21.3 g (0.1 mole) of 1-phenylbiguanide hydrochloride were dissolved in hot
water and the solution was added to 5.3 g (0.05 mole) sodium carbonate by
stirring. On cooling 15 g of the needle crystals have fallen. They were heated
to reflux with 80 ml of dry formic acid. Then 40-50 ml formic acid was distilled
off. The residue was with water diluted, cooled with ice and the conc. alkali
was added. The precipitate fallen. It was filtered off and recrystallized from
40-50% ethanol. The pure product 4-amino-2-anilino-1,3,5-triazine had MP:
232°-233°C.
Monochlorohydrate of it crystallized as long colorless needles melted at 258°-
260°C.
