Bromine → 2(4-Dibromomethylphenyl)pyridine

Participants

Reaction Steps

In a 300 ml four neck flask equipped with a water separator were placed 2-(4-tolyl)pyridine (20.0 g, 0.118 mol), chlorobenzene (100 ml) and benzenesulfonic acid monohydrate (20.82 g, 0.118 mol), and the mixture was heated. At around 90° C., water was azeotropically distilled into the water separator. The mixture was further heated while distilling water until the temperature of the distillate reached 131° C. Bromine (26.4 g, 0.165 mol) was added dropwise to this reaction mass at 120-130° C. over 8 hours. The reaction mixture was stirred with heating at a temperature in the above-mentioned range for 4 hours and analyzed by HPLC. As a result, 2-(4-bromomethylphenyl)pyridine was confirmed to have been produced in a 68.89% yield and 2-(4-dibromomethylphenyl)pyridine was confirmed to have been produced in a 19.49% yield. This reaction mass was used as it was in the next reaction. From the 1H-NMR analysis, production of 2-(4-bromomethylphenyl)pyridine benzenesulfonate and 2-(4-dibromomethylphenyl)pyridine benzenesulfonate was confirmed.

Provenance & Evidence