6-Amino-3-chloropyridazine → Ethyl (6-chloroimidazo[1,2-b]pyridazin-2-yl)acetate

HRID 1169119Notes

Reaction equation

HRID 1169119 reaction equation
[NH2:1][C:2]1[N:3]=[N:4][C:5]([Cl:8])=[CH:6][CH:7]=1.Cl[CH2:10][C:11](=O)[CH2:12][C:13]([O:15][CH2:16][CH3:17])=[O:14]>C(O)C>[Cl:8][C:5]1[CH:6]=[CH:7][C:2]2[N:3]([CH:10]=[C:11]([CH2:12][C:13]([O:15][CH2:16][CH3:17])=[O:14])[N:1]=2)[N:4]=1

Participants

4

Reactant 2

HCID 216436-Amino-3-chloropyridazineHCID 69484Ethyl 4-chloroacetoacetate

Product 1

HCID 10331836Ethyl (6-chloroimidazo[1,2-b]pyridazin-2-yl)acetateYield 61.3%

Reagents, catalysts & solvents 1

HCID 702EthanolSolvent

Procedure

11.2 g of 3-amino-6-chloropyridazine was suspended in 150 ml of ethanol; 28.6 g of ethyl 4-chloroacetoacetate was added, followed by heating and refluxing for 24 hours. After cooling, the mixture was concentrated under reduced pressure. The residue was adjusted to pH 7 by the addition of an aqueous solution of sodium hydrogen carbonate, followed by extraction with ethyl acetate; the extract was washed with saline, dried over magnesium sulfate and concentrated under reduced pressure. The residue was subjected to silica gel column chromatography and eluted with hexane:ethyl acetate (2:3). The desired fraction was collected to yield 12.7 g of the title compound.

Workup

  1. temperatureby heating
  2. temperaturerefluxing for 24 hours
  3. temperatureAfter cooling
  4. concentrationthe mixture was concentrated under reduced pressure
  5. additionThe residue was adjusted to pH 7 by the addition of an aqueous solution of sodium hydrogen carbonate
  6. extractionfollowed by extraction with ethyl acetate
  7. washthe extract was washed with saline
  8. dry with materialdried over magnesium sulfate
  9. concentrationconcentrated under reduced pressure
  10. washeluted with hexane:ethyl acetate (2:3)
  11. customThe desired fraction was collected

Sources & evidence

ORD record
ord-8cfa5bf4aa1a4f09ab678b1fb906cae7
Source dataset
uspto-grants-2003_09
Patent number
US06627630B1

Reaction notes

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