2-[[[2,5-Dichloro-4-[2-methyl-4-(diethylamino)phenylazo]phenyl]sulfonyl]amino]ethanesulfonic acid

2-[[[2,5-Dichloro-4-[[4-(diethylamino)-2-methylphenyl]azo]phenyl]sulfonyl]amino]ethanesulfonic acid