[Cl:1][C:2]1[N:3]=[N:4][C:5](Cl)=[CH:6][CH:7]=1.[CH:9](B1OC(C)(C)C(C)(C)O1)=[CH2:10].C(=O)([O-])[O-].[K+].[K+].O1CCOCC1>C1C=CC([PH+]([C]2[CH][CH][CH][CH]2)C2C=CC=CC=2)=CC=1.C1C=CC([PH+]([C]2[CH][CH][CH][CH]2)C2C=CC=CC=2)=CC=1.C(Cl)Cl.Cl[Pd]Cl.[Fe].O>[Cl:1][C:2]1[N:3]=[N:4][C:5]([CH:9]=[CH2:10])=[CH:6][CH:7]=1
A mixture of 3,6-dichloropyridazine (6 g, 40.3 mmol), vinyl boronic acid pinacol ester (6.21 g, 6.83 mL, 40.3 mmol), potassium carbonate (120 mmol, 16.7 g), 1,4-dioxane (60 mL) and water (24 mL) was degassed for 15 min with nitrogen gas. Dichloro[1,1′-bis(diphenylphosphino)ferrocene]palladium(II) dichloromethane adduct (0.4 mmol, 292 mg) was then added and the mixture heated to 80° C. for 4 hours. The aqueous phase was then removed via pipette and the organic phase concentrated onto silica gel and purified via flash column chromatography (SiO2, hexane:ethyl acetate 100:0-60:40) to return 3-chloro-6-vinyl-pyridazine as a white solid (5.2 g, 92% yield). 1H NMR (CDCl3) δ 5.75 (1H, d), 6.25 (1H, d), 7.05 (1H, dd), 7.49 (1H, d), 7.59 (1H, d). MS m/z=141 (M+H+)+.
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