Benzyl Bromide → 2-Benzyl-4,5-dichloro-2,3-dihydropyridazin-3-one

HRID 446890

Reaction equation

HRID 446890 reaction equation
[Cl:1][C:2]1[C:3](=[O:9])[NH:4][N:5]=[CH:6][C:7]=1[Cl:8].C([O-])([O-])=O.[Cs+].[Cs+].[CH2:16](Br)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1>CN(C=O)C>[CH2:16]([N:4]1[C:3](=[O:9])[C:2]([Cl:1])=[C:7]([Cl:8])[CH:6]=[N:5]1)[C:17]1[CH:22]=[CH:21][CH:20]=[CH:19][CH:18]=1

Participants

5

Conditions

Temperature
60 °C

Procedure

To a mixture of 4,5-dichloro-2H-pyridazin-3-one (3.3 g, 20.0 mmol) and Cs2CO3 (9.77 mg, 1.5 eq) were added DMF (15 mL) and benzyl bromide (3.10 mL, 1.3 eq), which was then stirred for 3 h at 60° C. under nitrogen atmosphere. The mixture was concentrated under reduced pressure, and the residue was extracted twice with ethyl acetate (200 mL). The extract was washed with saturated aqueous sodium hydrogen carbonate solution (NaHCO3, 100 mL×2) and aqueous sodium chloride solution, dried (anhydrous Na2SO4), and concentrated under reduced pressure. The residue was separated by column chromatography (10% ethyl acetate-hexane) to give 4.48 g (88%) of the title compound.

Workup

  1. concentrationThe mixture was concentrated under reduced pressure
  2. extractionthe residue was extracted twice with ethyl acetate (200 mL)
  3. washThe extract was washed with saturated aqueous sodium hydrogen carbonate solution (NaHCO3, 100 mL×2) and aqueous sodium chloride solution
  4. dry with materialdried (anhydrous Na2SO4)
  5. concentrationconcentrated under reduced pressure
  6. customThe residue was separated by column chromatography (10% ethyl acetate-hexane)

Sources & evidence

ORD record
ord-9b94d4afb4674eb596256d10c129bba0
Source dataset
uspto-grants-2013_07
Patent number
US08481537B2

Linked notes

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