Ammonium Chloride → 2-(2'-Chloro-biphenyl-2-yl)-acetamidine hydrochloride salt

To a stirred suspension of NH4Cl (1.4 g, 26.43 mmol) in dry toluene (40 mL) was added tri-methyl aluminium (2M in toluene, 13.2 mL, 26.43 mmol) at 5° C. The reaction mixture was then warmed to room temperature and stirred for 2 h. A solution of (2′-chloro-biphenyl-2-yl)-acetonitrile (15) (2 g, 8.8 mmol) in toluene (10 mL) was added to the reaction mixture, which was then stirred for 14 h at 80° C. After completion of the reaction, it was quenched with a suspension of silica gel in chloroform and the reaction mixture was stirred for half an hour at room temperature and then filtered through a sintered funnel. The silica gel was washed with methanol and the combined filtrates were concentrated under reduced pressure to get 2-(2′-chloro-biphenyl-2-yl)-acetamidine hydrochloride salt as a crude product (5-02) (2 g, 80.97%) as a white solid.