Abstract:
Three series of twenty new acifluorfen analogues were designed and synthesized using methyl 2,5-dihydroxybenzoate and acifluorfen as starting materials. Their structures were characterized by
1H NMR and
13C NMR. The herbicidal activities of the compounds were determined by methods of petri dish and greenhouse potted. The results showed that the herbicidal activity of compound
III-02 6-methylbenzo
dthiazol-2-yl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoate against monocotyledonous weeds was significantly higher than that of acifluorfen, and its EC
50 values were 2.03, 0.93 μg/mL and 1.49, 0.52 μg/mL against the roots and stems of
Echinochloa crusgalli and
Digitaria sanguinalis, respectively. Additionally, at the dosage of 100 g a.i./ha, the efficacy of compound
III -02 against monocotyledonous weeds
E. crusgalli,
S. sanguinalis and
Setaria viridis was above 85%, which was significantly higher than that of acifluorfen, and a 100% control effect on broadleafs
Portulaca oleracea,
Amaranthus retroflexus and
Abutilon theophrasti. The structure-activity relationship showed that the herbicidal activity of 2-NO
2 benzoyl derivatives was significantly higher than that of 2-OCH
3 analogues, and the herbicidal activity of acifluorfen benzoate derivatives against monocotyledons was significantly higher than that of benzamide derivatives.