Methyl iodide → Methyl imidazo(1,2-a)pyridine-6-carboxylate

HRID 1394650Notes

Reaction equation

HRID 1394650 reaction equation
[C:1](=O)([O-])[O-].[Cs+].[Cs+].IC.[N:9]1[CH:10]=[CH:11][N:12]2[CH:17]=[C:16]([C:18]([OH:20])=[O:19])[CH:15]=[CH:14][C:13]=12>CN(C=O)C.[Cl-].[Na+].O>[CH3:1][O:19][C:18]([C:16]1[CH:15]=[CH:14][C:13]2[N:12]([CH:11]=[CH:10][N:9]=2)[CH:17]=1)=[O:20]

Participants

6

Reactant 3

HCID 6328Methyl iodideHCID 10796Cesium carbonateHCID 7075376Imidazo(1,2-a)pyridine-6-carboxylic acid

Product 1

HCID 2764326Methyl imidazo(1,2-a)pyridine-6-carboxylateYield 39%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 57417360Sodium chloride; waterSolvent

Procedure

Cesium carbonate (15.7 g, 48.2 mmol) and iodomethane (1.50 ml, 24.2 mmol) were added to a solution of imidazo[1,2-a]pyridine-6-carboxylic acid (2.61 g, 16.1 mmol) in DMF (100 ml). The reaction was stirred at ambient temperature overnight, then poured into brine (100 ml) and extracted with ethyl acetate (3×100 mL). The combined organics were washed with saturated sodium bicarbonate solution (25 mL), and a 1N HCl solution (25 mL) then dried over MgSO4 and evaporated to give imidazo[1,2-a]pyridine-6-carboxylic acid methyl ester as a yellow solid (1.1 g, 39%). 1H NMR (250 MHz, CDCl3): δ 8.96 (s, 1H), 7.8-7.6 (m, 4H), 3.98 (s, 3H). MS [EI+] 177 (M+H)+.

Workup

  1. extractionextracted with ethyl acetate (3×100 mL)
  2. washThe combined organics were washed with saturated sodium bicarbonate solution (25 mL)
  3. dry with materiala 1N HCl solution (25 mL) then dried over MgSO4
  4. customevaporated

Sources & evidence

ORD record
ord-a83c10edaebf41949a0e6ed0fef7acde
Source dataset
uspto-grants-2008_03
Patent number
US07348359B2

Reaction notes

Loading…