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

HRID 1006694Notes

Reaction equation

HRID 1006694 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-38a461c60e1d4357bd3b2c6fa6275990
Source dataset
uspto-grants-2004_09
Patent number
US06790960B2

Reaction notes

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