43.5 g morpholine, 41.7 ml concentrated hydrochloric acid, 40 ml of water,
and 42 g dicyandiamide are refluxed for 48 hours, whereupon the reaction
mixture is cooled to +5°C and filtered. The filtrate is evaporated to dryness
and extracted and extracted with boiling ethanol. Yield: 50 g. The formed 4-
morpholinecarboximidoylguanidine hydrochloride is purified by recrystallization
from methanol. The salt may be converted into the base by adding equivalent
of any basic compound (triethylamine, sodium bicarbonate and so on).
In practice it is usually used as hydrochloride.