Benzamidine hydrochloride

613-92-3

1670-14-0

The general procedure for the synthesis of benzylcarbamidine hydrochloride from benzamidoxime was as follows: benzamidoxime (272 g, 2.0 mol, 1.0 eq.), methanol (500 mL), and Raney Ni catalyst (15 g) were added to a 1 L autoclave. A small amount of liquid ammonia was then added and the air in the kettle was displaced three times with nitrogen. Then hydrogen was introduced, the pressure in the kettle was maintained at 2-3 MPa, and the reaction temperature was controlled at 50°C. The reaction was continued until no more hydrogen was absorbed. Upon completion of the reaction, thermal filtration was performed and the filtrate was concentrated to dryness. The residue was cooled to 5 °C, a solid precipitate was precipitated and filtered to obtain gray crude benzylidine hydrochloride. Subsequently, the crude product was dissolved in ethanol (700 mL), heated until completely dissolved, and decolorized by adding activated charcoal and refluxing for 30 minutes. After performing thermal filtration, the filtrate was cooled to 0 °C, filtered to collect the white solid, and finally dried under vacuum at 50 °C to obtain 325 g of white solid benzylcarbamidine hydrochloride in 94.1% yield and 99.6% HPLC purity.