Lian He

Synthesis and fungicidal activities of novel bis(trifluoromethyl)phenyl-based strobilurins.

Strobilurins have become one of the most important classes of agricultural fungicides. To search for novel strobilurin compounds with unique biological activities, novel bis(trifluoromethyl)phenyl-based strobilurin analogues were synthesized by the reaction of 1-bis(trifluoromethyl)phenyl based methanone oxime with corresponding strobilurin pharmacophores in the presence of bases such as potassium hydroxide, potassium carbonate, or sodium hydride. ( E)-Methyl 2-(2-(((( Z)(1-(3,5-bis(trifluoromethyl) phenyl)-1-methoxymethylidene)amino)oxy)methyl)phenyl)-3-methoxyacrylate and ( Z)-methyl- N-( E)-2-(( E)-(5,6-dihydro-1,4,2-dioxazin-3-yl)(methoxyimino)methyl)benzyloxy-3,5-bis(trifluoromethyl)benzimidate were more effective against Erysiphe graminis and sphaerotheca fuligine than commercial strobilurin fungicides metominostrobin, azoxystrobin, and trifloxystrobin.

Syntheses and fungicidal activities of thiazole-5-carboxanilides bearing thioether group

In an attempt to find leading thiazole carboxanilides exhibiting fungicidal activities, we designed and synthesized a new series of 2-sulfursubstituted thiazole carboxanilides via the reaction between 2-sulfur substituted thiazole carboxylic acid chlorides and substituted aniline. The fungicidal activities of the title compounds against Rhizoctonia solani were screened and the results were remarkable. The most potent compound 8i, N-[2,6-dichloro-4-(trifluoromethyl)phenyl]-2-methylthio-4-(trifluoromethyl)thiazole-5-carboxamide, was identified. The fungicidal EC50 of compound 8i against Rhizoctonia solani was 1.28 mg/L, being comparable to that of Thifluzamide. The results indicate that compound 8i can be considered as a lead compound for further research.