The Design And Synthesis Of Several Benzene-4 Replacement Of Sulfonylureas

Acetolactate Synthase is the ideal target of various herbicides.Now it has been an importmant herbicides research field to design and synthesize noval highly efficeinet sulfonylurea herbicides.Sulfonylurea herbicides have the features of high-activity,good selectivity,low dosage and lowpoisonous to human beings and animals for their non-existence of AHAS in the body.However,some sulfonylurea herbicides in soil are hard to degrade,and some weeds become resistance.And it is demanded to design and synthesize new sulfonylurea herbicides which is easy to degrade and hydrolyze in the field.By studying the hydrolysis mechanism of sulfonylurea,the available sulfonylurea herbicides are designed by modifying the para-of the connection on the benzene ring,or changing with different substituents heterocyclic structure.And some noval high-activity and easily degradative sulfonylureas were synthesized.In this thesis,five new sulfonylureas compounds are sythesized,which are（1）2-（（（（（4-methoxy-6-methyl-1,3,5-triazin-2-yl）amino）ca rbonyl）amino）sulfonyl）-4-amino,methyl ester;（2）Benzoic acid,2-（（（（（（4,6-dimethoxy-2-pyrimidinyl）amino）carbonyl）amino）sulfonyl）methyl）-4-amino,ethyl ester;（3）Benzoic acid,2-（（（（（4-chloro-6-methoxy-2-pyrimidinyl）amino）carbonyl）amino）sulfonyl）-4-amino,ethyl ester;（4）Benzoic acid,2-（（（（（4-methoxy-6-methyl-1,3,5-triazin-2-yl）amino）carbonyl）amino）sulfonyl）-4-amino,ethyl estera and（5）1-（2-chlorophenyl-4-nitrosulphonyl）-3-（4-methoxy-6-methyl-1,3,5-triazin-2-yl）urea.With benzene sulfonyl chloride or benzene sulfonamide as intermediates,the synthesis paths are based on the cyanate method,the isocyanate method or the diphenyl carbonate method to produce 4-nitryl-substituted benzenesulfonylurea compounds and then get reduced with hydrogen catalysted by palladium carbon or raney nickel to make 4-amino-substituted benzenesulfonylurea compounds.After synthesis,we entrust Shanghai South Pesticide Research Center to test the herbicidal activity of sulfonyl urea compounds（2）and（3）,and the results proved that under the dose of 150 mg/L,the inhibition rate was 90% to the broadleaf grass weeds.The hydrolysis test of compound（2）and 2-NO₂ had been tested,and the compound（2）had a half-life of about 6 days,and for compound 2-NO₂ it was about 22 days,which indicated that the half-life of sulfonylurea compound with 4-NH₂ substituent on benzene ring was shorter than the sulfonylurea compound with 4-NO₂ substituent on benzene ring.