Synthesis
4-Bromotoluene (86.4 mg, 0.5 mmol), phenyltrimethoxysilane (152 mg, 0.75 mmol), PS PdONPs (2.9 mg, 1.5 mol% Pd), TBAC (142 mg, 0.5 mmol), and aq NaOH solution (1.5 M, 1 mL) were added to a screw-capped vial with a stir bar. After stirring at 80°C for 3 h, the vial was immediately immersed in H2O (approximately 20°C) for about 10 min, and the reaction mixture was cooled to rt. After separating the catalyst and aqueous phase by centrifugation, the aqueous phase was decanted. The recovered catalyst was washed with H2O (5 × 3.0 mL) and Et2O (5 × 3.0 mL), and then added to the aqueous phase. The aqueous phase was extracted eight times with Et2O. The combined organic extracts were dried on MgSO4 and concentrated under reduced pressure to give the product 4,4'-dimethylbiphenyl. The product was analyzed by 1H NMR.
Figure 4,4'-dimethylbiphenyl
Uses
4,4'-Dimethylbiphenyl is used in the preparation of biphenyl-4,4-dicarboxylic acid, which acts as a monomer utilized in the synthesis of linear long chain polymer through polycondensation reaction. It is used to prepare 4-(4'-methylphenyl)benzaldehyde by selective photoxygenation reaction using 9-phenyl-10-methylacridinium perchlorate as a catalyst under visible light irradiation.
