2-Aminopyridine → 2-Chloromethyl-imidazo(1,2-A)pyridine

HRID 584377Notes

Reaction equation

HRID 584377 reaction equation
[NH2:1][C:2]1[CH:7]=[CH:6][CH:5]=[CH:4][N:3]=1.[Cl:8][CH2:9][C:10](=O)[CH2:11]Cl>C(#N)C>[Cl:8][CH2:9][C:10]1[N:1]=[C:2]2[CH:7]=[CH:6][CH:5]=[CH:4][N:3]2[CH:11]=1

Participants

4

Reactant 2

HCID 104392-AminopyridineHCID 107931,3-Dichloroacetone

Product 1

HCID 9576142-Chloromethyl-imidazo(1,2-A)pyridineYield 34%

Reagents, catalysts & solvents 1

HCID 6342AcetonitrileSolvent

Procedure

A mixture of 2-aminopyridine (12.5 g), 1,3-dichloro-2-propanone (17.7 g) and acetonitrile (100 ml) was heated under reflux for 2 hours and concentrated. An aqueous saturated solution of sodium bicarbonate was added to the residue and extracted with ethyl acetate. The ethyl acetate layer was washed with an aqueous saturated solution of sodium chloride, dried (MgSO4) and concentrated. The residue was subjected to silica gel chromatography to obtain crystals from an ethyl acetate-hexane (3:2, v/v)-eluted fraction. Recrystallization from ethyl acetate-hexane gave 2-chloromethylimidazo[1,2-a]pyridine (7.52 g, yield 34%) as pale-yellow crystals. m.p. 93-94° C.

Workup

  1. temperaturewas heated
  2. temperatureunder reflux for 2 hours
  3. concentrationconcentrated
  4. additionAn aqueous saturated solution of sodium bicarbonate was added to the residue
  5. extractionextracted with ethyl acetate
  6. washThe ethyl acetate layer was washed with an aqueous saturated solution of sodium chloride
  7. dry with materialdried (MgSO4)
  8. concentrationconcentrated
  9. customto obtain crystals from an ethyl acetate-hexane (3:2, v/v)-eluted fraction
  10. customRecrystallization from ethyl acetate-hexane

Sources & evidence

ORD record
ord-9e398ce4a93e48f8a40c8bd6c3131c00
Source dataset
uspto-grants-2005_08
Patent number
US06924300B2

Reaction notes

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