Synthesis And Antifungal Activities Of Tri/difluoromethyl-containing Quinoxaline-2(1H)-one Derivatives

Since the reform and opening up,China’s degree of industrialization has risen rapidly,and the urban population has grown rapidly.In 2011,it officially surpassed the rural population,and the corresponding rural labor force has also decreased.The rural land has been idle.The degree of intensification continues to increase.Intensive agriculture has led to the rapid development of pesticide machinery,showing a trend of diversification and intelligence,but there are problems such as drip,drift,and excessive application of pesticides.Therefore,intensive agriculture also has further requirements for pesticides.For example,more efficient,low-toxic and low-pollution pesticides.In addition,the diseases caused by fungi,bacteria and viruses have the characteristics of short reproduction cycle and fast spreading speed,so it is urgent to develop new pesticides to deal with them.Therefore,the development of pesticides with new structures and new mechanisms through organic synthesis is the key to the green and efficient development of agriculture.Quinoxaline compounds are a class of heterocyclic compounds with important application values.Amino acid receptor antagonists,plant growth regulators,antibacteria,anticoagulants,hypoglycemic agents,herbicides,fluorescent probes and dye intermediates and many other fields.Quinoxaline and its derivatives are also an important class of intermediates,which can be used as a basic skeleton to synthesize more biologically active compounds.Therefore,it has attracted the attention of researchers in organic synthesis,medicine,pesticides,etc.,and a lot of researches have been done on it and its derivatives.At the same time,the presence of fluorine in many pesticides and drugs is very common.The introduction of fluorine-containing groups into organic molecules can significantly improve the bioavailability,lipophilicity and metabolic stability of drugs.In this paper,using substituted phenylenediamine and ethyl glyoxylate and various halogenated hydrocarbons as raw materials,14 quinoxaline-2(1H)-one derivatives at position 1 and position 3 unsubstituted were synthesized,26 quinoxaline-2(1H)-one derivative at position 1 substituted and unsubstituted at position 3 were synthesized.Combine the above two quinoxaline-2(1H)-one derivatives with three reagents of trifluoromethyltrimethylsilane,[bis(difluoroacetoxy)iodo]benzene and ethyl bromodifluoroacetate By reaction,39 quinoxaline-2(1H)-one derivatives with 3 fluorine substitutions were synthesized.The structure of some target products was characterized by nuclear magnetic resonance,melting point and mass spectrometry.At the same time,we measured the antibacterial primary screening activity of the target product against Rhizoctonia solani,Botrytis cinrea,Cucumber anthrax,Gibberella zeae,Alternaria solani,Alternaria leaf spot.The results of the initial activity test showed that the series of compounds had different degrees of inhibitory activity against the six tested pathogens.Overall,the compounds had better efficacy against Rhizoctonia solani,and the inhibition rate of 20 compounds exceeded 50%,but none exceeded 80%.In addition,3i and 31 have a 96.8%and 90.2%inhibition rate for Alternaria solani,4c has a 100%inhibition rate against Botrytis cinerea,and 4j has an 85.2%inhibition rate for Alternaria leaf spot,In the test of the inhibition rate of the six tested strains,4j did not exceed the inhibition rate of Alternaria solani by more than 50%,and the inhibition rate of the other five strains exceeded 50%,which has the potential as a new lead compound,which is valuable for further research.