1,2-Benzenediol, 4-[(4-nitrophenyl)azo]-, 4-(4-nitro-phenylazo)-pyrocatechol, 4-(4-Nitrobenzeneazo) catechol, 4-[(4-nitrophenyl)azo]-1,2-benzenediol, (4-Nitro-benzol)-(1 azo 4)-brenzcatechin, 4-(4-Nitro-phenylazo)-brenzcatechin, 4-(4-Nitrophenylazo)catechol, 4-[(4-nitrophenyl)diazenyl]-1,2-benzenediol, 4'-Nitro-3.4-dioxy-azobenzol