Notes - Benzofuran from Saccharic Acid

Synthesis, Chemistry and Applications of 5‐Hydroxymethyl‐furfural and Its Derivatives

“…Later on, numerous chemists modified this method changing the nature of the dehydrating agent [188][189][190][191] and the kind of the substrate. [192][193][194][195][196][197] All these reactions required drastic conditions -the temperature must be over 120 °C, the required time of the reaction should exceed 20 h. Moreover all these methods were not selective 198 (a number of side-products was detected) and were inefficient (yields were less than 50%). Only one method from this group gave the prospectively efficient preparation of FDCA on a large scale.…”

Metabolism of d-glucuronolactone in mammalian systems. Identification of d-glucaric acid as a normal constituent of urine

“…However, the method used by these workers to isolate the compound involved heating a dried urine extract with 25 % sulphuric acid for 1 hr., followed by steam-distillation. By prolonged heating of potassium hydrogen D-glucarate with strong acid, furan-2,5-dicarboxylic acid may be prepared in good yield (Haworth, Jones & Higgins, 1945;Cope & Keller, 1956); the reaction requires the loss of 3 molecules of water per molecule of Dglucaric acid. It therefore appears probable that much of the furan-2,5-dicarboxylic acid isolated after ingestion of D-glucuronolactone arises by this process.…”

Engineering the future: Perspectives in the 2,5-furandicarboxylic acid synthesis

“…It has been found that the highest selectivities for the synthesis of furans might be obtained by application of catalysts with the strong Brønsted acid sites like ion exchange resins (Amberlyst-15), sulfonated silica, zeolites and niobium oxide. The first document published in 1956 shows the possibility to dehydrate glucaric acid to FDCA using concentrated HBr (48%) [28,29]. In this work the yield obtained was of 50% after 27 hours of reaction.…”