Patent ID: 7470796

Claim:
A method for producing a 2-hydrocarbyl-3,3-bis(4-hydroxyphenyl)phthalimidine of the formula wherein R2 is selected from the group consisting of hydrogen, a halogen, and a hydrocarbyl selected from the group consisting of an alkyl group having 1 to 25 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 25 carbon atoms, and an arylalkyl group having 7 to 25 carbon atoms, wherein the method comprises: heating a reaction mixture comprising a phenolphthalein compound of the formula: wherein R 2 is selected from the group consisting of hydrogen, a halogen, and a hydrocarbyl selected from the group consisting of an alkyl group having 1 to 25 carbon atoms, a cycloalkyl group having 3 to 8 carbon atoms, an aryl group having 6 to 25 carbon atoms, and an arylalkyl group having 7 to 25 carbon atoms, a primary aromatic amine of the formula R 1 -NH 2 , wherein R 1 is an aromatic group having 6 to 25 carbon atoms, and hydrogen chloride fluid; neutralizing the mixture with sodium bicarbonate; precipitating an adduct of the 2-hydrocarbyl-3,3-bis(4-hydroxyphenyl)phthalimidine and the primary aromatic amine by adding an aromatic hydrocarbon to the neutralized reaction mixture; and heating the precipitated adduct with an alcohol to produce the 2-hydrocarbyl-3,3-bis(4-hydroxyphenyl)phthalimidine.