Sodium Carbonate → 5-Methyl-6-(pyridin-3-yl) imidazo[1,2-a]pyridine-3-carbaldehyde

HRID 401454Notes

Reaction equation

HRID 401454 reaction equation
Br[C:2]1[CH:3]=[CH:4][C:5]2[N:6]([C:9]([CH:12]=[O:13])=[CH:10][N:11]=2)[C:7]=1[CH3:8].[N:14]1[CH:19]=[CH:18][CH:17]=[C:16](B(O)O)[CH:15]=1.C([O-])([O-])=O.[Na+].[Na+]>CN(C=O)C.C(OCC)(=O)C>[CH3:8][C:7]1[N:6]2[C:9]([CH:12]=[O:13])=[CH:10][N:11]=[C:5]2[CH:4]=[CH:3][C:2]=1[C:16]1[CH:15]=[N:14][CH:19]=[CH:18][CH:17]=1

Participants

6

Reactant 3

HCID 10340Sodium CarbonateHCID 27343783-Pyridinylboronic acidHCID 866706016-Bromo-5-methylimidazo[1,2-a]pyridine-3-carbaldehyde

Product 1

HCID 866705995-Methyl-6-(pyridin-3-yl) imidazo[1,2-a]pyridine-3-carbaldehydeYield 40%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 8857Ethyl AcetateSolvent

Procedure

6-bromo-5-methylimidazo[1,2-a]pyridine-3-carbaldehyde (125 mg, 0.523 mmol), Pyridine-3-boronic acid (77.5 mg, 0.603 mmol), dichlorobis(triphenylphosphine) palladium (II) (36.7 mg, 0.05 mmol) and 2M aqueous Na2CO3 (2 ml) were dissolved in DMF (3 ml) and refluxed for 2 hours. The reaction mixture was diluted with ethyl acetate and washed with water and brine. The solvent was evaporated to obtain crude product, which was purified by column chromatography (silica gel, 0.5% methanol in chloroform) to obtain the title compound. Yield: 40%; 1H NMR (DMSO-d6; 300 MHz): 69.90(s, 1H), 8.39 (s, 1H), 7.73 (d, 1H, J=9.6 Hz), 7.56 (d, 1H, J=9.3 Hz), 3.11 (s, 3H); MS: m/z 238 (M+1)+.

Workup

  1. temperaturerefluxed for 2 hours
  2. washwashed with water and brine
  3. customThe solvent was evaporated
  4. customto obtain crude product, which
  5. customwas purified by column chromatography (silica gel, 0.5% methanol in chloroform)

Sources & evidence

ORD record
ord-089d1b56102b4ae299d31db6029a2053
Source dataset
uspto-grants-2014_06
Patent number
US08741932B2

Reaction notes

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