Sulfuric Acid → Ethyl 8-bromo-6-cyanoimidazo[1,2-a]pyridine-3-carboxylate

HRID 931041

Reaction equation

HRID 931041 reaction equation
[NH2:1][C:2]1[C:9]([Br:10])=[CH:8][C:5]([C:6]#[N:7])=[CH:4][N:3]=1.Cl[C:12]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[CH:13][O-].[K+].S(=O)(=O)(O)O.C(=O)(O)[O-].[Na+]>C(O)C>[Br:10][C:9]1[C:2]2[N:3]([C:12]([C:15]([O:17][CH2:18][CH3:19])=[O:16])=[CH:13][N:1]=2)[CH:4]=[C:5]([C:6]#[N:7])[CH:8]=1

Participants

6

Reactant 4

HCID 1118Sulfuric AcidHCID 516892Sodium BicarbonateHCID 14912506-Amino-5-bromopyridine-3-carbonitrileHCID 74089075Potassium 2-chloro-3-ethoxy-3-oxoprop-1-en-1-olate

Product 1

HCID 118378872Ethyl 8-bromo-6-cyanoimidazo[1,2-a]pyridine-3-carboxylateYield 46%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 6-amino-5-bromonicotinonitrile (6.3 g), potassium 2-chloro-3-ethoxy-3-oxoprop-1-en-1-olate (15 g), sulfuric acid (2.2 mL) and ethanol (160 mL) was heated with reflux for 30 hr. To the reaction mixture was added saturated aqueous sodium bicarbonate solution, and the mixture was extracted with ethyl acetate. The extract was dried over anhydrous magnesium sulfate, and the solvent was evaporated under reduced pressure. The residue was purified by silica gel column chromatography (ethyl acetate/hexane) to give the title compound (4.3 g).

Workup

  1. temperaturewas heated
  2. temperaturewith reflux for 30 hr
  3. extractionthe mixture was extracted with ethyl acetate
  4. dry with materialThe extract was dried over anhydrous magnesium sulfate
  5. customthe solvent was evaporated under reduced pressure
  6. customThe residue was purified by silica gel column chromatography (ethyl acetate/hexane)

Sources & evidence

ORD record
ord-2a2c8c3ab2aa495b82ba7df419346a5a
Source dataset
uspto-grants-2016_03
Patent number
US09296746B2

Linked notes

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