4-Bromotoluene → Ethyl (E)-4-[2-(5,6-dihydro-5,5-dimethyl-8-(4-methylphenyl)-2-naphthalenyl)ethenyl]-benzoate

Beteiligte Stoffe

Reaktionsschritte

A solution of 4-lithiotoluene was prepared at −78° C. by the addition of 130.7 mg of t-butyllithium (2.04 mmol; 1.20 ml of a 1.7M solution in pentane) to a solution of 374.5 mg ( 2.20 mmol) of 4-bromotoluene in 2.5 ml of THF. After 30 minutes a solution of 313.4 mg (2.30 mmol) of ZnCl2 in 2.0 ml of THF was added. The resulting solution was warmed to room temperature, stirred for 1.25 hour and then added via canula to a solution of 285.0 mg (0.590 mmol) of ethyl (E)4-[2-(5,6-dihydro-5,5-dimethyl-8-(trifluoromethylsulfonyl)oxy-2-naphthalenyl)ethenyl]-benzoate (Compound P) and 29.0 mg (0.025 mmol) of tetrakis(triphenylphosphine)palladium(0) in 2.0 ml of THF. The resulting solution was stirred at room temperature for 1 hour and then at 55° C. for 2 hours. Upon cooling to room temperature the reaction was quenched by the addition of saturated aqueous NH4Cl. The mixture was extracted with EtOAc, and the combined extracts were washed with 5% aqueous NaOH, saturated aqueous NaCl, and dried over Na2SO4 before being concentrated under reduced pressure. The title compound was isolated by column chromatography (10% EtOAC / hexanes) as a colorless solid. 1H NMR (CDCl3): δ 7.96 (2H, d, J=8.1 Hz), 7.47 (2H, d, J=8.1 Hz), 7.43-7.16 (7H, m), 7.07 (1H, d, J=16.3 Hz), 6.93 (1H, d, J=16.3 Hz), 5.97 (1H, t, J=4.7 Hz), 4.39 (2H, q, J=7.0 Hz), 2.41 (3H, s), 2.33 (1H, d, J=4.7 Hz), 1.38 (3H, t, J=7.0 Hz), 1.33 (6H, s).

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