Catalytic method for producing phenolphthalein compounds

A method of producing a phenolphthalein comprises reacting a phenolic compound of the formula (I) wherein R1 is a hydrogen or a C1 -C12 hydrocarbyl group, with a phthalic anhydride compound of the formula (II) wherein R2 is a hydrogen, a C1 -C12 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 (III) wherein each R1 is independently a hydrogen or a C1 -C12 hydrocarbyl group, and R2 is a hydrogen, a C1 -C12 hydrocarbyl group, or a halogen; wherein the heterogeneous catalyst comprises a metal oxide composition in combination with a porous support, wherein the metal is molybdenum, tungsten, or a combination comprising at least one of the foregoing metals.