1-Naphthalenesulfonic acid, 6-diazo-5,6-dihydro-5-oxo-, phenyl ester 2-Diazo 1-naphthol 5-sulfonate ester of phenol 23295-00-3 EINECS 245-564-0 Phenyl 6-diazo-5,6-dihydro-5-oxonaphthalene-1-sulphonate