Study On Structure Optimization And Antifungal Activity Of Phenylacetamides Containing Chiral Oxazoline

Pesticides are functional chemicals that kill insects,weed,sterilize or regulate plant growth and are very important in ensuring increased grain income.However,the increasingly severe drug resistance requires that we need to create pesticides with novel structures or mechanisms of action.This is an important issue for sustainable development.The previous work of our group confirmed that chiral 2-(2-oxazolinyl)aniline can be used as a pharmacophore,and based on mandelic acid compounds,A new type of phenylacetamide compounds was found and its prevention effect of Botrytis cinerea were better than boscalid and it is initially demonstrated the potential of such compounds as lead compounds for fungicides.This paper mainly optimizes the design of such structures in order to discover highly active and promising fungicide candidate compounds,and achieving the following results:(1)Using 2-(2-oxazolinyl)aniline and benzoyl formic acid compounds as substrates,through steglich amide condensation to obtain α-carbonyl phenylacetamide intermediate A-0,which undergoes nucleophilic addition and substitution reactions,13 α-functionalized phenylacetamide compounds were synthesized,Choosing the compound A2 with better activity to optimize the structure and 17 derivatives were synthesize,The structure of the synthesized target compounds were identified by means of nuclear magnetic resonance hydrogen spectroscopy(1H-NMR),electrospray mass spectrometry(ESI-MS),X-ray single crystal diffraction and other methods.(2)Using boscalid as a positive control,the target compounds were determined by the mycelial growth method against Rhizoctonia solani,Botrytis cinerea,Sclerotinia sclerotiorum,Phytophthora capsici,Pyricularia oryzae,and Fusarium graminearum.The results show that most of the compounds have good antibacterial activities.Compound A2 demonstrated good antifungal effect against Botrytis cinerea(with EC50 of 1.241 mg/L),Rhizoctonia solani(with EC50 of 5.892 mg/L);Compound D1 demonstrated good antifungal effect against Sclerotinia sclerotiorum(with EC50 of 1.618 mg/L);Compound D5 also have good antifungal effect against Sclerotinia sclerotiorum(with EC50 of 3.626 mg/L),Rhizoctonia solani(with EC50 of 5.225 mg/L)and Botrytis cinerea(with EC50 of 4.584 mg/L)A total of 33 phenylacetamide compounds were synthesized in this paper,and the antibacterial activity test was completed.Three compounds with better activity than the positive control boscalid were found.Compound A2 has a good control effect against Botrytis cinerea,and can be used as a fungicide candidate compound,laying a foundation for the discovery of a new chiral phenylacetamide fungicide containing chiral oxazoline.