2-Amino-5-bromopyridine → Ethyl 6-bromoimidazo[1,2-a]pyridine-2-carboxylate

HRID 2065528Notes

Reaction equation

HRID 2065528 reaction equation
C([CH:3](Br)[C:4](=O)[C:5]([O-:7])=[O:6])C.[Br:10][C:11]1[CH:12]=[CH:13][C:14]([NH2:17])=[N:15][CH:16]=1.Cl[CH2:19][CH2:20]Cl.C(O)C>C(O)C>[CH2:19]([O:7][C:5]([C:4]1[N:17]=[C:14]2[CH:13]=[CH:12][C:11]([Br:10])=[CH:16][N:15]2[CH:3]=1)=[O:6])[CH3:20]

Participants

5

Reactant 3

HCID 706222-Amino-5-bromopyridineHCID 21948992EthylbromopyruvateHCID 229016121,2-Dichloroethane ethanol

Product 1

HCID 7141939Ethyl 6-bromoimidazo[1,2-a]pyridine-2-carboxylate

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

Ethylbromopyruvate (62.0 g; 318 mmol; 40.0 ml) was added to a solution of 5-bromo-2-aminopyridine (50.0 g; 289 mmol) in ethanol (500 ml) through a dropping funnel. The reaction batch was first stirred for 30 min at room temperature and then refluxed for 8 hours while stirring (DC control: DCE-ethanol 5:1). The solvent was removed under vacuum and the residue taken up in DCM. It was washed first with saturated common salt solution and then with saturated sodium hydrogen carbonate solution. The organic phase was dried over magnesium sulfate, filtered and concentrated to dryness. The residue was recrystallized from dry diethyl ether. Yield: 41 g (53%)

Workup

  1. temperaturerefluxed for 8 hours
  2. customThe solvent was removed under vacuum
  3. washIt was washed first with saturated common salt solution
  4. dry with materialThe organic phase was dried over magnesium sulfate
  5. filtrationfiltered
  6. concentrationconcentrated to dryness
  7. customThe residue was recrystallized from dry diethyl ether

Sources & evidence

ORD record
ord-c35a35bae8d64c05bdaad7ce3ea9ffdb
Source dataset
uspto-grants-2012_10
Patent number
US08288424B2

Reaction notes

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