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

HRID 1615667Notes

Reaction equation

HRID 1615667 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]>C1COCC1>[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 60.3%

Reagents, catalysts & solvents 1

HCID 8028TetrahydrofuranSolvent

Procedure

A solution of 2-aminopyridine (5.0 g, 53.2 mmol) in THF (150 mL) was treated with ethyl bromopyruvate (10.32 g, 57.0 mmol) at room temperature followed by heating the mixture at reflux for 16 h. The resulting white precipitate was collected by filtration and washed with THF (10 mL). Recrystallization of the solids from boiling EtOH (20 mL) gave ethyl imidazo[1,2-a]pyridine-2-carboxylate (6.10 g, 60% yield). ESI MS: m/z 191 [M+1]+. See, e.g., J. Med. Chem., 2003, 46, 3914-29.

Workup

  1. temperatureby heating the mixture
  2. temperatureat reflux for 16 h
  3. filtrationThe resulting white precipitate was collected by filtration
  4. washwashed with THF (10 mL)
  5. customRecrystallization of the solids

Sources & evidence

ORD record
ord-fb4d2943e8764553b9d5d62e90ddf0a5
Source dataset
uspto-grants-2014_07
Patent number
US08765760B2

Reaction notes

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