三氟羧草醚类似物的合成及除草活性.

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[d]thiazol-2-yl 5-(2-chloro-4-(trifluoromethyl)phenoxy)-2-nitrobenzoate] against monocotyledonous weeds was significantly higher than that of acifluorfen, and its EC50 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-NO2 benzoyl derivatives was significantly higher than that of 2-OCH3 analogues, and the herbicidal activity of acifluorfen benzoate derivatives against monocotyledons was significantly higher than that of benzamide derivatives. [ABSTRACT FROM AUTHOR]