Cl[C:2]1[N:3]=[N:4][C:5]([O:8][CH3:9])=[CH:6][CH:7]=1>[Br-].C([N+](CCCC)(CCCC)CCCC)CCC.Cl[Ni](Cl)([P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1)[P](C1C=CC=CC=1)(C1C=CC=CC=1)C1C=CC=CC=1.[Zn].CN(C=O)C>[CH3:9][O:8][C:5]1[N:4]=[N:3][C:2]([C:2]2[N:3]=[N:4][C:5]([O:8][CH3:9])=[CH:6][CH:7]=2)=[CH:7][CH:6]=1
In a 100 ml two-necked flask, 1.55 g (2.1 mmol) of dichlorobis(triphenylphosphine)nickel(II), 452 mg (6.95 mmol) of zinc and 2.23 g (6.95 mmol) of tetrabutylammonium bromide are solubilized in 40 ml of freshly distilled DMF. After degassing, the solution is stirred at ambient temperature for 30 min (the green starting solution turns brown). 1 g (6.95 mmol) of 3-chloro-6-methoxypyridazine 14 is added to this solution, and the reaction mixture is heated at 55° C. for 8 hours. After the solvent has been evaporated off under reduced pressure, the residue is taken up in a saturated solution of ammonium chloride, the suspension is extracted with 4×40 ml of dichloromethane and the organic phase is dried over MgSO4 and then concentrated under reduced pressure. The reaction crude is chromatographed on silica gel (eluent:ethyl acetate/petroleum ether=4/6), to give the bipyridazine 15 with a yield of 96%.
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