Design, synthesis and antifungal activity of novel 1,4-benzoxazin-3-one derivatives containing an acylhydrazone moiety.

A series of 1,4-benzoxazin-3-one derivatives containing an acylhydrazone moiety were designed, synthesized and evaluated for their antifungal activities against , , , , and . The structures of target compounds were characterized by H NMR, H NMR, F NMR and HRMS. The preliminary antifungal evaluation of all target compounds showed that some target compounds possessed moderate to good activities against , , and . Among them, compounds and exhibited noticeable inhibition effects against with the EC values (effective concentration for 50% activity) of 20.06 and 23.17 g/ml, respectively, which were even nearly double effective than that of hymexazol (40.51 g/ml). Meanwhile, compound displayed a notable inhibitory effect toward , with the EC value of 26.66 μg/ml, which was better than that of hymexazol (32.77 g/ml). In addition, compound yielded the EC value of 15.37 g/ml against , which was less than those of hymexazol (18.35 g/ml) and carbendazim (34.41 g/ml). Eventually, compound showed higher inhibitory effect against , with EC value of 26.76 g/ml, which was better than that of hymexazol (>50 g/ml).