(R)-(+)-2,2′-Bis(diphenylphosphino)-1,1′-binaphthyl (65.9 mg, 106 μmol) was dissolved under heat in toluene (1.5 ml), then cooled to room temperature, and palladium(II) acetate (15.8 mg, 70.6 μmol) was added, followed by stirring for 1 minute. 4-Bromo-2-tert-butyl-7-cyano-5-phenyl-1-benzofuran (I-258) (500 mg, 1.41 mmol), (3S)-3-(dimethylamino)pyrrolidine (215 μl, 1.69 mmol), sodium tert-butoxide (190 mg, 1.98 mmol) and toluene (1.5 ml) were successively put into it, followed by stirring at 80° C. for 14 hours. Water (30 ml) was added to the reaction liquid, the product was extracted with chloroform (50 ml×3). The organic layer was washed with saturated brine (50 ml), dried over anhydrous magnesium sulfate, concentrated under reduced pressure. The residue was purified twice by silica gel column chromatography (chloroform:methanol=200:1) to obtain the entitled compound (180 mg, 33%) as a yellow solid.
