Clean synthesis of adipic acid catalyzed by complexes derived from heteropoly acid and glycine

Adipic acid was synthesized from cyclohexene and hydrogen peroxide in high yield of 95.1% and excellent selectivity of 99.8% with heteropoly complexes as catalysts. The heteropoly complexes were prepared from heteropoly acids and glycine, and characterized by TG-DSC, elementary analysis, gravimetry and IR spectroscopy. The catalysts prepared showed more efficient than the corresponding heteropoly acids in the synthesis of adipic acid, and W-based heteropoly compounds exhibited higher activities than Mo-based heteropoly compounds. (C) 2008 Elsevier B.V. All rights reserved.