METHODS FOR PRODUCING AND PURIFYING 2-ARYL-3, 3-BIS ( 4 -HYDROXYARYL) PHTHALIMIDINE DERIVATIVES

摘要

Disclosed herein is a method for producing a purified 2-aryl-3,3-bis(4-hydroxyaryl) phthalimidine of formula (I) wherein R1 is hydrogen or a C1-25 hydrocarbyl group and R2 is a hydrogen, a C1-25 hydrocarbyl group, or a halogen, and wherein the method comprises dissolving a crude phthalimidine compound in an aqueous base solution; precipitating the dissolved, crude phthalimidine compound from the aqueous base solution by adding an acid in an amount effective to lower the pH of the solution to 9.0 to 12.0, to provide a semicrude phthalimidine compound; and isolating the semicrude phthalimidine compound from the aqueous base solution, to provide the purified 2-aryl-3,3-bis (4-hydroxyaryl) phthalimidine of formula (I), and having a phenolphthalein compound content of less than 2,500 ppm, based on the weight of the purified 2-aryl-3,3-bis(4-hydroxyaryl) phthalimidine. Subsequent trituration with aqueous methanol and recrystallization from isopropanol can result in product having levels of phenolphthalein derivatives that are not detectable.