123333-63-1 128915-86-6 3,4,5,6-Tetrabromophenolsulfonephthalein 3456-Tbsp 4,4'-(4,5,6,7-Tetrabromo-3H-2,1-benzoxathiol-3-ylidene)bisphenol S,S-dioxide 77172-72-6 NSC 624919 Phenol, 4,4'-(4,5,6,7-tetrabromo-3H-2,1-benzoxathiol-3-ylidene)bis-, S,S-dioxide Tetrabromosulfonephthalein