Ethane, 2-bromo-1,1-diethoxy- → Methyl imidazo(1,2-a)pyridine-6-carboxylate

HRID 1976774Notes

Reaction equation

HRID 1976774 reaction equation
[CH2:1](OC(OCC)CBr)[CH3:2].C([O-])(O)=O.[Na+].[NH2:15][C:16]1[CH:25]=[CH:24][C:19]([C:20]([O:22][CH3:23])=[O:21])=[CH:18][N:17]=1>Cl.O>[N:15]1[CH:1]=[CH:2][N:17]2[CH:18]=[C:19]([C:20]([O:22][CH3:23])=[O:21])[CH:24]=[CH:25][C:16]=12

Participants

6

Reactant 3

HCID 74852Ethane, 2-bromo-1,1-diethoxy-HCID 516892Sodium BicarbonateHCID 737487Methyl 6-aminonicotinate

Product 1

HCID 2764326Methyl imidazo(1,2-a)pyridine-6-carboxylateYield 88%

Reagents, catalysts & solvents 2

HCID 313Hydrochloric AcidSolventHCID 962WaterSolvent

Procedure

A solution of bromoacetaldehyde diethyl acetal (3.2 mL, 21.3 mmol) in 12M HCl (0.5 mL) and water (23 mL) was heated at 90° C. for 1 hour, cooled to room temperature, treated sequentially with NaHCO3, (1.67 g, 20 mmol) and methyl 6-aminonicotinate (1.10 g, 7.0 mmol), heated at 60° C. for 30 minutes, cooled to room temperature, adjusted to pH 9, and extracted with ethyl acetate. The extract was washed with water, dried (MgSO4), filtered, and concentrated. The concentrate was purified by flash column chromatography with 97.5:2.5 dichloromethane/methanol to provide 1.02 g (88%) of the desired product.

Workup

  1. temperatureheated at 60° C. for 30 minutes
  2. temperaturecooled to room temperature
  3. extractionextracted with ethyl acetate
  4. washThe extract was washed with water
  5. dry with materialdried (MgSO4)
  6. filtrationfiltered
  7. concentrationconcentrated
  8. customThe concentrate was purified by flash column chromatography with 97.5:2.5 dichloromethane/methanol

Sources & evidence

ORD record
ord-f9c93001185843cdbee6c69c1b49fc19
Source dataset
uspto-grants-2001_05
Patent number
US06228868B1

Reaction notes

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