反应详情

To a solution of 546 g (2.74 mol) of trimethyltin chloride in tetrahydrofuran (4 L) under nitrogen at -10° C. was added dropwise, maintaining the temperature below -5° C. over 4 hours, 4.14 L of 1.0 M p-tolylmagnesium bromide in diethyl ether (4.14 mol, 1.5 eq.). The suspension was allowed to warm slowly to room temperature over 12 hours then saturated ammonium chloride solution (1 L) was added followed by sufficient water (approximately 1 L) to dissolve the precipitate. The solution was extracted with ether-hexane (1:1) (1×4 L, 3×2 L). The combined organic phases were washed with brine, dried over magnesium sulfate and the solvents removed under vacuum. Purification by flash chromatography on silica gel eluting with hexanethyl acetate (95:5) gave a pale yellow oil containing white crystals of 4,4'-dimethylbiphenyl which were removed by filtration to leave 698 g (100%) of product. 1H NMR (300 MHz, CDCl3): δ 0.30 (s, 9H), 2.34 (s, 3H), 7.19 (d, 7.7 Hz, 2H), 7.40 (d, 7.7 Hz, 2H).

1. temperaturemaintaining the temperature below -5° C. over 4 hours
2. dissolutionto dissolve the precipitate
3. extractionThe solution was extracted with ether-hexane (1:1) (1×4 L, 3×2 L)
4. washThe combined organic phases were washed with brine
5. dry with materialdried over magnesium sulfate
6. customthe solvents removed under vacuum
7. customPurification by flash chromatography on silica gel eluting with hexanethyl acetate (95:5)
8. customgave a pale yellow oil
9. customwere removed by filtration