Synthesis of 2-Acyloxycyclohexylsulfonamides and Evaluation on Their Fungicidal Activity

Eighteen N-substituted phenyl-2-acyloxycyclohexylsulfonamides (III) were designed and synthesized by the reaction of N-substituted phenyl-2-hydroxyl- cycloalkylsulfonamides (I, R(1)) with acyl chloride (II, R(2)) in dichloromethane under the catalysis of TMEDA and molecular sieve. High fungicidal active compound N-(2,4,5-trichlorophenyl)-2-(2-ethoxyacetoxy) cyclohexylsulfonamide (III-18) was screened out. Mycelia growth assay against the Botrytis cinerea exhibited that EC50 and EC80 of compound III-18 were 4.17 and 17.15 μg mL(-1) respectively, which was better than the commercial fungicide procymidone (EC50 = 4.46 μg mL(-1) and EC80 = 35.02 μg mL(-1)). For in vivo activity against B. cinerea in living leaf of cucumber, the control effect of compound III-18 was better than the fungicide cyprodinil. In addition, this new compound had broader fungicidal spectra than chlorothalonil.