6,6'-DIBROMO-2,2'-DIPYRIDYL

The 7.15 g 2, 6-dibromopyridine was stirred and dissolved in100 ml diethyl ether under room temperature, followed by addition of 15 ml (2.5 mol/L) n-BuLi drop by drop under -78 °C. Afterthe mixture was stirred under -78 °C for 0.5 h, the temperatureraised naturally to 50 C by stopping cooling, and then decreasedto -78 °C by restarting cooling, followed by adding 4.12 g CuCl2into the mixture. The resulting mixture was transferred into theoxygen atmosphere for 30 min, when reaching to -50 to -60 °C.The reaction was quenched by the addition of a few drops of water, and the liquid phase of the mixture was obtained by suction filtration, dried over Na2SO4, filtered, and evaporated under reducedpressure. After purifying by column chromatography on silica gel, 6, 6'-dibromo-2, 2'-bipyridine was obtained in 30percent yield. 1H NMRin Fig. S1 (400 MHz, CDCl3, TMS) δ 7.50 (2H), 7.65 (2H), 8.37 (2H)ppm; 13C NMR in Fig. S1 (CDCl3, 100 MHz) δ 120.17, 128.60, 139.31, 141.6, 155.62 ppm.General procedure: To an undivided electrochemical cell, fitted by a zinc rod as the anode and surrounded by a nickel foam as the cathode, were added DMF (50 mL), 0.1 M NaI, and 1, 2-dibromoethane (2.5 mmol, 215 μL). The mixture was electrolyzed under argon at a constant current intensity of 0.2 A at room temperature for 15-20 min. Then the current was stopped, and [Ni(bpy)]BrWith the aim of improving the preparation of 6, 6'-dihalo-2, 2'-bipyridines, a different synthesis strategy was envisioned. This synthesis is made up of three steps starting from the 2-chloro-6-methoxypyridine 57; homocoupling of the 2-chloro-6-methoxypyridine 57, followed by hydrolysis of the 6, 6'-methoxy groups of the dimer 58, then halogenation of the bipyridinone 59 obtained (Scheme 26). The 2-chloro-6-methoxypyridine 57 is homocoupled in the presence of a stoichiometric amount of a solution (1:0.3:1) of zinc, NiBrGeneral procedure: The controlled current preparative electrolysis were carried out with a potentiostat/galvanostat equipment. Undivided cells with 20 mL compartment were used. Zn or Fe metallic rod with 8 mm diameter was used as the sacrificial anode. Ni foam (6 cm.x.3.5 cm) was used as the cathode. It could be re-used after washing with a 6 M HCl solution following by water and acetone, and dried. The same solution was used to clean the anode. A 5 mL DMF solution containing 7percent or 20percent of NiBrGeneral procedure: The controlled current preparative electrolysis were carried out with a potentiostat/galvanostat equipment. Undivided cells with 20 mL compartment were used. Zn or Fe metallic rod with 8 mm diameter was used as the sacrificial anode. Ni foam (6 cm.x.3.5 cm) was used as the cathode. It could be re-used after washing with a 6 M HCl solution following by water and acetone, and dried. The same solution was used to clean the anode. A 5 mL DMF solution containing 7percent or 20percent of NiBr

Molecular Weight:313.98
XLogP3:3.5
Hydrogen Bond Acceptor Count:2
Rotatable Bond Count:1
Exact Mass:313.88772
Monoisotopic Mass:311.88977
Topological Polar Surface Area:25.8
Heavy Atom Count:14
Complexity:169
Covalently-Bonded Unit Count:1
Compound Is Canonicalized:Yes