Apraclonidine Hydrochloride: C~9~H~10~Cl~2~N~4~ HCl. Mw: 281.57. (1) 1,4-Benzenediamine, 2,6-dichloro-N^1^-2-imidazolidinylidene-, monohydrochloride; (2) 2-[(4-Amino-2,6-dichlorophenyl)imino]imidazolidine monohydrochloride. CAS-73218-79-8; CAS-66711-21-5 (apraclonidine)(1988).