Synthesis and insecticidal activity of novel dihalopropene derivatives containing benzoxazole moiety: A structure–activity relationship study

Ten dichloropropene derivatives containing benzoxazole moiety were synthesized and bioassayed in order to determine their in vivo insecticidal activity. The structures of obtained compounds were identified by 1H NMR, MS and elemental analyses. The bioassay results indicated that compound 2-(3-(2,6-dichloro-4-(3,3-dichloroallyloxy)phenoxy)propoxy)-5-(trifluoromethyl)benzo[d]oxazole (5i, R1 is trifluoromethyl, R2 is H and n is 3) had the optimal structure with best insecticidal activity against Spodoptera exigua (100%) at 1 mg/L concentration, highlighting the importance of trifluoromethyl group. The structure–activity relationship of the synthesized compounds was discussed as well.