Ammonium Chloride → 2-(2,3-Dichlorophenyl)-acetamidine hydrochloride

To a stirred suspension of NH4Cl (4.29 g, 80.21 mmol) in dry toluene (120 mL) was added trimethyl aluminium (2M in toluene, 41 mL, 80.21 mmol) at 5° C. The mixture was then warmed to room temperature and stirred for 2 h. A solution of (2,3-dichlorophenyl)-acetonitrile (128) (5 g, 26.73 mmol) in toluene (25 mL) was added to the mixture and 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 filtered through a sintered funnel. The silica gel was washed with methanol and the combined filtrate was concentrated under reduced pressure to get 2-(2,3-dichlorophenyl)-acetamidine hydrochloride salt (129) (5 g, 78%) as an off-white solid.