6-Amino-3-chloropyridazine → Imidazo(1,2-b)pyridazine, 6-chloro-

HRID 2370039Notes

Reaction equation

HRID 2370039 reaction equation
[NH2:1][C:2]1[N:3]=[N:4][C:5]([Cl:8])=[CH:6][CH:7]=1.Br[CH2:10][CH:11]=O>C(O)CCC>[Cl:8][C:5]1[CH:6]=[CH:7][C:2]2[N:3]([CH:10]=[CH:11][N:1]=2)[N:4]=1

Participants

4

Reactant 2

HCID 216436-Amino-3-chloropyridazineHCID 105131Acetaldehyde, bromo-

Product 1

HCID 138828Imidazo(1,2-b)pyridazine, 6-chloro-Yield 40%

Reagents, catalysts & solvents 1

HCID 2631-ButanolSolvent

Conditions

Temperature
0 °C

Procedure

3-Amino-6-chloro pyridazine (1.5 g, 0.0116 mol) was dissolved in n-butanol (12 ml), cooled to 0° C. and bromoacetaldehyde (2.8 g, 0.023 mol) was added. The reaction was refluxed for 20 hrs and n-butanol was removed under reduced pressure. To the reaction mixture, water was added and extracted with EtOAc (5×20 ml). The combined organic layers were dried (Na2SO4), concentrated under reduced pressure and the residue was purified by column chromatography (EtOAc/hexane) to give 6-Chloro-imidazo[1,2-b]pyridazine (4) (690 mg, yield=40%).

Workup

  1. temperatureThe reaction was refluxed for 20 hrs
  2. customn-butanol was removed under reduced pressure
  3. additionTo the reaction mixture, water was added
  4. extractionextracted with EtOAc (5×20 ml)
  5. dry with materialThe combined organic layers were dried (Na2SO4)
  6. concentrationconcentrated under reduced pressure
  7. customthe residue was purified by column chromatography (EtOAc/hexane)

Sources & evidence

ORD record
ord-94f0f63d1c02421d855dc7da636aaaf0
Source dataset
uspto-grants-2014_04
Patent number
US08710057B2

Reaction notes

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