1-(2,4,6-Trichlorophenyl)-3-(4-nitroanilino)-2-pyrazolin-5-one 1-(2,4,6-Trichlorophenyl)-3-p-nitroanilino-2-pyrazolin-5-one 2-Pyrazolin-5-one, 3-(p-nitroanilino)-1-(2,4,6-trichlorophenyl)- 34320-82-6 3H-Pyrazol-3-one, 2,4-dihydro-5-[(4-nitrophenyl)amino]-2-(2,4,6-trichlorophenyl)- NSC166498