Cl[C:2]1[CH:11]=[CH:10][C:9]2[C:4](=[N:5][CH:6]=[CH:7][C:8]=2[Cl:12])[N:3]=1.C([Sn](CCCC)(CCCC)[C:18]([O:20]CC)=[CH2:19])CCC.Cl.[OH-].[Na+]>O1CCOCC1.C(OCC)(=O)C>[Cl:12][C:8]1[CH:7]=[CH:6][N:5]=[C:4]2[C:9]=1[CH:10]=[CH:11][C:2]([C:18](=[O:20])[CH3:19])=[N:3]2A stirred solution of 2,5-dichloro-[1,8]naphthyridine (Barlin, G. B.; Tan, W.-L. Aust. J. Chem. 1984, 37, 1065) (0.1001 g, 0.503 mmol) in 1,4-dioxane (5 mL) was degassed by bubbling nitrogen through for 15 min. Tetrakis-(triphenylphosphine)palladium(0) (30.0 mg, 0.0259 mmol) and tributyl(1-ethoxyvinyl)tin (0.170 mL, 0.503 mmol) was added and the mixture was heated at 80° C. for 17 h under nitrogen. The mixture was diluted with ethyl acetate (20 mL) and shaken with 2 N aqueous HCl (15 mL) for 1 min. The mixture was adjusted to pH 6 with 4 N aqueous NaOH and the organic layer was separated. The aqueous layer was further extracted with ethyl acetate (2×15 mL), and the combined organic extracts were dried (MgSO4) and evaporated in vacuo. The residue was purified by flash chromatography on silica gel, eluting with 15% EtOAc/CH2Cl2, followed by a further column on silica gel eluting with 50% EtOAc/isohexane, to afford 34.9 mg (34%) of the title compound as a white solid. δH (360 MHz, CDCl3) 2.95 (3H, s), 7.68 (1H, d, J 4.6), 8.33 (1H, d, J 8.4), 8.76 (1H, d, J 8.8), 9.12 (1H, d, J 4.9).
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