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

HRID 334548Notes

Reaction equation

HRID 334548 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-365fa8e003334baa88f3d985f4ade44a
Source dataset
uspto-grants-2014_11
Patent number
US08883826B2

Reaction notes

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