Ethyl bromopyruvate → 2,8-Diethyl imidazo[1,2-a]pyridine-2,8-dicarboxylate

HRID 1440470Notes

Reaction equation

HRID 1440470 reaction equation
Br[CH2:2][C:3](=O)[C:4]([O:6][CH2:7][CH3:8])=[O:5].[NH2:10][C:11]1[N:21]=[CH:20][CH:19]=[CH:18][C:12]=1[C:13]([O:15][CH2:16][CH3:17])=[O:14]>C(C(C)=O)C>[CH2:7]([O:6][C:4]([C:3]1[N:10]=[C:11]2[C:12]([C:13]([O:15][CH2:16][CH3:17])=[O:14])=[CH:18][CH:19]=[CH:20][N:21]2[CH:2]=1)=[O:5])[CH3:8]

Participants

4

Reactant 2

HCID 66144Ethyl bromopyruvateHCID 12433260Ethyl 2-aminopyridine-3-carboxylate

Product 1

HCID 189838522,8-Diethyl imidazo[1,2-a]pyridine-2,8-dicarboxylateYield 26.7%

Reagents, catalysts & solvents 1

HCID 6569Methyl Ethyl KetoneSolvent

Procedure

A mixture of ethyl bromopyruvate (2.3 g, 10.2 m mol and ethyl 2-aminonicotinate (1.7 g, 10 m mol) in methyl ethyl ketone (17 ml) was refluxed for 5 hours. After completion of the reaction, the mixture was cooled to room temperature and distilled under reduced pressure to remove the solvent. The residue to which saturated sodium hydrogen carbonate aqueous solution (50 ml) was added was extracted with chloroform (100 ml×3). The extract was washed with water, dried over MgSO4 and concentrated under reduced pressure. The concentrate was purified by silica gel column chromatography (eluent: ethyl acetate) to give the object compound (0.7 g, yield 26.7%) as crystals. m.p. 97° C.

Workup

  1. temperaturewas refluxed for 5 hours
  2. customAfter completion of the reaction
  3. distillationdistilled under reduced pressure
  4. customto remove the solvent
  5. additionThe residue to which saturated sodium hydrogen carbonate aqueous solution (50 ml) was added
  6. extractionwas extracted with chloroform (100 ml×3)
  7. washThe extract was washed with water
  8. dry with materialdried over MgSO4
  9. concentrationconcentrated under reduced pressure
  10. customThe concentrate was purified by silica gel column chromatography (eluent: ethyl acetate)

Sources & evidence

ORD record
ord-117e9f0b65764745badc6d7273b6fe6c
Source dataset
uspto-grants-1996_03
Patent number
US05498774

Reaction notes

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