Methyl iodide → 4-Bromo-6-chloro-2-methyl-2,3-dihydropyridazin-3-one

HRID 2069781Notes

Reaction equation

HRID 2069781 reaction equation
[Br:1][C:2]1[C:3](=[O:9])[NH:4][N:5]=[C:6]([Cl:8])[CH:7]=1.[C:10](=O)([O-])[O-].[Cs+].[Cs+].IC>CN(C)C=O>[Br:1][C:2]1[C:3](=[O:9])[N:4]([CH3:10])[N:5]=[C:6]([Cl:8])[CH:7]=1

Participants

5

Reactant 3

HCID 6328Methyl iodideHCID 10796Cesium carbonateHCID 115865224-Bromo-6-chloro-2,3-dihydropyridazin-3-one

Product 1

HCID 592164744-Bromo-6-chloro-2-methyl-2,3-dihydropyridazin-3-oneYield 97.5%

Reagents, catalysts & solvents 1

HCID 6228DimethylformamideSolvent

Procedure

4-Bromo-6-chloro-2H-pyridazin-3-one (5.02 g, 23.97 mmol) was dissolved in 40 ml dimethylformamide. Cesium carbonate (9.37 g, 28.76 mmol) was added. After 5 min, iodomethane (5.103 g, 35.95 mmol) was added dropwise over 20 min. The reaction mixture was stirred 3 hours at room temperature. The precipitate was filtered off and concentrated and the resulting residue was treated with 20 ml dichloromethane. The insoluble material was filtered off again and washed with dichloromethane. The filtrate was concentrated in vacuo to yield 4-Bromo-6-chloro-2-methyl-2H-pyridazine-3-one (5.223 g, 23.37 mmol). MS (ESI) 224.9 (M+H)+

Workup

  1. filtrationThe precipitate was filtered off
  2. concentrationconcentrated
  3. additionthe resulting residue was treated with 20 ml dichloromethane
  4. filtrationThe insoluble material was filtered off again
  5. washwashed with dichloromethane
  6. concentrationThe filtrate was concentrated in vacuo

Sources & evidence

ORD record
ord-10af37e77e5a4bf886e2d0c94f1a5765
Source dataset
uspto-grants-2012_10
Patent number
US08299077B2

Reaction notes

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