Synthesis,Fungicidal Activity,and Sar Of 2-Substituted Amino-2-Phenylethane-Sulfonamides

In order to find sulfonamide fungicides with potential for commercialization,this paper refered to the active structure of alkylamines of 2-substituted alkylaminocycloalkylsulfonamide compounds of previous generations,choiced the N-(2-Trifluoromethyl-4-chlorophenyl)-2-phenyl-2-oxoethanesulfonamide as the lead compound,Reductive amination of carbonyl,The chain alkyl group,the substituted benzyl group and the substituted phenylethyl group were introduced respectively.On the basis of the phenylethyl series,the aniline on the sulfonamido group was transformed into trifluoroethylamine,and the second phenyl group was transformed into 3,5-difluorophenyl.Five series(linear alkyl series,substituted phenylethylamine series,substituted benzylamine series,trifluoroethylamine series,3,5-difluorophenyl Series)of 52 2-substituted alkylamino-2-substituted phenylthanesulfonamides were designed and synthesized.The structures of all the compounds were identified by 1H NMR and MS.Among them,the structure of compound FZH-11 was confirmed by X-ray single crystal diffraction(CDCC:1917473).The fungicidal activity was systematically evaluated by germicidal spectrum test,in vitro germicidal activity test,spore germination inhibition test and in vivo pot experiment.The in vitro activity measurement of the compounds on pathogenic fungi showed that all the compounds in this series had certain effects on six pathogenic fungi(Botrytis cinerea,Sclerotinia sclerotiorum,Phyricularia grisea,Phytophthora capsici,Fusarium graminearum,and Rhizoctonia solani Kuhn.The inhibitory effect showed good inhibitory activity against B.cinerea,S.sclerotiorum,and P.grisea.The average inhibitory rates against the three pathogenic fungi were 61.60%,68.96%,and 50.57%,respectively.In the results of the in vitro activity determination of S.sclerotiorum,FZH-10,FZH-17,FZH-18 The inhibitory activities of five compounds,FZH-20 and FZH-52 exceeded 90%.Based on the results of the fungicidal spectrum research,we took the tomato B.cinerea and S.sclerotiorum as the main control objects and determined their EC50 values.The results showed that in the EC50 determination of B.cinerea,there were 20 compounds with an EC50 below 10?g mL-1,the compound FZH-18 had the lowest EC50 against B.cinerea,which was only 2.11?g mL-1,which exceeds the control agents boscalid and SYP-Z048(ECso:3.2?g mL-1,3.01?g mL-1).In S.sclerotiorum,the EC50 values of 14 compounds in this paper reached below 10 ?g mL-1,which was lower than that of the control agent,boscalid(EC50=11.04?g mL-1).In addition,the EC50 of the six compounds FZH-10,FZH-17,FZH-18,FZH-48,FZH-51,and FZH-52 were below 5?g mL-1,and the EC50 were 4.29?g mL-1 and 4.31?g mL-1,4.03?g mL-1,4.5?g mL-1,4.74?g mL-1,2.32?g mL-1.Among them,FZH-52 had the lowest EC50 that is 2.32?g mL-1.The results of the inhibition test of spore germination of B.cinerea showed that:The results showed that 11 compounds had no inhibitory effect on spore germination.When we increased the concentration of the agent to 50?g mL-1,almost all the agents showed different degrees of inhibition,and the inhibition rate of some of the better active compounds was distributed between 40%and 60%,of which FZH-37 Shows the best inhibition effect,and its inhibition effect was only 63.88%.None of them achieved the inhibitory activity of the control agent boscalid.After the in vitro fungicidal activity of the two pathogenic bacteria was measured,the control effects on B.cinerea and S.sclerotiorum were measured on live tomato seedlings and rape seedlings,respectively.In vivo tests,except for two compounds of this series,FZH-11 and FZH-19,had no effect on B.cinerea in pots of live tomatoes,and the other compounds showed different degrees of inhibition.The control effect of 25 compounds on B.cinerea exceeded that of the control agent Pythium radiata(control effect was 53.31%).Among them,FZH-52 had the highest control effect,reaching 82.17%,which was comparable to that of the control agent,boscalid(81.02%).In the test of controlling rapeseed sclerotinia disease with live rapeseed seedlings,except for compounds FZH-8,FZH-33,and FZH-47,all other compounds in this series had a certain degree of control effect on S.sclerotiorum.The control effect was almost arranged from 40%to 60%,and a total of 24 compounds fall within this range.The control activity of FZH-26 and 36 was more than 80%,of which FZH-26 had the highest control effect,reaching 84.91%,which exceeds the control agent procymidone.79.87%,and compared with Boscalid(100%control effect),There was still a certain gap.Based on the results of fungicidal activity measurement,the relationship between the structure of this series of 2-alkyl-substituted amino-2-substituted phenylethanesulfonamide compounds and their biological activity was summarized.In the alkyl series,when the linear chain reaches five,the compound had the highest inhibitory effect on pathogens,and the activity of the compounds decreases as the carbon chain lengthens or shortens.At the same time,in comparing the structure and activity relationship of phenylethylamine series,When the substituent of benzene ring is electron donor or electron acceptor,the activity of B.cinerea and S.sclerotiorum is not affected much.When the substituent position changes,the inhibition effect of 3-substituent on the two pathogenic fungi is higher than that of other positions,whether in vitro or in vivo.Among the substituted benzylamine compounds,4-substituted compounds had the best inhibitory effect on B.cinerea.But for S.sclerotiorum,except for the compound FZH-26,which had a fluorine atom at the fourth position of the benzylbenzene ring,the structure of the remaining compounds has no obvious relationship with the control effect;In the trifluoroethylamine series,In addition to fzh-36,a leading compound with good activity,the inhibition of other compounds on all pathogenic fungi decreased.Finally,in the bioassay data of 3,5-difluorophenethyl-sulfonamide,we found that when the substituent on the phenethylphenyl group was When the electron-withdrawing group was used,its fungicidal activity was enhanced,and the activity of the substituent at the second position was better than that of other positions,and the activity of the bi-substitution was better than that of the mono-substitution.There was no significant difference in the control effect of each compound in the control effect in vivo.