3(2H)-Pyridazinone, 4,5-dibromo-2-methyl- → 4-Bromo-5-methoxy-2-methylpyridazin-3(2H)-one

HRID 797

Reaction equation

HRID 797 reaction equation
[Br:1][C:2]1[C:3](=[O:10])[N:4]([CH3:9])[N:5]=[CH:6][C:7]=1Br.[CH3:11][O-:12].[Na+]>CO>[Br:1][C:2]1[C:3](=[O:10])[N:4]([CH3:9])[N:5]=[CH:6][C:7]=1[O:12][CH3:11]

Participants

4

Reactant 2

HCID 2030123(2H)-Pyridazinone, 4,5-dibromo-2-methyl-HCID 10942334Sodium Methoxide

Product 1

HCID 106326414-Bromo-5-methoxy-2-methylpyridazin-3(2H)-one

Reagents, catalysts & solvents 1

HCID 887MethanolSolvent2×

Conditions

Temperature
23 °C

Procedure

4,5-Dibromo-2-methyl-3(2H)-pyridazinone (20 g, Maybridge Chemical Company) was cooled in an ice bath and treated successively with methanol (200 mL) and sodium methoxide (12 mL of a 30% solution in methanol). The ice bath was removed and the reaction was allowed to stir at 23° C. for 3 h. The methanol was removed by evaporation at reduced pressure. The residue was partitioned between dichloromethane and water. The organic layer was dried over magnesium sulfate and concentrated to provide the desired product 17 g as a whim solid melting at 146°-147° C. 1 H NMR (CDCl3): 7.7 (1H), 4.0 (3H), 3.8 (3H).

Workup

  1. customThe ice bath was removed
  2. customThe methanol was removed by evaporation at reduced pressure
  3. customThe residue was partitioned between dichloromethane and water
  4. dry with materialThe organic layer was dried over magnesium sulfate
  5. concentrationconcentrated

Sources & evidence

ORD record
ord-9053e57f398646fcad52b73dfd0e8b51
Source dataset
uspto-grants-1998_03
Patent number
US05723411

Linked notes

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