2-Bromo-5-methylpyridine → 5-Methyl-[2,2']bipyridinyl

Participants

Reaction Steps

A solution of 2-(tributyltin)pyridine (9.20 g, 25 mmol) and 2-bromo-5-methylpyridine (4.3 g, 25 mmol) in toluene was bubbled with argon gas for 10 min. The catalyst Pd(PPh3)4 (0.29 g, 0.25 mmol, 1 mol %) was added and the mixture was refluxed under argon atmosphere for 3 days. Removal of solvent gave an oil that was purified by chromatography over silica gel eluted with CH2Cl2 and then EtOAc. The brown liquid obtained was dried overnight under high vacuum providing 4.1073 g of 5-methyl-[2,2′]bipyridinyl as a brown liquid (24.13 mmol, yield 96.5%). 1H NMR (CDCl3, 300.16 MHz) δ (ppm) 8.66 (ddd, J=4.8, 1.8 & 0.9 Hz, 1H), 8.51 (dt, J=2.9 & 0.7 Hz, 1H), 8.35 (dt, J=8.0 & 1.1 Hz, 1H), 8.28 (d, J=8.1 Hz, 1H), 7.80 (td, J=7.7 & 1.8 Hz, 1H), 7.63 (ddd, J=8.1, 1.5 & 0.7 Hz, 1H), 7.28 (ddd, J=7.5, 4.8 & 1.2 Hz, 1H) and 2.39 (s, 3H). MS (ESI) m/z: 171 (M+1)+ and (2M+23)+.

Provenance & Evidence