Efficient methods for making tetrahalophthalate esters having excellent purity

A method for making a tetrahalophthalate ester featuring reduced levels of metal ion contamination, color body contamination and acidity, comprising:

• providing a pretreated mixture including a tetrahalophthalic compound, a first organic alcohol, sulfuric acid and a member selected from the group consisting of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate or a combination thereof;
• wherein the sulfuric acid:tetrahalophthalic compound ratio is less than about 4:10,000 by weight;
• subjecting the pretreated mixture to reflux conditions in the presence of a titanate catalyst for a period of time effective to yield a crude reaction product, the crude reaction product including a tetrahalophthalate ester, a portion of the first organic alcohol that remained unreacted and the titanate catalyst;
• removing a substantial portion of the first organic alcohol from the crude reaction product to provide a stripped product;
• hydrolyzing the titanate catalyst in the stripped product by introducing an aqueous base selected from the group consisting of sodium carbonate, sodium bicarbonate, potassium carbonate, potassium bicarbonate and a combination thereof into the stripped product to provide an aqueous intermediate;
• removing water from the aqueous intermediate to provide a nonaqueous intermediate;
• dispersing a solid adsorbent into the nonaqueous intermediate to provide a slurry;
• and
• filtering the slurry to produce a filter cake and a tetrahalophthalate ester product.