Conversion of N-Acetylglucosamine to 3-Acetamido-5-Acetylfuran over Al-Exchanged Montmorillonite.

Abstract

3-Acetamido-5-acetylfuran (3A5AF) is a potential platform compound for the production of nitrogen-containing pharmaceuticals and chemicals. 3A5AF can be obtained by dehydration of chitin or its monomer, N-acetylglucosamine (NAG). Here, we examined the use of solid catalysts for the dehydration of NAG to 3A5AF to achieve a more economical process that uses a recyclable catalyst. NAG was dehydrated using various solid catalysts in the presence of NaCl and N,N-dimethyl acetamide as solvent at 433 K. The yield of 3A5AF with the solid catalysts decreased in the following order: Al-exchanged montmorillonite>H-ZSM-5 (SiO2 /Al2 O3 =40)>H-montmorillonite (K-10)>Amberlyst15>H-ZSM-5 (SiO2 /Al2 O3 =300)>TiO2 >γ-Al2 O3 >ZrO2 >SiO2 ⋅ MgO>Na-montmorillonite. The highest yield of 3A5AF (14 %) was obtained with the Al-exchanged montmorillonite. The montmorillonite catalysts were characterized by using inductively coupled plasma optical emission spectroscopy, energy-dispersive X-ray spectroscopy, N2 adsorption, Fourier-transformed infrared spectroscopy, X-ray diffraction, and 27 Al magic-angle spinning nuclear magnetic resonance spectroscopy (MAS-NMR). In addition, a combined catalyst of Al-exchanged montmorillonite and Cl- from synthetic hydrotalcite was found to be an active and recyclable solid catalyst for NAG dehydration to 3A5AF.