Biomass to Aromatic Amine Module: Alkali Catalytic Conversion of <i>N</i>‐Acetylglucosamine into Unsubstituted 3‐Acetamidofuran by Retro‐Aldol Condensation
Changqu Lin, Hao Yang, Xin Gao, Yue Zhuang, Caojian Feng, Hongli Wu, Haifeng Gan, Fei Cao, Ping Wei, Pingkai Ouyang
Abstract
Abstract Aminofurans are widely used in drug synthesis as aromatic modules analogous to aniline. However, unsubstituted aminofuran compounds are difficult to prepare. In this study, a process for the selective conversion of N ‐acetyl‐ d ‐glucosamine (NAG) into unsubstituted 3‐acetamidofuran (3AF) is developed. The yield of 3AF from NAG catalyzed by a ternary Ba(OH) 2 −H 3 BO 3 −NaCl catalytic system in N ‐methylpyrrolidone at 180 °C for 20 min can reach 73.9 %. Mechanistic studies reveal that the pathway to 3AF starts with a base‐promoted retro‐aldol condensation of the ring‐opened NAG, affording the key intermediate N ‐acetylerythrosamine. Judicious selection of the catalyst system and conditions enables the selective conversion of biomass‐derived NAG into 3AF or 3‐acetamido‐5‐acetylfuran.