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

HRID 422276Notes

Reaction equation

HRID 422276 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=1.Br[CH2:9][C:10](=O)[C:11]([O:13][CH2:14][CH3:15])=[O:12]>C(O)C>[N:1]1[C:10]([C:11]([O:13][CH2:14][CH3:15])=[O:12])=[CH:9][N:3]2[CH:4]=[CH:5][CH:6]=[CH:7][C:2]=12

Participants

4

Reactant 2

HCID 104392-AminopyridineHCID 66144Ethyl bromopyruvate

Product 1

HCID 818807Ethyl imidazo[1,2-a]pyridine-2-carboxylateYield 62.8%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 2-amino-pyridine (2 g, 21 mmol) and ethyl bromopyruvate (4.14 g, 21 mmol) in ethanol (31 mL) was stirred under reflux for 24 h. The solvent was evaporated, and the residue was dissolved in a minimum volume of water. The solution was neutralized (pH==8) with saturated NaHCO3. The aqueous layer was extracted with AcOEt and the organic layer was washed with saturated NaCl. The solvent was removed under pressure to afford 2.51 g of ethyl imidazo[1,2-a]pyridine-2-carboxylate (Yield: 62%) as an orange oil which can be used without further purification.

Workup

  1. temperatureunder reflux for 24 h
  2. customThe solvent was evaporated
  3. dissolutionthe residue was dissolved in a minimum volume of water
  4. extractionThe aqueous layer was extracted with AcOEt
  5. washthe organic layer was washed with saturated NaCl
  6. customThe solvent was removed under pressure

Sources & evidence

ORD record
ord-c361042467c649bc951765f1e2d39888
Source dataset
uspto-grants-2012_01
Patent number
US08101637B2

Reaction notes

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