methyl 3-(5-chloro-2-iminopyridin-1(2H)-yl)-2-oxobutanoate hydrobromide → Methyl 6-chloro-3-methylimidazo[1,2-a]pyridine-2-carboxylate

HRID 627698Notes

Reaction equation

HRID 627698 reaction equation
Br.[Cl:2][C:3]1[CH:4]=[CH:5][C:6](=[NH:17])[N:7]([CH:9]([CH3:16])[C:10](=O)[C:11]([O:13][CH3:14])=[O:12])[CH:8]=1>CO.CCOC(C)=O.C([O-])(O)=O.[Na+]>[Cl:2][C:3]1[CH:4]=[CH:5][C:6]2[N:7]([C:9]([CH3:16])=[C:10]([C:11]([O:13][CH3:14])=[O:12])[N:17]=2)[CH:8]=1

Participants

5

Reactant 1

HCID 86728148methyl 3-(5-chloro-2-iminopyridin-1(2H)-yl)-2-oxobutanoate hydrobromide

Product 1

HCID 86715797Methyl 6-chloro-3-methylimidazo[1,2-a]pyridine-2-carboxylateYield 96.2%

Reagents, catalysts & solvents 3

HCID 887MethanolSolventHCID 8857Ethyl AcetateSolventHCID 516892Sodium BicarbonateSolvent

Procedure

A solution of methyl 3-(5-chloro-2-iminopyridin-1(2H)-yl)-2-oxobutanoate hydrobromide (8.51 g, 26.3 mmol) in MeOH (50 mL) was heated to reflux for 16 h, cooled to room temperature, and concentrated to give a white solid. The solid was dissolved in a mixture of EtOAc and saturated NaHCO3, the aqueous phase was discarded and the organic phase was washed with saturated NaHCO3 (1×), water (1×), brine (1×), dried over MgSO4, filtered, and concentrated to give methyl 6-chloro-3-methylimidazo[1,2-a]pyridine-2-carboxylate (5.68 g, 25.3 mmol, 96% yield) as an off white solid.

Workup

  1. temperatureto reflux for 16 h
  2. concentrationconcentrated
  3. customto give a white solid
  4. washthe organic phase was washed with saturated NaHCO3 (1×), water (1×), brine (1×)
  5. dry with materialdried over MgSO4
  6. filtrationfiltered
  7. concentrationconcentrated

Sources & evidence

ORD record
ord-e58a99f016ba4e45828036f35233f0ab
Source dataset
uspto-grants-2016_04
Patent number
US09309263B2

Reaction notes

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