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/Al2O3=40)>H‐montmorillonite (K‐10)>Amberlyst15>H‐ZSM‐5 (SiO2/Al2O3=300)>TiO2>γ‐Al2O3>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 27Al 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

Magnesium Oxide‐Catalyzed Conversion of Chitin to Lactic Acid

Abstract Invited for this month's cover are the groups of Prasert Reubroycharoen at the Chulalongkorn University (Thailand) and Aritomo Yamaguchi at the National Institute of Advanced Industrial Science and Technology (Japan). The cover picture shows the the conversion of chitin, which is generated by food processing, into lactic acid with catalysis by magnesium oxides. Although chitin, a main component of the shells of crustaceans, can be converted to valuable products by means of homogeneous catalysis, most of the chitin is treated as industrial waste because use of homogeneous catalysts is compromised by difficulties associated with product separation from the catalysts and the recyclability of the catalysts. Thus, a method for converting chitin to useful chemicals, such as lactic acid, by using solid catalysts would be beneficial. Magnesium oxide catalysts can be reused twice without loss of activity. Read the full text of their Full Paper at 10.1002/open.202000303

Magnesium Oxide‐Catalyzed Conversion of Chitin to Lactic Acid

Abstract Although chitin, an N‐acetyl‐D‐glucosamine polysaccharide, can be converted to valuable products by means of homogeneous catalysis, most of the chitin generated by food processing is treated as industrial waste. Thus, a method for converting this abundant source of biomass to useful chemicals, such as lactic acid, would be beneficial. In this study, we determined the catalytic activities of various metal oxides for chitin conversion at 533 K and found that MgO showed the highest activity for lactic acid production. X‐ray diffraction analysis and thermogravimetry‐differential thermal analysis showed that the MgO was transformed to Mg(OH)2 during chitin conversion. The highest yield of lactic acid (10.8 %) was obtained when the reaction was carried out for 6 h with 0.5 g of the MgO catalyst. The catalyst could be recovered as a solid residue after the reaction and reused twice with no decrease in the lactic acid yield