Methods for producing and purifying 2-hydrocarbyl-3,3-bis(4-hydroxyaryl)phthalimidine monomers and polycarbonates derived therefrom

1. A method for producing a 2-hydrocarbyl-3,3-bis(4-hydroxyaryl)phthalimidine of Formula (I),

said method comprising:

(A) heating a reaction mixture comprising:

(i) a primary hydrocarbyl amine of Formula (II),

—R 1 —NH2,

(ii) a phenolphthalein compound of Formula (III),

wherein R 1 is selected from a group consisting of a hydrogen and a hydrocarbyl group, R 2 is selected from the group consisting of a hydrogen, a hydrocarbyl group, and a halogen, and R 3 is selected from the group consisting of a hydrogen and a hydrocarbyl group; and forming said 2-hydrocarbyl-3,3-bis(4-hydroxyaryl)phthalimidine, wherein the hydrocarbyl group is selected from the group consisting of an alkyl group, a cycloalkyl group, and an aryl group;

(B) forming an adduct of said 2-hydrocarbyl-3,3-bis(4-hydroxyaryl)phthalimidine and said primary hydrocarbyl amine;

(C) precipitating said adduct; and

(D) decomposing said adduct to produce said 2-hydrocarbyl-3,3-bis(4-hydroxyaryl)phthalimidine.

2. The method of claim 1 , wherein step (A) is performed in the presence of an acid catalyst.

3. The method of claim 1 , wherein steps (A) and (B) are performed simultaneously by performing the heating in step (A) with an excess of said primary hydrocarbyl amine to form said adduct in situ.

4. The method of claim 1 , wherein after step (A) and before step (B) the 2-hydrocarbyl-3,3,-bis(4-hydroxyaryl)phthalimidine is isolated in crude form, and step (B) is performed by dissolving the crude 2-hydrocarbyl-3,3,-bis(4-hydroxyaryl)phthalimidine with a further amount of the primary hydrocarbyl amine.

5. The method of claim 1 , further comprising neutralizing the reaction mixture prior to precipitating said adduct, wherein neutralizing comprises adding a base to the reaction mixture.

6. The method of claim 1 , wherein said step (B) is performed by adding at least 3 moles of primary hydrocarbyl amine in the reaction mixture.

7. The method of claim 4 , wherein said crude 2-hydrocarbyl-3,3-bis(4-hydroxyaryl)phthalimidine is reacted with at least 2 moles of primary hydrocarbyl amine.

8. The method of claim 1 , wherein said step (D) of decomposing the adduct comprises heating said adduct with an aliphatic alcohol.

9. The method of claim 8 , wherein said aliphatic alcohol is selected from the group consisting of methanol, ethanol, iso-propanol, iso-butanol, n-butanol, tertiary butanol, n-pentanol, iso-pentanol, and mixtures of at least one the foregoing aliphatic alcohols.

10. The method of claim 1 , wherein said step (D) of decomposing the adduct comprises the steps of:

dissolving said precipitated adduct in an aqueous base to provide a first solution;

mixing the first solution with a water-immiscible aromatic hydrocarbon solvent, to form, an aqueous layer and an organic layer;

treating the aqueous layer with a solid adsorbent to provide a second solution; and

adding an aqueous acid to the second solution to precipitate said 2-hydrocarbyl-3,3-bis(4-hydroxyaryl)phthalimidine.

11. The method of claim 10 , wherein said mixing of said first solution with the aromatic hydrocarbon solvent is done at least twice.

12. The method of claim 10 , wherein said aqueous base comprises an additive selected from the group consisting of; an alkali metal, alkaline earth metal hydroxides, carbonates, and bicarbonates.

13. The method of claim 1 , wherein the step (D) further comprises the steps of heating said 2-hydrocarbyl-3,3-bis(4-hydroxyaryl)phthalimidine with an aliphatic alcohol.

14. The method of claim 13 , wherein said aliphatic alcohol is selected from the group consisting of; methanol, ethanol, iso-propanol, iso-butanol, n-butanol, tertiary butanol, n-pentanol, iso-pentanol, and mixtures comprising at least one the foregoing aliphatic alcohols.

15. The method of claim 2 , wherein said acid catalyst is selected from the group consisting of a substituted or an unsubstituted aliphatic amine hydrochloride, an aromatic amine hydrochloride, and mixtures of the foregoing amine hydrochlorides.

16. The method of claim 1 , wherein said step (A) of heating the reaction mixture is conducted at a temperature of 140° C. to 185° C.

17. The method of claim 1 , wherein said step (A) of heating the reaction mixture is conducted at a temperature of 140° C. to 150° C.

18. The method of claim 1 , wherein said step (A) of heating the reaction mixture further comprises removing a distillate comprising water.

19. The method of claim 1 , wherein said step (A) of heating the reaction mixture has a duration of 4 hours to 48 hours.

20. The method of claim 1 , wherein said step (A) of heating the reaction mixture has a duration of 22 hours to 30 hours.

21. The method of claim 10 , wherein said water-immiscible aromatic hydrocarbon solvent comprises a solvent selected from the group consisting of toluene, isomeric xylenes or mixtures thereof, chlorobenzene, and mesitylene.

22. The method of claim 1 , wherein said 2-hydrocarbyl-3,3-bis(4-hydroxyaryl)phthalimidine is 2-phenyl-3,3-bis(4-hydroxphenyl)phthalimidine.

23. The method of claim 22 , wherein said 2-phenyl-3,3-bis(4-hydroxyphenyl)phthalimidine comprises less than or equal to 1,500 parts per million of phenolphthalein based on total weight of 2-phenyl-3,3-bis(4-hydroxyphenyl)phthalimidine.