A simple continuous reaction for the synthesis of quinoline compounds

• Published in: Green chemistry : an international journal and green chemistry resource : GC Vol. 24; no. 4; pp. 1714 - 172
• Main Authors: Song, Suhong, Dai, Yuyu, Hong, Yunyang, Li, Xiaoqing, Yan, Xinhuan
• Format: Journal Article
• Language: English
• Published: Cambridge Royal Society of Chemistry 21.02.2022
• Subjects: Aluminum oxide; Catalysts; Chemical synthesis; Ethanol; Flow rates; Flow velocity; Green chemistry; Mass ratios; Oxidants; Oxidizing agents; Quinoline; Transitional aluminas
• ISSN: 1463-9262; 1463-9270
• DOI: 10.1039/d1gc03064g

In this paper, 2-methylquinoline compounds were synthesized continuously from nitroarenes and the ethanol/water system by a simple hydrogen transfer reaction in the presence of the Ru-Fe/γ-Al 2 O 3 catalyst. This new simple synthesis reaction was heterogeneous and continuous. At the same time, green solvents were used, and strong acids, oxidants, and other environmentally harmful substances were not added, which conformed to the principles of green chemistry. Through the impregnation method, the nanocatalysts with a smaller particle size and uniform dispersion were obtained on the γ-Al 2 O 3 particles (1-2 mm) and had good activity. The effects of the alcohol water volume ratio, pressure, flow rate and Ru-Fe mass ratios on the yields of 2-methylquinoline compounds in the reaction were investigated. The reaction can proceed smoothly for nitroarenes with different substituents, and a moderate to good yield (46%-88%) was obtained. Using nitroarenes, sustainable solvents and a solid catalyst to synthesize quinoline compounds through a simple and continuous hydrogen transfer reaction.