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

Beteiligte Stoffe

Reaktionsschritte

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%).

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