2303-01-7 Cresol purple NSC9607 Phenol, 4,4'-(3H-2,1-benzoxathiol-3-ylidene)bis[3-methyl-, S,S-dioxide m-Cresol purple m-Cresol, 4,4'-(3H-2,1-benzoxathiol-3-ylidene)di-, S,S-dioxide m-Cresolsulfonephthalein