4-Bromotoluene → 2-Methyl-6-(4-methylphenyl)pyridine

Participants

Reaction Steps

Magnesium (1.6 g) and p-bromotoluene (10.2 g) in 100 ml of tetrahydrofuran were stirred and warmed until the reaction commenced. When the exothermic reaction had finished, the mixture was refluxed for 1 hour. In a separate flask, a solution of palladium(II)bis(triphenylphosphine)dichloride (1.4 g) in 60 ml of tetrahydrofuran was prepared, and 4 ml of DIBAL (1M in toluene) added, followed by 2-bromopicoline (6.9 g). To this mixture, the magnesium reagent prepared above was added dropwise, causing an exothermic reaction. The reaction mixture was stirred overnight at room temperature, and then quenched by addition of ether/water. The mixture was washed with dilute hydrochloric acid, water, and then saturated brine. The organic layer was separated, dried over sodium sulfate, the solvent evaporated under reduced pressure, and the residue chromatographed on silica gel, eluting with 30-50% methylene chloride in heptane, to yield 4.5 g of 2-(4-methylphenyl)-6-methylpyridine, a compound of Formula (31), as an oil.

Provenance & Evidence