Molybdate sulfonic acid: preparation, characterization, and application as an effective and reusable catalyst for octahydroxanthene-1,8-dione synthesis
作者:Bahador Karami、Zahra Zare、Khalil Eskandari
DOI:10.2478/s11696-012-0263-y
日期:2013.1.1
Molybdate sulfonic acid (MSA) as a highly efficient catalyst was synthesized and employed for the synthesis of octahydroxanthene-1,8-dione derivatives. MSA efficiently catalyzed condensation of a wide range of aryl aldehydes and cyclohexane-1,3-diones to obtain octahydroxanthene-1,8-diones. It was characterized by X-ray fluorescence (XRF), X-ray diffraction (XRD), and FT-IR spectroscopy. This catalyst
safer procedure from anhydrous sodium tungstate with chlorosulfonic acid (1:2 mole) in n-hexane (Scheme 1).16–18 We now describe the use of TSA for the synthesis of 1,8-dioxoöctahydroxanthenes 3 by condensation of 1,3-cyclohexanediones 1 with aromatic aldehydes 2 undersolvent-freeconditions (Scheme 2). The structures of the products were deduced from their IR, NMR spectroscopic data and their melting