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

HRID 2229202Notes

Reaction equation

HRID 2229202 reaction equation
Br[CH2:2][C:3](=O)[C:4]([O:6][CH2:7][CH3:8])=[O:5].[NH2:10][C:11]1[CH:16]=N[CH:14]=[CH:13][N:12]=1.[C:17](=O)([O-])[O-].[K+].[K+]>C(O)C>[N:10]1[C:3]([C:4]([O:6][CH2:7][CH3:8])=[O:5])=[CH:2][N:12]2[CH:13]=[CH:14][CH:17]=[CH:16][C:11]=12

Participants

5

Reactant 3

HCID 11430Potassium CarbonateHCID 66144Ethyl bromopyruvateHCID 78747Aminopyrazine

Product 1

HCID 818807Ethyl imidazo[1,2-a]pyridine-2-carboxylateYield 61.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A solution of 7.8 g (40 mmol) of ethyl bromopyruvate and in 40 mL of ethanol is treated with 3.76 g (30.0 mmol) of 2-aminopyrazine and heated to reflux temperature for 16 hr. The reaction mixture is cooled to room temperature and treated with 10 g of potassium carbonate. The mixture is filtered through Celite and the solvent removed in vacuo to yield the crude material. The resulting residue is flash chromatographed with initially 1% methanol in dichloromethane to afford 3.5 g (46%) ethyl imidazolo[1,2-a]pyridine-2-carboxylate.

Workup

  1. temperatureheated
  2. temperatureto reflux temperature for 16 hr
  3. filtrationThe mixture is filtered through Celite
  4. customthe solvent removed in vacuo
  5. customto yield the crude material
  6. customchromatographed with initially 1% methanol in dichloromethane

Sources & evidence

ORD record
ord-2aa0eb41a0174585ba1c422b9ae300ed
Source dataset
uspto-grants-2002_07
Patent number
US06420365B1

Reaction notes

Loading…