Chloroacetaldehyde → Ethyl imidazo[1,2-a]pyridine-8-carboxylate

HRID 1046526Notes

Reaction equation

HRID 1046526 reaction equation
[CH2:1]([O:3][C:4](=[O:12])[C:5]1[CH:10]=[CH:9][CH:8]=[N:7][C:6]=1[NH2:11])[CH3:2].Cl[CH2:14][CH:15]=O.C([O-])(O)=O.[Na+]>CCO>[CH2:1]([O:3][C:4]([C:5]1[C:6]2[N:7]([CH:14]=[CH:15][N:11]=2)[CH:8]=[CH:9][CH:10]=1)=[O:12])[CH3:2]

Participants

5

Reactant 3

HCID 33ChloroacetaldehydeHCID 516892Sodium BicarbonateHCID 12433260Ethyl 2-aminopyridine-3-carboxylate

Product 1

HCID 10867135Ethyl imidazo[1,2-a]pyridine-8-carboxylate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 2-amino-nicotinic acid ethyl ester (13.845 g), ClCH2CHO (58 mL), and NaHCO3 (11.85 g) was stirred in EtOH (500 mL) at reflux overnight. The reaction mixture was concentrated, diluted with H2O, and extracted with DCM. The product was purified by ISCO using 100% EtOAc first (to remove unreacted starting material), then using 100% DCM to 5% MeOH/DCM. The product eluted at 3% MeOH/DCM, providing imidazo[1,2-a]pyridine-8-carboxylic acid ethyl ester (10.5 g).

Workup

  1. temperatureat reflux overnight
  2. concentrationThe reaction mixture was concentrated
  3. additiondiluted with H2O
  4. extractionextracted with DCM
  5. customThe product was purified by ISCO
  6. custom100% EtOAc first (to remove unreacted starting material)
  7. washThe product eluted at 3% MeOH/DCM

Sources & evidence

ORD record
ord-f1c525b73ae34ebfb03b5afdde225f3e
Source dataset
uspto-grants-2013_10
Patent number
US08569306B2

Reaction notes

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