Design, Synthesis and Fungicidal Activity of Novel 2‐aryl‐thiazole Derivatives Containing Saccharin Motif

A series of novel 2‐aryl‐thiazole derivatives containing saccharin were designed and synthesized by a facile method, and their structures were characterized by 1H NMR, 13C NMR and HMRS. Biological tests indicated that the parts of 2‐aryl‐thiazole derivatives possess potent fungicidal activities against Sclerotinia sclerotiorum, Botrytis cinerea, and Alternaria altanata. Especially, N‐((2‐(4‐chlorophenyl)thiazol‐4‐yl)methyl)‐4‐(1,1‐dioxido‐3‐oxobenzo[d]isothia‐zol‐2(3H)‐yl)butanamide (7 p) displays inhibition rates of 49.2 % and 41.9 % at a concentration of 10 mg/L against S. sclerotiorum and B. cinerea respectively, while 2‐(1,1‐dioxido‐3‐oxobenzo[d]isothiazol‐2(3H)‐yl)‐N‐((2‐(4‐methoxyphenyl)thiazol‐4‐yl)methyl)acetamide (7 f) shows an inhibition rate of 53.3 % at a concentration of 10 mg/L against A. altanata. Furthermore, the structure‐activity relationship was discussed. It suggested that the 2‐aryl‐thiazole group can be considered as a precursor structure for further design of fungicides. A series of novel 2‐aryl‐thiazole derivatives containing saccharin fragment were designed and synthesized. Bioactivities assay of all tittle compounds were carried out. N‐((2‐(4‐chlorophenyl)thiazol‐4‐yl)methyl)‐4‐(1,1‐dioxido‐3‐oxobenzo[d]isothia‐zol‐2(3H)‐yl)butanamide (7 p) displays satisfied fungicidal activity against S. sclerotiorum and B. cincerea. 2‐(1,1‐dioxido‐3‐oxobenzo[d]isothiazol‐2(3H)‐yl)‐N‐((2‐(4‐methoxyphenyl)thiazol‐4‐yl)methyl)acetamide (7 f) displays satisfied fungicidal activity against A. altanata.