Synthesis And Fungicidal Activity Of 2-substituted Phenyl -2-oxo And 2-acyloxy Acetic Sulfonamide Compounds

In 2008, it was reported that 2-oxo-cycloalkyl sulfonamides had excellent fungicidal activity. Therefore,14 N-substituted phenyl-2-oxo-2-phenyl ethyl sulfonamide compounds were synthesized, and the bioassay results showed they had more excellent fungicidal activity. On this basis,80 N-substituted-2-oxo-2-phenyl aceticsulfonamides compounds were synthesized by using combinatorial chemistry method, whose structure-activity relationship of fungicidal activity was more systematic studied on N-substituted group including onmono-substituted aniline, poly-substituted aniline, substituted benzylamine and alkylamine. In order to find a series of compound of higher fungicidal activity and low toxicity, in this paper, on the basis of preliminary studies, effect of fungicidal activity on 2-substituted phenyl, 2-hydroxy and 2-acyloxy was studied and a series of new N-(2-trifluoromethyl-4-chlorophenyl)-2-oxo-2-substituted phenyl ethyl sulfonamide(Ⅲ), N-(2-ifluoromethyl-4-chlorophenyl)-2-hydroxy-2-substituted sulfonamide-phenylacetamide(IV) and N-(2-trifluoromethyl-4-chlorophenyl)-2-acyloxy-2-(3,5-difluorophenyl) ethyl sulfonamides were synthesized. These compounds had very high fungicidal activity and broad spectrum. The structure-activity relationship of the N-substituted-2-substituted phenylacetate sulfonamides was studied against Botrytis cinerea. Firstly,20 new N-(2-trifluoromethyl-4-chlorophenyl)-2-oxo-2-substituted phenyl-ethyl sulfonamide compounds were synthesized. According to structure-activity relationship between substituent on the phenyl ring and fungicidal activity,5 N-(2-trifluoromethyl-4-chlorophenyl)-2-hydroxy-2-substituted-phenyl sulfonamides compounds and 20 new N-(2-trifluoromethyl-4-chlorophenyl)-2-acyloxy-2-(3,5-difluorophenyl) ethanesulfonamide were synthesized, which were identified by’H NMR and IR.In vitro and in vivo pot experiment, the fungicidal activities of synthesized compound (III, IV, V) were measured. In vitro, the results indicated that these compounds had very high fungicidal activity against a variety of Botrytis cinerea, and inhibition rates of most of compounds were more than 80%, higher than the positive control procymidone. The highest inhibition rate reached 99.2%. From EC50 values, the fungicidal activity of the compound Ⅲ-1, Ⅲ-13, Ⅲ-15 was higher than positive control procymidone against Botrytis cinerea SY-10 (plucking from Shenyang, Liaoning Province), and relative virulence multiples were 2.1,3.9,3.3, respectively. With a control compound B-1 (N-(2- trifluoromethyl-4-chlorophenyl)-2-oxo-2-phenyl-sulfonamide) compared, the relative toxicity multiples were 3.3,6.2,5.3, respectively. The activity of 8 compounds was higher than pyrimethani against Botrytis cinerea DD-15(taken from Dandong, Liaoning Province), and relative virulence multiples were more than 13.8. In addition, the activity of 7 compounds was higher than compound B-1 against Botrytis cinerea DD-15, in which relative virulence multiples of compounds Ⅲ-2 and Ⅲ-15 were 3.6 and 3.1, respectively, compared with compound B-1. Compound Ⅳ obtained by reduction of compound Ⅲ also has a very high fungicidal activity against Botrytis cinerea. Compared with Procymidone and pyrimethanil, Fungicidal activity of compound Ⅳ-5 against DL-11 (Plucking from Dalian,Liaoning Province),relative virulence of compound Ⅳ-5 were 4.2 and 11.1. Similarly, relative virulence against HLD-15 strains were 8.0 and 12.6, respectively. In a word, Compound Ⅴ obtained from different acid chloride with the compound (Ⅳ) Docking, also has a very high fungicidal activity, generally higher than the control agent procymidone and pyrimethanil. For DL-11 strain, compared with procymidone and pyrimethanil, relative virulence were 163.3 and 431.0, in addition,for HLD-15,reached 3.2 and 5.0, respectively.Moreover, these compounds had inhibition effect against Botrytis cinerea、 thanatephorus cucumeris、PyriculariaoryaeCav、Exserohilum turcicum(Pass.)Leonard et Suggs)、Pythium aphanidermatum(Edson)Fitzpatrick)、Fusarium graminearum Schw.、 Phytophthora capsici and Corynespora cassiicola, so they can be used to control plant disease. The activity of compound Ⅲ against five kinds of pathogenic was generally higher than comparative agent B-1, compared with B-1, the highest relative toxicity reached 5.2,3.9, 2.3,1.1,1.4, respectively. Relative toxicity of compound Ⅲ against Corynespora cassiicola and Phytophthora capsici reached 5.5 and 7.7, respectively. Relative toxicity of compound Ⅳ-5 compared with B-1, against Fusarium graminearum Schw., thanatephorus cucumeris, Pythium aphanidermatum(Edson)Fitzpatrick and Corynespora cassiicola, was 1.3,1.2,2.6 and 1.0, respectively. Compared with chlorothalonil, the relative toxicities against Corynespora cassiicola and Phytophthora capsici were 5.5 and 6.2. Compared with B-1, the highest relative virulence of compound Ⅴ against 5 Pathogenic fungi were 1.7,2.2,2.4,2.6 and 1.0, respectively. Compared with chlorothalonil, the relative virulence of compound Ⅴ against Phytophthora capsici and Corynespora cassiicola were 17.1 and 5.3.