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

HRID 600349Notes

Reaction equation

HRID 600349 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-731ebbe088b64a488e3b60e784c658b3
Source dataset
uspto-grants-2011_03
Patent number
US07902194B2

Reaction notes

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