n-butyllithium in tetrahydrofuran; hexane (Ar, Schlenk) n-C4H9Li in hexane was added to the soln. of bipyridine-compound and borate at -78°C over 25 min, stirred for 30 min, allowed to warm to -20°C followed by addn. of 1 N HCl soln., room temp.; extd. with ethyl acetate, the aq. layer was collected, pH 7 (aq. NaOH), the solid was filtered, washed with CH3CN, dried in vac.; elem. anal.;

1: n-butyllithium; 4-bromo-2,2'-bpy in diethyl ether; hexane T=-110 - -100°C; Metallation; 0.5 h; 2: boric acid trimethyl ester in diethyl ether; hexane T=-110 - -100°C; Substitution; 1 h;

1.1: 50 percent / PBr3 / CHCl3 / 4 h / reflux 2.1: diethyl ether; hexane / 0.5 h / -110 - -100 °C 2.2: 52 percent / diethyl ether; hexane / 1 h / -110 - -100 °C View Scheme

1.1: 89 percent / Acetyl bromide / acetic acid / 9 h / reflux 2.1: 50 percent / PBr3 / CHCl3 / 4 h / reflux 3.1: diethyl ether; hexane / 0.5 h / -110 - -100 °C 3.2: 52 percent / diethyl ether; hexane / 1 h / -110 - -100 °C View Scheme