Hydrochloric Acid → 3-Chloro-4-methoxyaniline hydrochloride

A stirred mixture of 3.0 grams (0.019 mole) of 90% pure 3-chloro-4-methoxyaniline and 4 mL of concentrated hydrochloric acid in 20 mL of toluene was heated to reflux using a heat gun. The reaction mixture was then concentrated under reduced pressure to a residue. The residue was triturated with 50 mL of diethyl ether, and the resultant solid was collected by filtration. The solid was dried under vacuum, yielding 3.4 grams (0.018 mole) of 3-chloro-4-methoxyaniline hydrochloride. A stirred mixture of the aniline hydrochloride and 1.8 grams (0.022 mole) of cyanoguanidine in 25 mL of acetone was then heated at reflux for about 20 hours. The mixture was cooled, and a solid was collected by filtration. The solid was dried under vacuum, yielding 4.9 grams of 1-(3-chloro-4-methoxyphenyl)-2,4-diamino-6,6-dimethyl-1,6-dihydro-1,3,5-triazine hydrochloride, mp 232 ° C. The NMR spectrum was consistent with the proposed structure.