To a solution of 6-trifluoromethylsulfonyloxy-8-(3-nitrophenyl)-1,7-naphthyridine (250 mg, 0.62 mmol prepared according to example 13) in tetrahydrofuran (3 ml) is added vinyltributylstannane (218 mg, 0.68 mmol), bis(dibenzylideneacetone)palladium (14 mg, 0.025 mmol), triphenylphosphine (13 mg, 0.049 mmol) and lithium chloride (78 mg, 1.86 mmol). The mixture is kept at 70° C. overnight. The solution is diluted with ethyl acetate, filtered and washed with water. Preparative thin layer chromatography (8:2 dichloromethane/n-hexane) affords the title compound. Mass M+H 278; mp 145-151° C.
