Method for producing phenolphthalein using a heteropolyacid catalyst

1. A method for producing a phenolphthalein compound comprising:

reacting a phenolic compound of the formula:

wherein R 1 is a hydrogen or a C 1 -C 12 hydrocarbyl group, with a phthalic anhydride compound of the formula:

wherein R 2 is a hydrogen, a C 1 -C 12 hydrocarbyl group, or a halogen, in the presence of a heterogeneous catalyst and a promoter to form a reaction mixture comprising a phenolphthalein compound of the formula:

wherein each R 1 is independently a hydrogen or a C 1 -C 12 hydrocarbyl group; and R 2 is a hydrogen, a C 1 -C 12 hydrocarbyl group, or a halogen;

wherein the heterogeneous catalyst comprises, on a porous support, a calcination product of a heteropolyacid composition.

2. The method of claim 1 wherein the heteropolyacid composition comprises molybdenum, tungsten, vanadium, or a combination comprising at least one of the foregoing metals.

3. The method of claim 1 wherein the heteropolyacid composition comprises a compound, or structural units derived therefrom, of the formula:

(H) n (M 4 )(M 5 ) 12 O 40

wherein the subscript n is 3, 4, 5, or 6, M 4 is phosphorus or silicon, and M 5 is tungsten, molybdenum, or a combination comprising at least one of the foregoing metals.

4. The method of claim 3 wherein the heteropolyacid is silicotungstic acid, tungstophosphoric acid, molybdophosphoric acid, or a combination comprising at least one of the foregoing heteropolyacids.

5. The method of claim 1 wherein the porous support is zirconium oxide, titanium oxide, cerium oxide, silicon oxide, aluminum oxide, magnesium oxide, niobium oxide, tin oxide, aluminosilicate, or a combination comprising at least one of the foregoing.

6. The method of claim 1 wherein the heteropolyacid composition comprises tungsten and the porous support comprises zirconium oxide.

7. The method of claim 1 wherein the heteropolyacid composition and the porous support are, respectively, silicotungstic acid and zirconia, tungstophosphoric acid and zirconia, tungstophosphoric acid and titania, tungstophosphoric acid and both zirconia and aluminosilicate, or a combination comprising at least one of the foregoing pairs of heteropolyacid composition and porous support.

8. The method of claim 1 wherein the heterogeneous catalyst is the product of a process comprising contacting a solid support precursor with a heteropolyacid composition; and calcining the contacted solid support precursor and heteropolyacid composition to provide the heterogeneous catalyst, wherein the solid support precursor is zirconium oxyhydroxide, titanium hydroxide, a C 1 -C 6 alkyl-substituted substituted orthosilicate, zirconium oxychloride, or a combination comprising at least one of the foregoing solid support precursors.

9. The method of claim 1 wherein the porous support comprises a combination of an aluminosilicate zeolite and zirconium oxide.

10. The method of claim 1 wherein the porous support comprises zirconium oxide.

11. The method of claim 1 wherein the promoter is chlorosulphonic acid, a C 1 -C 12 alkyl sulphonic acid, a C 6 -C 12 aryl sulphonic acid, a C 1 -C 12 alkyl C 6 -C 12 aryl sulphonic acid, a halogenated C 1 -C 12 alkyl sulphonic acid, a halogenated C 6 -C 12 aryl sulphonic acid, a halogenated C 1 -C 12 alkyl C 6 -C 12 aryl sulphonic acid, trichloroacetic acid, triflic acid, boron trifluoride, or a combination comprising at least one of the foregoing promoters.

12. The method of claim 1 wherein the promoter is chlorosulphonic acid.

13. The method of claim 1 wherein after reacting, the heterogeneous catalyst is separated from the reaction mixture, then regenerated.

14. The method of claim 13 wherein the heterogeneous catalyst is used in a total of two to four cycles of reaction in a batch process.

15. The method of claim 13 , wherein the heterogeneous supported catalyst is regenerated by calcination at a temperature of 400 to 900° C.

16. The method of claim 1 , wherein the method further comprises:

quenching the reaction mixture comprising the phenolphthalein compound with a first organic solvent in which the phenolphthalein compound dissolves to provide a first quenched reaction mixture;

filtering the first quenched reaction mixture to provide a solid residue comprising the heterogeneous catalyst and a filtrate comprising the organic solvent and the phenolphthalein compound.

17. The method of claim 16 , further comprising regenerating the heterogeneous catalyst in the solid residue.

18. The method of claim 16 , further comprising

removing the first organic solvent from the filtrate to provide a residue comprising the phenolphthalein compound and

heating the residue with a second, non-polar organic solvent to provide a precipitate comprising the phenolphthalein compound, wherein the phenolphthalein compound in the precipitate has a purity of greater than or equal to 80 weight percent, based on the weight of the precipitate, and the phenolphthalein compound is obtained in a yield of greater than or equal to 70 mole percent, based on the moles of the phthalic anhydride compound.

19. A method for producing a phenolphthalein compound comprising:

reacting a phenolic compound of the formula:

wherein R 1 is a hydrogen or a C 1 -C 12 hydrocarbyl group, with a phthalic anhydride compound of the formula:

wherein R 2 is a hydrogen, a C 1 -C 12 hydrocarbyl group, or a halogen, in the presence of a heterogeneous catalyst and a promoter to form a reaction mixture comprising a phenolphthalein compound of the formula:

wherein each R 1 is independently a hydrogen or a C 1 -C 12 hydrocarbyl group; and R 2 is a hydrogen, a C 1 -C 12 hydrocarbyl group, or a halogen;

wherein the heterogeneous catalyst comprises, on a porous support, a calcination product of an oxygen-containing inorganic heteropolyacid comprising a polyatom selected from the group consisting of molybdenum, tungsten, vanadium, niobium, or a combination thereof, and a central heteroatom selected from the group consisting of phosphorous, silicon, germanium, boron, cobalt, and a combination thereof.

20. A method for producing a phenolphthalein, comprising:

reacting a phenolic compound of the formula:

wherein R 1 is a hydrogen, with a phthalic anhydride compound of the formula:

wherein R 2 is a hydrogen, a C 1 -C 12 hydrocarbyl group, or a halogen, in the presence of a heterogeneous catalyst and a promoter to form a reaction mixture comprising a phenolphthalein compound of the formula:

wherein each R 1 is a hydrogen, and R 2 is a hydrogen, a C 1 -C 12 hydrocarbyl group, or a halogen; wherein the heterogeneous catalyst comprises, on a porous support, a calcination product of a heteropolyacid composition that comprises a compound, or structural units derived from the compound, of the formula:

(H) n (M 4 )(M 5 ) 12 O 40

wherein the subscript n is 3 or 4, M 4 is phosphorus or silicon, and M 5 is tungsten, molybdenum, or a combination comprising at least one of the foregoing metals;

quenching the reaction mixture comprising the phenolphthalein compound with a first organic solvent in which the phenolphthalein compound dissolves to provide a first quenched reaction mixture comprising dissolved phenolphthalein compound;

filtering the first quenched reaction mixture to provide a solid residue comprising the heterogeneous catalyst and a filtrate comprising the organic solvent and the phenolphthalein compound;

removing the organic solvent from the filtrate to provide a residue comprising the phenolphthalein compound; and

regenerating the heterogeneous supported catalyst.