What Are The Problems In The Synthesis Of Fluorene-9-bisphenol?

At present, industrial condensation reactions often use concentrated sulfuric acid and gaseous hydrogen chloride as catalysts for the synthesis of fluorene-9-bisphenol, but there are many by-products, which are difficult to separate, which affects the melting point and color of the product, pollutes the environment, and produces large amounts of waste acid wastewater , Post-processing is difficult, and the equipment is severely corroded, expensive corrosion-resistant materials are required, and the operating cost increases.