1-Methylpiperazine → 4-Chloro-2-methyl-5-(4-methylpiperazin-1-yl)pyridazin-3(2H)-one

HRID 42704Notes

Reaction equation

HRID 42704 reaction equation
[Cl:1][C:2]1[C:3](=[O:10])[N:4]([CH3:9])[N:5]=[CH:6][C:7]=1Cl.[CH3:11][N:12]1[CH2:17][CH2:16][NH:15][CH2:14][CH2:13]1>O>[Cl:1][C:2]1[C:3](=[O:10])[N:4]([CH3:9])[N:5]=[CH:6][C:7]=1[N:15]1[CH2:16][CH2:17][N:12]([CH3:11])[CH2:13][CH2:14]1

Participants

4

Reactant 2

HCID 531671-MethylpiperazineHCID 1204623(2H)-Pyridazinone, 4,5-dichloro-2-methyl-

Product 1

HCID 170880204-Chloro-2-methyl-5-(4-methylpiperazin-1-yl)pyridazin-3(2H)-one

Reagents, catalysts & solvents 1

HCID 962WaterSolvent

Procedure

A mixture of 4,5-dichloro-2-methylpyridazin-3(2H)-one [S.-F. Chen and R. P. Panzica, J. Org. Chem., 46, 2467-2473 (1981)] (8.95 g, 50 mmol) and 1-methylpiperazine (12.5 g, 125 mmol) in water (150 ml) was refluxed for 30 h. After cooling, about two thirds of the solvent was removed under reduced pressure and the mixture was adjusted to pH 7-8 by addition of aqueous NaHCO3. It was then extracted with dichloromethane (4×40 ml) and the combined extracts were washed with water, dried (Na2SO4) and evaporated. The crude product was purified by recrystallization from ethanol (95%).

Workup

  1. temperaturewas refluxed for 30 h
  2. temperatureAfter cooling, about two thirds of the solvent
  3. customwas removed under reduced pressure
  4. additionthe mixture was adjusted to pH 7-8 by addition of aqueous NaHCO3
  5. extractionIt was then extracted with dichloromethane (4×40 ml)
  6. washthe combined extracts were washed with water
  7. dry with materialdried (Na2SO4)
  8. customevaporated
  9. customThe crude product was purified by recrystallization from ethanol (95%)

Sources & evidence

ORD record
ord-ca1ad0af93bd4ccb9e9e69a7dbd1a515
Source dataset
uspto-grants-2013_09
Patent number
US08536210B2

Reaction notes

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