65620-37-3

Benzenesulfonic acid,4-[1,3,6,7-tetrahydro-4-methyl-3,6-dioxo-5-[[1,2,3,6-tetrahydro-4-methyl-3,6-dioxo-2-(4-sulfophenyl)-5H-pyrazolo[3,4-b]pyridin-5-ylidene]methyl]-2H-pyrazolo[3,4-b]pyridin-5-yl]-, dipotassium salt