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 1H NMR, 13C 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. 18 novel saccharin derivatives bearing 2‐aminothiazole were designed and synthesized. Further fungicidal activities of the target compounds were evaluated. Compounds HST3 displays satisfied fungicidal activity against C,lunata with IC50 of 15.0 mg/L. Compound HST9 displays satisfied fungicidal activity against B. cincerea with IC50 of 1.1 mg/L.