Chloroacetone → IMidazo[1,2-a]pyridine-6-carboxylic acid, 2-Methyl-

HRID 704625Notes

Reaction equation

HRID 704625 reaction equation
[NH2:1][C:2]1[CH:11]=[CH:10][C:5]([C:6]([O:8]C)=[O:7])=[CH:4][N:3]=1.Cl[CH2:13][C:14](=O)[CH3:15]>C(O)C>[CH3:15][C:14]1[N:1]=[C:2]2[CH:11]=[CH:10][C:5]([C:6]([OH:8])=[O:7])=[CH:4][N:3]2[CH:13]=1

Participants

4

Reactant 2

HCID 6571ChloroacetoneHCID 737487Methyl 6-aminonicotinate

Product 1

HCID 20072829IMidazo[1,2-a]pyridine-6-carboxylic acid, 2-Methyl-Yield 71.1%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of methyl 6-aminonicotinate (510 mg), chloroacetone (620 mg) and ethanol (10 ml) was refluxed for 10 hours. After the solvent was removed, ethanol (5 ml) and water (5 ml) was added to the residue. To the solution containing methyl 2-methylimidazo[1,2-a]pyridine-6-carboxylate was added sodium hydroxide (536 mg) and the mixture was stirred for 1 hour at ambient temperature. Ethanol was evaporated and the resulting crystal was collected. A suspension of the obtained crystal in water (3 ml) was adjusted to pH 3.5 with hydrochloric acid, and the residual crystal was collected and dried to give 2-methylimidazo[1,2-a]pyridine-6-carboxylic acid (0.42 g).

Workup

  1. temperaturewas refluxed for 10 hours
  2. customAfter the solvent was removed
  3. additionethanol (5 ml) and water (5 ml) was added to the residue
  4. additionTo the solution containing methyl 2-methylimidazo[1,2-a]pyridine-6-carboxylate
  5. additionwas added sodium hydroxide (536 mg)
  6. customEthanol was evaporated
  7. customthe resulting crystal was collected
  8. additionA suspension of the obtained crystal in water (3 ml)
  9. customthe residual crystal was collected
  10. customdried

Sources & evidence

ORD record
ord-7896027163ec4547906133d568a70462
Source dataset
uspto-grants-1991_01
Patent number
US04988698

Reaction notes

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