4-Pyridinecarboxylic acid, [(4-hydroxyphenyl)methylene]hydrazide 840-81-3 Flavoteben Isonicotinic acid, (p-hydroxybenzylidene)hydrazide Isonicotinoyl-p-hydroxybenzalhydrazone NSC176757 p-Hydroxybenzaldehyde isonicotinoylhydrazone p-Hydroxybenzalisonicotinic acid, hydrazone p-Oxyberon