Method for producing phenolphthalein using a heteropolyacid catalyst

1 112 2 112 1 112 2 112 A method for producing a phenolphthalein compound comprises: reacting a phenolic compound of the formula: wherein Ris a hydrogen or a C-Chydrocarbyl group, with a phthalic anhydride compound of the formula: wherein Ris a hydrogen, a C-Chydrocarbyl 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 Ris independently a hydrogen or a C-Chydrocarbyl group; and Ris a hydrogen, a C-Chydrocarbyl group, or a halogen; wherein the heterogeneous catalyst comprises, on a porous support, a calcination product of a heteropolyacid composition.