| 摘要 |
Described is a process for dicarboxylating dihydric phenols, notably those where the hydroxyl groups are in the para- or the ortho- position vis-à-vis one another. More particularly, the invention pertains to a process for preparing 2,5-dihydroxyterephthalic acid (2,5 DHTA). The invention consists in that dihydric phenol is contacted with carbon dioxide in the presence of an alkali metal carbonate, the reaction being carried out in the presence of an alkali metal formate, at a temperature above the formate's melting point. The invention has several advantages over the well-known Kolbe-Schmitt reaction and other known carboxylation reactions, such as a lower operating pressure, higher yields, and/or shorter reaction times.
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