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 1 H NMR, 13 C 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(3 H )‐yl) methyl) thiazol‐2‐yl) acrylamide ( HST3 ) displayed potential fungicidal activities against C. lunata , and R. solani with IC 50 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(3 H )‐yl) methyl) thiazol‐2‐yl)‐4‐methoxybenzamide ( HST9 ) possessed an IC 50 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.