2-Amino-1-[3-ethoxy-2,3-dioxo-1-(2-phenylethyl)propyl]pyridinium bromide → Ethyl 3-(2-phenylethyl)imidazo[1,2-a]pyridine-2-carboxylate

HRID 2169007Notes

Reaction equation

HRID 2169007 reaction equation
[Br-].[NH2:2][C:3]1[CH:8]=[CH:7][CH:6]=[CH:5][N+:4]=1[CH:9]([CH2:17][CH2:18][C:19]1[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1)[C:10](=O)[C:11]([O:13][CH2:14][CH3:15])=[O:12]>C(O)C>[C:19]1([CH2:18][CH2:17][C:9]2[N:4]3[CH:5]=[CH:6][CH:7]=[CH:8][C:3]3=[N:2][C:10]=2[C:11]([O:13][CH2:14][CH3:15])=[O:12])[CH:24]=[CH:23][CH:22]=[CH:21][CH:20]=1

Participants

3

Reactant 1

HCID 866422092-Amino-1-[3-ethoxy-2,3-dioxo-1-(2-phenylethyl)propyl]pyridinium bromide

Product 1

HCID 58355694Ethyl 3-(2-phenylethyl)imidazo[1,2-a]pyridine-2-carboxylateYield 93.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of ethyl 3-bromo-2-oxo-5-phenylpentanoate (1.9 g) in THF (10 ml) was added 2-aminopyridine (600 mg) at room temperature, and the reaction mixture was heated under reflux for 15 hr. The precipitated crystals were collected by filtration, washed with THF to give 2-amino-1-[3-ethoxy-2,3-dioxo-1-(2-phenylethyl)propyl]pyridinium bromide (1.36 g). 2-Amino-1-[3-ethoxy-2,3-dioxo-1-(2-phenylethyl)propyl]pyridinium bromide (1.36 g) was dissolved in ethanol (10 ml), and the mixture was refluxed under heating for 3 hr. The reaction mixture was concentrated, and dissolved in dichloromethane. The solution was washed successively with aqueous sodium bicarbonate and saturated brine, and dried over anhydrous sodium sulfate. The solvent was evaporated under reduced pressure. The residue was recrystallized from ethyl acetate-diethyl ether to give the object product (950 mg).

Workup

  1. temperaturethe mixture was refluxed
  2. temperatureunder heating for 3 hr
  3. concentrationThe reaction mixture was concentrated
  4. dissolutiondissolved in dichloromethane
  5. washThe solution was washed successively with aqueous sodium bicarbonate and saturated brine
  6. dry with materialdried over anhydrous sodium sulfate
  7. customThe solvent was evaporated under reduced pressure
  8. customThe residue was recrystallized from ethyl acetate-diethyl ether

Sources & evidence

ORD record
ord-f6ff2660fdf549e697e388c99df968e2
Source dataset
uspto-grants-2015_06
Patent number
US09045436B2

Reaction notes

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