2,3-Diaminopyridine → 8-Amino-3-acetyl-2-methylimidazo[1,2-a]pyridine

HRID 1369590Notes

Reaction equation

HRID 1369590 reaction equation
[NH2:1][C:2]1[C:7]([NH2:8])=[CH:6][CH:5]=[CH:4][N:3]=1.Cl[CH2:10][C:11]([CH2:13][C:14](=O)[CH3:15])=[O:12]>C(O)C>[NH2:8][C:7]1[C:2]2[N:3]([C:13]([C:11](=[O:12])[CH3:10])=[C:14]([CH3:15])[N:1]=2)[CH:4]=[CH:5][CH:6]=1

Participants

4

Reactant 2

HCID 99562,3-DiaminopyridineHCID 144968561-Chloro-2,4-pentanedione

Product 1

HCID 226726498-Amino-3-acetyl-2-methylimidazo[1,2-a]pyridineYield 15.7%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

A mixture of 2,3-diaminopyridine (7 g, 64.1 mmol), 3-chloroacetylacetone (8.6 g, 64.1 mmol) in ethyl alcohol (80 ml) was refluxed for 9 hours. The solvent was removed under reduced pressure and the residue dissolved in methylene chloride. A sodium bicarbonate solution was added and the organic layer was separated. The aqueous layer was extracted twice with methylene chloride. The combined organic layer was dried and evaporated under reduced pressure. Chromatography of the residue on silica gel (methylene chloride:methanol, 100:5) gave a product which after recrystallisation from ethyl acetate gave 1.9 g (15%) of the title compound.

Workup

  1. temperaturewas refluxed for 9 hours
  2. customThe solvent was removed under reduced pressure
  3. dissolutionthe residue dissolved in methylene chloride
  4. additionA sodium bicarbonate solution was added
  5. customthe organic layer was separated
  6. extractionThe aqueous layer was extracted twice with methylene chloride
  7. customThe combined organic layer was dried
  8. customevaporated under reduced pressure
  9. customChromatography of the residue on silica gel (methylene chloride:methanol, 100:5) gave a product which
  10. customafter recrystallisation from ethyl acetate

Sources & evidence

ORD record
ord-62a830e6968d496f98dd9d82bae208f6
Source dataset
uspto-grants-2003_06
Patent number
US06579884B1

Reaction notes

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