The molecule is an organosulfonate oxoanion obtained by deprotonation of the sulfo group of 5-[(4-amino-5-methoxy-2-methylphenyl)diazenyl]-2-methoxybenzene-1-sulfonic acid. It is a conjugate base of a Sirius scarlet GG (acid form).
5-[(4-amino-5-methoxy-2-methylphenyl)diazenyl]-2-methoxybenzenesulfonate