Chloroacetaldehyde → 7-Chloroimidazo(1,2-a)pyridine

HRID 2400318Notes

Reaction equation

HRID 2400318 reaction equation
[Cl:1][C:2]1[CH:7]=[CH:6][N:5]=[C:4]([NH2:8])[CH:3]=1.C([O-])(O)=O.[Na+].Cl[CH2:15][CH:16]=O>CCO>[Cl:1][C:2]1[CH:7]=[CH:6][N:5]2[CH:15]=[CH:16][N:8]=[C:4]2[CH:3]=1

Participants

5

Reactant 3

HCID 33ChloroacetaldehydeHCID 516892Sodium BicarbonateHCID 5818662-Amino-4-chloropyridine

Product 1

HCID 196959017-Chloroimidazo(1,2-a)pyridineYield 86.5%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

To a solution of 4-Chloro-pyridin-2-ylamine (12.8 g, 100 mmol, 1.0 equiv) in EtOH (170 ml) was added NaHCO3 (16.8 g, 200 mmol, 2.0 equiv) followed by chloroacetaldehyde (19.0 ml, 150 mmol, 1.5 equiv). The mixture was refluxed for 6 h. Solvents removed under reduced pressure and the crude mixture was partitioned between water and EtOAc. The organic layer was washed with brine, dried (MgSO4), filtered and concentrated under reduced pressure. The product was purified by column chromatography (SiO2, eluted with 50% EtOAC-petrol) to afford 13.2 g of product. MS: [M+H]+=153.

Workup

  1. temperatureThe mixture was refluxed for 6 h
  2. customSolvents removed under reduced pressure
  3. customthe crude mixture was partitioned between water and EtOAc
  4. washThe organic layer was washed with brine
  5. dry with materialdried (MgSO4)
  6. filtrationfiltered
  7. concentrationconcentrated under reduced pressure
  8. customThe product was purified by column chromatography (SiO2, eluted with 50% EtOAC-petrol)

Sources & evidence

ORD record
ord-874cb5cfab4d4d2e8a4fa92c7fae1fd6
Source dataset
uspto-grants-2014_08
Patent number
US08796244B2

Reaction notes

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