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

HRID 2046383Notes

Reaction equation

HRID 2046383 reaction equation
[Cl:1][C:2]1[C:3](=[O:9])[NH:4][N:5]=[CH:6][C:7]=1[Cl:8].[CH2:10](Br)[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1.C(=O)([O-])[O-].[K+].[K+]>[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.C(#N)C>[CH2:10]([N:4]1[C:3](=[O:9])[C:2]([Cl:1])=[C:7]([Cl:8])[CH:6]=[N:5]1)[C:11]1[CH:16]=[CH:15][CH:14]=[CH:13][CH:12]=1

Participants

6

Reactant 3

HCID 7498Benzyl BromideHCID 11430Potassium CarbonateHCID 732474,5-Dichloro-3-hydroxypyridazine

Product 1

HCID 7224382-Benzyl-4,5-dichloro-2,3-dihydropyridazin-3-one

Reagents, catalysts & solvents 2

HCID 74236Tetrabutylammonium BromideCatalystHCID 6342AcetonitrileSolvent

Procedure

A stirred mixture of 4,5-dichloropyridazin-3(2H)-one (26.7 g, 160 mmol), benzyl bromide (19.3 mL, 160 mmol), tetrabutylammonium bromide (2.61 g, 8.10 mmol), and potassium carbonate (56.0 g, 405 mmol) in acetonitrile (405 mL) was heated to reflux for 2 h. The mixture was cooled to room temperature, filtered through a fitted glass, concentrated, and purified by flash chromatography to afford the title compound as a white solid. 1H NMR (500 MHz, CD3SOCD3) δ 8.23 (s, 1H); 7.27-7.35 (m, 5H); 5.27 (s, 2H). LRMS (APCI) calc'd for (C11H9Cl2N2O) [M÷H]+, 255.0. found 255.0.

Workup

  1. temperaturewas heated
  2. temperatureto reflux for 2 h
  3. filtrationfiltered through a fitted glass
  4. concentrationconcentrated
  5. custompurified by flash chromatography

Sources & evidence

ORD record
ord-9c6aae117b6a41efbcd1c0df73e7c34e
Source dataset
uspto-grants-2013_11
Patent number
US08592425B2

Reaction notes

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