Hydrochloric Acid → 2-Chloro-6-propylimidazo[1,2-b]pyridazine

HRID 969727Notes

Reaction equation

HRID 969727 reaction equation
[Cl:1][C:2]1[N:3]=[C:4]2[CH:9]=[CH:8][C:7](Cl)=[N:6][N:5]2[CH:11]=1.O1C[CH2:15][CH2:14][CH2:13]1.C([Mg]Br)CC.Cl>Cl[Ni](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[Br-].[Zn+2].[Br-].O>[Cl:1][C:2]1[N:3]=[C:4]2[CH:9]=[CH:8][C:7]([CH2:13][CH2:14][CH3:15])=[N:6][N:5]2[CH:11]=1

Participants

8

Reactant 4

HCID 313Hydrochloric AcidHCID 8028Tetrahydrofuran2×HCID 144223582,6-Dichloroimidazo[1,2-b]pyridazineHCID 178455851HCID 178455851, compound

Product 1

HCID 230280952-Chloro-6-propylimidazo[1,2-b]pyridazine

Reagents, catalysts & solvents 3

HCID 10421208Zinc bromideCatalystHCID 178418751HCID 178418751, compoundCatalystHCID 962WaterSolvent

Procedure

Under a nitrogen stream, 2,6-dichloroimidazo[1,2-b]pyridazine (1.00 g, 5.32 mmol), bis(triphenylphosphine)nickel(II) dichloride (0.10 g, 0.16 mmol) and zinc bromide (0.04 g, 0.16 mmol) were added to tetrahydrofuran (8.0 ml), and a solution of n-propylmagnesium bromide in tetrahydrofuran (2 M, 3.99 ml, 7.98 mmol) was added dropwise over 10 minutes to the mixture under ice-cooling. The reaction mixture was stirred for 10 minutes under ice-cooling, and warmed to room temperature and stirred for 4 hours at room temperature. Cold water (100 ml) was added to the reaction mixture which was then acidified with dilute hydrochloric acid, and extracted with ethyl acetate. The extracts were washed with dilute hydrochloric acid, a saturated saline, an aqueous saturated sodium bicarbonate solution and a saturated saline in this order. The resulting organic layer was dried over anhydrous magnesium sulfate, filtrated and concentrated. The concentrated residue was purified by silica gel column chromatography (ethyl acetate:hexane=3:7) to give the title compound as pale yellow crystals. The yield was 0.76 g (73.1%).

Workup

  1. temperaturecooling
  2. temperaturecooling
  3. stirringstirred for 4 hours at room temperature
  4. extractionextracted with ethyl acetate
  5. washThe extracts were washed with dilute hydrochloric acid
  6. dry with materialThe resulting organic layer was dried over anhydrous magnesium sulfate
  7. filtrationfiltrated
  8. concentrationconcentrated
  9. customThe concentrated residue was purified by silica gel column chromatography (ethyl acetate:hexane=3:7)

Sources & evidence

ORD record
ord-8e395717a3d542e7aad7e98a5ba6c586
Source dataset
uspto-grants-2007_12
Patent number
US07307165B2

Reaction notes

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