4763 T3D4708 Phenolphthalein Phenolphthalein was withdrawn in Canada due to concerns with carcinogenicity in 1997. 77-09-8 4764 C20H14O4 White powder. 262.5°C 400 mg/L 2B, possibly carcinogenic to humans. (L135) Used for over a century as a laxative. 2014-09-11T02:05:52Z 2014-12-24T20:26:55Z Phenolphthalein C14286 DB04824 true OC1=CC=C(C=C1)C1(OC(=O)C2=CC=CC=C12)C1=CC=C(O)C=C1 C20H14O4 InChI=1S/C20H14O4/c21-15-9-5-13(6-10-15)20(14-7-11-16(22)12-8-14)18-4-2-1-3-17(18)19(23)24-20/h1-12,21-22H InChIKey=KJFMBFZCATUALV-UHFFFAOYSA-N 318.3228 318.089208936 Exogenous Solid 2.41 CHEMBL63857 4600 <p>Hershel B. Prindle, George E. Ham, &#8220;Preparation of phenolphthalein using cation exchange resins and aryl phosphites.&#8221; U.S. Patent US4252725, issued March, 1966.</p>