The Synthesis Of Quinoline Derivatives Via Three Green Methods

As a kind of very important nitrogen heterocycles,quinoline and its derivatives,depending on its important biological and pharmacological activities,have obtained widely application in pharmaceutical,pesticide and dye.In recent years,the chemical synthesis methods,especially the green synthesis methods,have become a research focus for the workers in the organic chemistry.This paper explored three green methods for preparation of quinoline derivatives by the Friedl(?)nder condensation reaction,the main contents are as follows:The research on the synthesis of quinoline derivatives catalyzed by ?-chymotrypsin in methanol solvent.?-Chymotrypsin was chosen as the best catalyst through the selection of enzyme sources,and the effects of reaction mediums,temperatures and dosages of enzyme on reaction were investigated,then,under the condition of 60 ?,the reactions between a series of 2-aminoaryl ketones and ?-methylene ketones were catalyzed by 20 mg ?-chymotrypsin,11 quinoline derivatives were obtained in 40% ~ 90% yield.Comparing with the traditional catalyst,the catalyst has higher catalytic activity and good biological intermiscibility,which shown good substrate applicability in mild reaction condition.The research on the synthesis of quinoline derivatives catalyzed by ?-chymotrypsin in ionic liquid aqueous solution.The effects of ionic liquids,ionic liquid's water contents,temperatures and dosages of enzyme on reaction were investigated,then,at 55?,in 20% ionic liquid(1-ethyl-3-methylimidazolium tetrafluoroborate)aqueous solution,the reactions between a series of 2-aminoaryl ketones and ?-methylene ketones were catalyzed by 10 mg ?-chymotrypsin,14 quinoline derivatives were obtained in 40% ~ 94% yield.Comparing with the organic medium,this system had more moderate conditions,less enzyme loadings and higher catalytic efficiency,above all,it avoided the use of harmful organic solvent.The research on the synthesis of quinoline derivatives in deep eutectic solvent.The effects of some deep eutectic solvents,solvents,reaction temperatures and enzyme loadings on reaction were investigated,and a series of substrates were expanded in 0.5 mL DES(choline chloride/oxalic acid = 1 : 1)at 80?,11 quinoline derivatives were obtained in 67% ~ 94% yield.Comparing with the previous research,this process had shorter reaction time,higher yield,at the same time,the DES can be recycled,which was closer to the requirement of green chemistry.