The molecule is a 4,5-dihydropyrazole having p-sulfophenyl-, carboxy-, amino- and oxo substituents at the 1-, 3-, 4- and 5-positions respectively. It is a member of pyrazoles, a monocarboxylic acid, a sulfonic acid and an amino acid. It derives from an antipyrine.
4-amino-5-oxo-1-(4-sulfophenyl)-4H-pyrazole-3-carboxylic acid