97674-02-7

179897-89-3

288309-07-9

Under argon protection, 449 mg (0.490 mmol) of tris(dibenzylideneacetone)dipalladium and 671 mg (1.078 mmol) of rac-1,1'-binaphthyl-2,2'-diylbis(diphenylphosphine) were dissolved in 180 mL of toluene with 1.90 g (24.5 mmol) of 3-bromo-6-fluorobenzonitrile. Subsequently 10.6 g (29.4 mmol) of (1-ethoxyvinyl)tributylstannane was added and the reaction mixture was stirred overnight under reflux conditions. Upon completion of the reaction, the mixture was concentrated and the residue was dissolved in 200 mL of tetrahydrofuran. 50 mL of aqueous 2N hydrochloric acid was added and stirred for 4 hours at room temperature. The reaction mixture was neutralized with saturated aqueous sodium bicarbonate and extracted with ethyl acetate. The organic phases were combined, dried with magnesium sulfate, filtered and concentrated under reduced pressure. The crude product was purified by fast column chromatography (eluent: cyclohexane/ethyl acetate, 10:1→3:1) to give 3.50 g (88% yield) of 2-fluoro-5-acetylbenzonitrile. The product was characterized as follows: 1H-NMR (400 MHz, DMSO-d6): δ = 8.55 (dd, 1H), 8.31 (ddd, 1H), 7.68 (t, 1H), 2.63 (s, 3H). gC-MS (Method 11): Rt = 4.34 min; MS (EIpos): m/z = 163 [M]+.