Synthesis And Antibacterial Activity Of Two Types Of Quinoline And Pyridine Nitrogen-containing Heterocyclic Compounds

Quinoline and pyridine compounds have important biological activities and are many pesticide intermediates and chemical raw materials.Green and highly efficient synthetic quinoline and pyridine skeleton compounds are getting more and more attention in the process of pesticide creation.In this text,a simple synthetic method of 3-acylquinoline and coumarin pyridine skeleton were studied.27 kinds of3-acylquinoline and 11 kinds of coumarin pyridine compounds were synthesized.The structure of the compounds were determined by ¹H NMR and ¹³C NMR and high-resolution mass spectrometry.These methods have the advantages of novelty,high efficiency,environment friendly,mild conditions and so on.A broad range of substrates can be tolerated in this reaction,and antibacterial activity of the synthetic compounds were tested.The activity data showed that these two types of compounds possessed certain capability of antibacterial,which provides a certain active basis for studying these two compounds.The main contexts are as follows:1.Using p-toluidine and enamine as raw materials,under the catalytic action of p-toluenesulfonic acid,solvent dimethyl sulfoxide?DMSO?provides a carbon source to synthesize 3-acylquinoline in one step.Using enamine and 4-amine coumarin compounds as raw materials,under the conditions of 1,2-dichloroethane?DCE?as solvent by one step synthesis of pyridine compounds that combine with coumarin structural.2.The best conditions for synthesizing 3-acylquinoline are:additives Ts OH.H₂O ?2.0 equiv?,DMSO?1.0 m L?,oxidant?air?,temperature?110°C?,time?24 h?;The best conditions for synthesis of coumarin pyridine are:Ts OH.H₂O?2.0 equiv?,DCE?1.0 m L?,oxidant?air?,temperature?100°C?,time?24 h?.3.Examining the applicability of substrate under the optimal reaction conditions and the results showed that the yield of the product obtained when the substituents on the phenyl ring are electron-withdrawing and electron-donating is different,and when the position and number of substituents on the phenyl ring are changed,the yield of the product is also different,so the steric hindrance effect is not conducive to the reaction.4.A possible mechanism for synthesizing 3-acylquinoline skeleton was proposed and verified.According to the experimental date,it was confirmed that the reaction were performed with DMSO as C source to provide 3-acylquinoline compounds,and the carbon source provided by DMSO was at the 2-position of 3-acylquinoline.5.Some compounds were selected for thestudy of antibacterial activity.The synthesized 3-acylquinoline and coumarin pyridine have certain antibacterial activity.According to the activity date,the two types of compounds have shown that the bacteria such as Wheat scab,apple rot,and rape sclerotium have certain inhibitory effects.Compounds 6b,6d,6e,6i,and 6j at a concentration of 20 mg/L have an inhibition rate of more than 90%against Sclerotinia sclerotiorum and Apple rot.The EC₅₀values??of 6 i for apple rot and Rhizoctonia sclerotiorum were 6.793 mg/L and 13.398 mg/L,respectively,and the EC₅₀value of 6j for S.sclerotiorum was12.801 mg/L.