Bromcresol purple sultone form, 2-bromo-4-[3-(3-bromo-4-hydroxy-5-methylphenyl)-1,1-dioxo-2,1λ<sup>6</sup>-benzoxathiol-3-yl]-6-methylphenol, Phenol, 4,4‘-(3H-2,1-benzoxathiol-3-ylidene)bis[2-bromo-6-methyl-, S,S-dioxide, Bromocresol Purple, 5,5'-Dibromo-o-cresolsulfonphthalein, 3,3-Bis(3-bromo-4-hydroxy-5-methylphenyl)-3H-benzo[c][1,2]oxathiole 1,1-dioxide