1H-Pyrazole-3-carboxylic acid, 4,5-dihydro-4-((3-methylphenyl)azo)-5-oxo- 4,5-Dihydro-5-oxo-4-((m-tolyl)azo)-1H-pyrazole-3-carboxylic acid 5-Oxo-4-(m-tolylazo)-2-pyrazolin-3-carboxylic acid 66256-72-2 EINECS 266-280-3