1-Naphthalenesulfonic acid, 6-diazo-5,6-dihydro-5-oxo-, methylenedi-1,2-naphthalenediyl ester 148925-84-2 2481-85-8 33910-44-0 67120-29-0 EINECS 251-737-1 Methylenedinaphthalene-1,2-diyl bis(6-diazo-5,6-dihydro-5-oxonaphthalene-1-sulphonate)