2-Oxo-2H-1-benzopyran-6-carboxaldehyde (p-nitrobenzoyl)hydrazone 2H-1-Benzopyran-6-carboxaldehyde, 2-oxo-, (p-nitrobenzoyl)hydrazone 6-Formyl-1,2-benzpyrone p-nitrobenzoyl hydrazone DJ2250800