Abstract: Disclosed herein is a method comprising reacting a phenolphthalein material and a primary hydrocarbyl amine in the presence of an acid catalyst to form a reaction mixture comprising 2-hydrocarbyl-3,3-bis(4-hydroxyaryl)phthalimidine, wherein the phenolphthalein material comprises greater than or equal to 95 weight percent phenolphthalein, based on the total weight of phenolphthalein material; quenching the reaction mixture and treating the quenched reaction mixture to obtain a first solid. The first solid is then triturated with a trituration solvent and washed to obtain a second solid, wherein the second solid comprises greater than or equal to 97 weight percent 2-hydrocarbyl-3,3-bis(4-hydroxyaryl)phthalimidine, based on the total weight of the second solid. The second solid may be polymerized to form a polycarbonate.

Abstract: Methods for purifying a p,p-bisphenol A generally include distilling a feed stream comprising p,p-BPA in a distillation column at a pressure less than or equal to 20 millibars. The distillation column separates the bisphenol feed stream to produce a light fraction, an intermediate fraction and a heavy fraction. The intermediate fraction comprising the purified bisphenol contains lesser impurities that the p,p-BPA in the feed stream. In one embodiment, the intermediate stream is recovered using a side-draw. The side-draw is located between a first zone and a third zone in the distillation column.