3,3'-Dimethylbenzidine dihydrochloride 3,3'-Dimethylbenzidine hydrochloride 612-82-8 Benzidine, 3,3'-dimethyl-, dihydrochloride NSC11223 [1,1'-Biphenyl]-4,4'-diamine, 3,3'-dimethyl-, dihydrochloride