH:7][C:2]([CH:19]=[O:20])=[N:3][CH:4]=1

Participants

6

Reactant 4

HCID 6228DimethylformamideHCID 433294Lithium ChlorideHCID 8170982-Bromo-5-chloropyridineHCID 178418918HCID 178418918, compound

Product 1

HCID 101032675-Chloropyridine-2-carboxaldehydeYield 57.2%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Conditions

Temperature
0 °C

Procedure

To a solution of 2-bromo-5-chloropyridine (14.8 g, 77 mmol) in THF (38.5 mL) was added dropwise a solution of i-PrMgCl.LiCl (14% in THF, 81 mL, 85 mmol) at 0-5° C. and the resulting mixture stirred at 0° C. for 1 h. Then DMF (7.7 mL, 100 mmol) was added dropwise at −5° C. and the temperature maintained at 0° C. for 2 h. The reaction mixture was then poured into ice cold saturated brine (500 mL) and then extracted with ethyl acetate (2×300 mL). The combined organic layers were washed with saturated sodiumhydrogencarbonate solution, brine, dried over sodium sulfate, filtered and evaporated. Purification by chromatography (SiO2, heptane:ethyl acetate=1:0 to 9:1) afforded the title compound (6.24 g, 57%) which was obtained as a brown solid. MS: m/e=141.0 [M]+.

Workup

  1. extractionextracted with ethyl acetate (2×300 mL)
  2. washThe combined organic layers were washed with saturated sodiumhydrogencarbonate solution, brine
  3. dry with materialdried over sodium sulfate
  4. filtrationfiltered
  5. customevaporated
  6. customPurification by chromatography (SiO2, heptane:ethyl acetate=1:0 to 9:1)

Sources & evidence

ORD record
ord-cc13b36671ee4863873dd0bc4b1788cc
Source dataset
uspto-grants-2014_11
Patent number
US08877782B2

Reaction notes

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