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

HRID 1169151Notes

Reaction equation

HRID 1169151 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

After 11.2 g of 3-amino-6-chloropyridazine was suspended in 150 mL of ethanol, 28.6 g of ethyl 4-chloroacetoacetate was added thereto and heated under reflux for 24 hours. After cooling, the mixture was concentrated under reduced pressure and the residue was adjusted to pH 7 by the addition of an aqueous sodium hydrogencarbonate solution and extracted with ethyl acetate. The extract was washed with a saline solution and dried over magnesium sulfate. After concentration under reduced pressure. The residue was subjected to silica gel chromatography to be eluted with hexane:ethyl acetate (2:3). The desired fraction was collected to provide 12.7 g of the title compound.

Workup

  1. temperatureheated
  2. temperatureunder reflux 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 sodium hydrogencarbonate solution
  6. extractionextracted with ethyl acetate
  7. washThe extract was washed with a saline solution
  8. dry with materialdried over magnesium sulfate
  9. concentrationAfter concentration under reduced pressure
  10. washto be eluted with hexane:ethyl acetate (2:3)
  11. customThe desired fraction was collected

Sources & evidence

ORD record
ord-9b085a5e6ed64307a9d8d278cd0d55de
Source dataset
uspto-grants-2003_09
Patent number
US06627630B1

Reaction notes

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