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

HRID 1070061Notes

Reaction equation

HRID 1070061 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 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 hexane (3:2, v/v)-eluted fraction
  10. customRecrystallization from ethyl acetate-hexane

Sources & evidence

ORD record
ord-e7a35b0c89ff43f49c6644e3371ed6ef
Source dataset
uspto-grants-2001_06
Patent number
US06251926B1

Reaction notes

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