2,7-Naphthalenedisulfonic acid, 5-((5-chloro-6-methyl-2-(methylsulfonyl)-4-pyrimidinyl)amino)-4-hydroxy-3-(phenylazo)-, disodium salt 4-((5-Chloro-4-methyl-2-(methylsulfonyl)-6-pyrimidyl)amino)-5-hydroxy-6-(phenylazo)-2,7-naphthalenedisulfonic acid, disodium salt 72894-30-5