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

HRID 594049Notes

Reaction equation

HRID 594049 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=O)C.[Cl-].[NH4+]>[Br:1][C:2]1[C:3](=[O:9])[N:4]([CH3:10])[N:5]=[C:6]([Cl:8])[CH:7]=1

Participants

6

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 79%

Reagents, catalysts & solvents 2

HCID 6228DimethylformamideSolventHCID 25517Ammonium ChlorideSolvent

Procedure

To a solution of 4-bromo-6-chloropyridazin-3(2H)-one (1.0 equiv.) and Cs2CO3 (1.2 equiv.) in DMF (0.07 M) was added iodomethane (1.5 equiv.) drop-wise over 20 min. The resulting mixture was stirred for 3 h. The reaction mixture was then diluted with ammonium chloride, then extracted with ethyl acetate, dried over MgSO4 and concentrated in vacuo to yield as a brown solid. The oil was further purified via silica gel column chromatography eluting with 100% heptanes to 80% ethyl acetate:heptanes to yield 4-bromo-6-chloro-2-methylpyridazin-3(2H)-one as an off-white solid in 79% yield. LCMS (m/z) (M+H)=222.9/224.9, Rt=0.54 min. 1H NMR (400 MHz, <cdcl3>) δ ppm 3.77-3.86 (m, 3H) 7.56-7.69 (m, 1H).

Workup

  1. extractionextracted with ethyl acetate
  2. dry with materialdried over MgSO4
  3. concentrationconcentrated in vacuo
  4. customto yield as a brown solid
  5. customThe oil was further purified via silica gel column chromatography
  6. washeluting with 100% heptanes to 80% ethyl acetate

Sources & evidence

ORD record
ord-40830fe354554cbcb0e50784b52b67ad
Source dataset
uspto-grants-2016_01
Patent number
US09242969B2

Reaction notes

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