Ethyl bromopyruvate → Ethyl 7-methoxyimidazo[1,2-a]pyridine-2-carboxylate

HRID 2175439Notes

Reaction equation

HRID 2175439 reaction equation
[NH2:1][C:2]1[CH:7]=[C:6]([O:8][CH3:9])[CH:5]=[CH:4][N:3]=1.Br[CH2:11][C:12](=O)[C:13]([O:15][CH2:16][CH3:17])=[O:14]>C(O)C>[CH3:9][O:8][C:6]1[CH:5]=[CH:4][N:3]2[CH:11]=[C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])[N:1]=[C:2]2[CH:7]=1

Participants

4

Reactant 2

HCID 66144Ethyl bromopyruvateHCID 108987152-Amino-4-Methoxypyridine

Product 1

HCID 20072865Ethyl 7-methoxyimidazo[1,2-a]pyridine-2-carboxylateYield 58.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 2-amino-4-methoxypyridine (1.0 g, 8.1 mmol) and ethyl 3-bromo-2-oxopropanoate (1.77 g, 9.1 mmol) in ethanol (10 mL) was refluxed for 6 h. After the reaction was concentrated, ethyl acetate (20 mL) was added to the residue. The mixture was basified by saturated aqueous sodium bicarbonate. The separated organic layer was washed with brine and dried over sodium sulfate. The solvent was evaporated and the residue obtained was purified by flash chromatography (silica gel, methylene chloride/ethyl acetate=1/1) to afford ethyl 7-methoxyimidazo[1,2-a]pyridine-2-carboxylate as a solid (1.04 g, 58%). 1H-NMR (DMSO-d6, 300 MHz): δ 8.37 (m, 2H), 6.91 (s, 1H), 6.70 (m, 1H), 4.25 (m, 2H), 3.81 (s, 3H), 1.28 (m, 3H) ppm; MS (ESI): 221.1 (M+1).

Workup

  1. temperaturewas refluxed for 6 h
  2. concentrationAfter the reaction was concentrated
  3. additionethyl acetate (20 mL) was added to the residue
  4. washThe separated organic layer was washed with brine
  5. dry with materialdried over sodium sulfate
  6. customThe solvent was evaporated
  7. customthe residue obtained
  8. customwas purified by flash chromatography (silica gel, methylene chloride/ethyl acetate=1/1)

Sources & evidence

ORD record
ord-4f6ea7d68d5f43fc8ccd06e24e9254b8
Source dataset
uspto-grants-2015_06
Patent number
US09062052B2

Reaction notes

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