Potassium Carbonate → 3-(3,5,5,8,8-Pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-4-methoxy-benzaldehyde

Beteiligte Stoffe

Reaktionsschritte

A mixture of 3-bromo-4-methoxybenzaldehyde (19.0 g, 88.4 mmol), (3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl) boronic acid (23.8 g, 97.2 mmol) and potassium carbonate (48.8 g, 353.6 mmol) in 1,2-dimethoxyethane (500 mL) and water (40 mL) was degassed with argon for 60 minutes. Tetrakis(triphenylphosphine)palladium(0) (5.0 g, 4.3 mmol) was added and the mixture heated at reflux under argon for 16 hours. The solution was cooled to room temperature, diluted with ethyl acetate (200 mL) and washed successively with water (100 mL) and brine (100 mL), dried over anhydrous magnesium sulfate, filtered and evaporated. The residue was chromatographed on silica gel (eluent: ethyl acetate/hexane, 1:9) to give 26.8 g of 3-(3,5,5,8,8-pentamethyl-5,6,7,8-tetrahydronaphthalen-2-yl)-4-methoxy-benzaldehyde (90%). 1H NMR (500 MHz; CDCl3): δ 1.26 (s, 6 H); 1.32 (s, 6 H); 1.70 (s, 4 H); 2.08 (s, 3 H); 3.89 (s, 3 H); 7.06 (d, J=8.5 Hz, 1 H); 7.09 (s, 1 H); 7.16 (s, 1H); 7.71 (d, J=2.0 Hz, 1H); 7.88 (dd, J132 2.0 Hz, J2=8.5 Hz 1 H), 9.91 (s, 1 H).

Herkunft & Nachweise