Method for preparing 2,3-dihydroxyterephthalic acid (2,3-DHTA)

The invention relates to a method for preparing 2,3-dihydroxyterephthalic acid (2,3-DHTA). The method aims to solve the problems that a preparing method for the 2,3-DHTA in the prior art is complex, the price of raw materials is high, the raw materials cannot be obtained easily, the requirement for reaction conditions is high, the yield is low and product quality is instable. The method for preparing the 2,3-DHTA includes the steps that first, blending and packing are conducted; second, carboxylation and salinization reactions are carried out in a high-pressure reactor; third, a reaction product obtained in the second step undergoes an acidification reaction; fourth, a coarse product obtained in the third step is collected, refined and purified. The yield of the 2,3-DHTA prepared through the method is high and can reach 82.0%, and product purity can reach 99.1%; moreover, production safety is high, production cost is low, and the method is suitable for industrial production. The method is used for preparing the 2,3-DHTA.