1-(6-Chloronaphth-2-ylsulphonyl)-4-(4-iodobenzoyl)piperazine (920 mg, 1.7 mmol), diethyl 3-pyridylborane (250 mg, 1.7 mmol), tetrabutyl ammonium bromide (110 mg, 0.34 mmol), tetrakis(triphenylphosphine) palladium (0) (69 mg,0.06 mmol) and potassium hydroxide (286 mg, 5.1 mmol) were refluxed in dry tetrahydrofuran (100 mL) for two hours under an atmosphere of nitrogen. The reaction mixture was allowed to cool to room temperature then concentrated in vacuo. The resulting solid was subjected to flash chromatography (SiO2: 100% CH2Cl2, 50% EtOAc/Hexane, 100% EtOAc) to yield an oil. The oil was dissolved in EtOAc (100 mL) and washed with saturated sodium hydrogen carbonate solution (100 mL). The EtOAc layer was separated, dried over MgSO4, filtered and concentrated in vacuo to yield an off white foam which was triturated with hexane. This solid was subjected to chromatography (SiO2: 40%, 50%, 60%, 70% EtOAc/Hexane) to yield 1-(6-chloronaphth-2-ylsulphonyl)-4-[4-(3-pyridyl)benzoyl]piperazine as a white solid (322.4 mg); 1H NMR (DMSO-d6) δ=3.1 ppm (s,4H), δ=3.6 ppm (s,4H), δ=7.46 ppm (d,2H), δ=7.5 to 7.67 ppm (m,1H), δ=7.70 to 7.79 ppm (m,3H), δ=7.83 ppm (dd,1H), δ=8.09 ppm (dt,1H), δ=8.15 ppm to 8.31 ppm (m,3H), δ=8.50 ppm (s,1H), δ=8.60 ppm (dd,1H), δ=8.90 ppm (d,1H); MS (M+H)+ 492.
