Study On The Design,Synthesis And Biological Activity Of Pyrimidine-5-formyl Compounds

Pesticides play an extremely important role in agricultural production,they can eliminate weeds and control crop pests or diseases.Because they have the feature of fast,efficient and economical weed control functions,herbicides have been widely used in pesticides.Developing new herbicides which are of high efficiency,low toxicity and without cross-resistance,is one of the most important novel pesticide discovery.Heterocyclic compounds have been a hot research and development of new pesticides.Pyrimidine,as a nitrogen-containing heterocyclic compound,have unique biological activity in the field of medicine and pesticides.Pyrimidine is a important intermediate in the synthesis of medicine and pesticide,particularly in the synthesis of drug molecules.In order to find Pyrimidine precursor structure of high biological activity,we designed and synthesized substituted pyrimidinecarboxamides compounds,pyrimidine carboxylic acid ester compounds and pyrimidine formyl pyrazole compounds by combinating bioisostere principle and active substructures splicing.Moreover,FTIR,13C NMR,MS and1H NMR spectra were used to confirm the structures of the target compounds.Then the indoor petri dish method is used for herbicidal activity test.Specific content as follows:1.Overview of the PDS and HPPD enzyme structure,function and mechanism of action of inhibitors.Meanwhile,the study outlined the progress of PDS and HPPD inhibitors and progress of pyrimidine heterocyclic herbicides.2.Design and synthesis of the target compounds:(1)Design:By using bioisostere principle,pyrimidine ring was used to replace pyridine ring and 2,4-diclorobenzene ring,which were groups respectively from diflufenican and py-prazoxyfen molecular structure.Then their structure was modified by combinating active substructures splicing to generate pyrimidine formamide compounds and pyrimidine formyl pyrazole compounds.By using active substructures splicing,salicylic acid ester groups and benzyl amine groups were introduced into pyrimidine ring to generate pyrimi-dine carboxylic acid ester compounds.(2)synthesis:The raw material diethyl(ethoxymethylidene)propanedioate reacted with methanimidamide acetate to produce 4-hydroxy-5-pyrimidine carboxylic acid ethyl ester.Then the product was substituted with phosphorus oxychloride and phenol(or sodium ethoxide)followed by being amidated to generate pyrimidine formamide compounds.The intermediate 4-chloro-5-pyrimidine carboxylic acid ethyl ester was substituted with sodium ethoxide,followed by reacting with 1,3-dimethyl pyrazole ketones and substitutided 2-bromine-1-phenyl ethyl ketone compounds to obtain pyrim-idine-formyl pyrazole compounds.The intermediate 4-chloro-5-pyrimidine carboxylic acid ethyl ester reacted with Substituted phenol and substituted amine to obtain pyrimidine carboxylic acid ester compounds.4.The indoor petri dish method was used for herbicidal activity test of the target compounds.Results showed that the synthesized compounds could to a certain extent inhibit the root and stem growth of rapeseed(dicotyledonous plants)and perennial ryegrass(monocotyledon).The inhibition phenotype to rapeseed and perennial of comp-ounds 10a-10c was similar to that of mesotrione,and the inhibitory activity of them was pretty.When the concentration was 100 mg/L,compound 10a-10c could cause perennial ryegrass leaf albino rate to 100%.