Selective synthesis of aromatic dicarboxylic acid using cyclodextrin as catalyst

✍ Scribed by Hidefumi Hirai

• Publisher: John Wiley and Sons
• Year: 1997
• Tongue: English
• Weight: 351 KB
• Volume: 8
• Category: Article
• ISSN: 1042-7147
• DOI: 10.1002/(sici)1099-1581(199711)8:11<666::aid-pat699>3.0.co;2-f

✦ Synopsis

The selective synthesis of terephthalic acid from benzoic acid with carbon tetrachloride, copper powder and aqueous alkali was achieved by the use of ␤-cyclodextrin ( ␤-CyD) as a catalyst at 60°C under nitrogen of atmospheric pressure, producing terephthalic acid in 74 mol% yield with 100% selectivity. The carboxylation of 4-biphenylcarboxylic acid with carbon tetrachloride, copper powder and aqueous alkali using ␤-CyD under similar conditions produced 4,4Ј-biphenyldicarboxylic acid in 71 mol% with 100% selectivity. 2,6-Naphthalenedicarboxylic acid was synthesized by the carboxylation using ␤-CyD under similar conditions in 67 mol% yield with 84% selectivity. When ␣-CyD or ␥-CyD was used instead of ␤-CyD, the reaction hardly proceeded. The conformations of CyD-aromatic monocarboxylate inclusion complexes in aqueous alkaline solution were determined by the nuclear magnetic resonance spectroscopy using 1 H homonuclear Overhauser enhancement on the rotating frame. The essential factor of the carboxylation was the inclusion complex formations of ␤-CyD with aromatic monocarboxylate and ␤-CyD with carbon tetrachloride in the reaction mixture. The high selectivity was ascribed to the conformation of the ␤-CyD-aromatic monocarboxylate inclusion complex.