The general procedure for the synthesis of cyclopropanecarboxamidine hydrochloride from cyclopropanecarbonitrile is as follows: in a 1 L reactor equipped with thermocouples, underground gas feed lines, hydrogen chloride cylinders, cylinder balancing device, and a nitrogen bubbler, the reactor was first flushed with nitrogen. Cyclopropanecarbonitrile (100 g, 1.5 mol), methanol (48 g, 1.5 mol) and toluene (400 mL) were then added. The reaction mixture was maintained at 15 °C under slight positive nitrogen pressure while anhydrous hydrogen chloride (57 g, 1.55 mol) was slowly added under the surface of the reaction mixture over a period of 2 hours. After addition, the reaction mixture was stirred at 23°C for 16 hours. Nitrogen was bubbled through the reaction mixture below the surface to purge the excess hydrogen chloride while the effluent was expelled through a water scrubber, a process that lasted for 2 hours. The mixture was cooled to 5 °C and then a methanol solution of ammonia (240 mL 7M solution, 1.7 mol) was added over 10 min, during which the temperature was kept below 25 °C. After standing for 1 h, the excess methanol was removed by distillation under reduced pressure. The product obtained was filtered and washed with toluene (100 mL) and finally dried by suction to give 170 g (94% yield) of cyclopropanecarboxamidine hydrochloride as a solid. The 1H NMR (DMSO-J6) data of the product were as follows: δ 8.8 (br s, 4H), 1.84 (m, 1H), 1.1 (m, 4H).
