Structural Modification of Saccharin Containing 2‐aminothiazole As Potential Fungicidal Agents

A series of saccharin derivatives containing 2- aminothiazole scaffold were designed, synthesized, and characterized by H-1 NMR, C-13 NMR, and HRMS. The fungicidal activities of these novel compounds against Botrytis cinerea, Curvularia lunata, and Rhizoctonia solani were evaluated. The results indicated that N-(4-((1,1-dioxido-3-oxobenzo[d]isothiazol-2(3H)-yl) methyl) thiazol-2-yl) acrylamide (HST3) displayed potential fungicidal activities against C. lunata, and R. solani with IC50 values of 15.0 mg/L and 12.9 mg/L respectively, which possessed higher fungicidal activity than commercial products hymexazol and amicarthiazol. Moreover, N-(4-((1,1-dioxido-3-oxobenzo[d]isothiazol-2(3H)-yl) methyl) thiazol-2-yl)-4-methoxybenzamide (HST9) possessed an IC50 value of 1.1 mg/L against B. cinerea, superior to hymexazol, amicarthiazol, and carboxin. Besides, the superficial structure-activity relationship was discussed. Furthermore, molecular docking result suggest that SDH enzyme might be one of the action targets of title compounds.