A 1 M solution of Hunig's Base in anhydrous DMF is prepared (Solution A). A 0.5 M solution of 1-H-pyrazole-1-carboxamidine hydrochloride is prepared using solution A. A 0.25 M solution of (3-chlorophenyl)methanamine in anhydrous DMF is prepared. A solution of (3-chlorophenyl)methanamine (800 μL, 200 mmol, 1.0 eq) is added to a solution of 1-H-pyrazole-1-carboxamidine hydrochloride (400 μL, 200 mmol, 1.0 eq) followed by addition of Hunig's Base (80 μL, 2.3 eq). The reaction mixture is heated at 100° C. for 24 hours. The solvent is removed under reduced pressure to give the crude desired product as a viscous oil. The crude product is dried by azeotoping with acetone and drying the residue under high vacuum. The crude 1-(3-chlorobenzyl)guanidinium chloride is used in the next step without any further purification.
