Chloroacetaldehyde → imidazo[1,2-a]pyridine-6-carboxamide

HRID 2232430Notes

Reaction equation

HRID 2232430 reaction equation
[NH2:1][C:2]1[CH:10]=[CH:9][C:5]([C:6]([NH2:8])=[O:7])=[CH:4][N:3]=1.Cl[CH2:12][CH:13]=O.C(=O)([O-])O.[Na+]>C(O)C>[C:6]([C:5]1[CH:9]=[CH:10][C:2]2[N:3]([CH:12]=[CH:13][N:1]=2)[CH:4]=1)(=[O:7])[NH2:8]

Participants

5

Reactant 3

HCID 33ChloroacetaldehydeHCID 95006-AminonicotinamideHCID 516892Sodium Bicarbonate

Product 1

HCID 326954imidazo[1,2-a]pyridine-6-carboxamideYield 29.8%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To 100 ml of ethanol are added 10 g of 6-aminonicotinamide, 11 g of 40% chloroacetaldehyde and 12.5 g of sodium hydrogen carbonate and the mixture is heated under reflux for 4 hours. Ethanol is evaporated off and 100 ml of water is added to the residue. The mixture is adjusted to pH 10 by adding 10% aqueous sodium hydroxide solution and then extracted four times with 50 ml portions of a mixture solvent of tetrahydrofuran-ethyl acetate (1:1). The extracts are combined, dried over anhydrous sodium sulfate and concentrated under reduced pressure. The resulting residue is recrystallized from a mixture solvent of methanol-diethyl ether to give 3.5 g of the above-identified compound as colorless needles.

Workup

  1. temperaturethe mixture is heated
  2. temperatureunder reflux for 4 hours
  3. customEthanol is evaporated off
  4. addition100 ml of water is added to the residue
  5. additionby adding 10% aqueous sodium hydroxide solution
  6. extractionextracted four times with 50 ml portions of a mixture solvent of tetrahydrofuran-ethyl acetate (1:1)
  7. dry with materialdried over anhydrous sodium sulfate
  8. concentrationconcentrated under reduced pressure
  9. customThe resulting residue is recrystallized from a mixture solvent of methanol-diethyl ether

Sources & evidence

ORD record
ord-df77e44bdd6a40f797dd7f50d36022a1
Source dataset
uspto-grants-1988_11
Patent number
US04788185

Reaction notes

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