Synonyms: Benzidine,N,N'-diphenyl- (6CI,7CI,8CI);[1,1'-Biphenyl]-4,4'-diamine, N,N'-diphenyl-(9CI);4,4'-Bis(phenylamino)-1,1'-biphenyl;4,4'-Bis(phenylamino)biphenyl;N,N'-Diphenyl-[1,1'-biphenyl]-4,4'-diamine;N,N'-Diphenyl-p,p'-biphenylenediamine;[1,1'-Biphenyl]-4,4'-diamine,N4,N4'-diphenyl-;