N-杂环甲基2-(4-杂芳氧基苯氧基)丙酰胺的合成及除草活性

以2-(4-羟基苯氧)丙酸为原料,设计合成了16个新的手性N-杂环甲基2-(4-杂芳氧基苯氧基)丙酰胺化合物,其化学结构经核磁共振、色谱-质谱、红外光谱及元素分析确证.初步生物活性测定结果表明,合成的化合物在2.25×103g/ha剂量时对单子叶杂草马唐(Digitaria sanguinalis)、稗草(Echinochloa crus-galli)及狗尾草(Setaria viridis)等均具有90%以上的活性;进一步活性及作物安全性测试表明,化合物(R)-(+)-N-(6-氯吡啶-3-基)甲基]-2-4-(3-氯-5-三氟甲基吡啶-2-基氧基)苯氧基]丙酰胺(2b)的除草活性高于噁唑酰草胺,且对水稻茎叶处理安全,同时对水稻田主要杂草千金子的活性远高于氰氟草酯;化合物的除草活性与立体构型有关,R构型为活性构型.

Synthesis and Herbicidal Activity of N-Arylmethyl-2-(4-arylxoyphenoxy)propionamide

Aryloxyphenoxypropionic acid(APP) herbicides inhibiting acetyl-CoA carboxylase(ACCase) have been identified as one of the most important herbicides. As part of continuous efforts to search for new herbicides with high efficacy, broad-spectrum activity and safety to crops, the commercialized APP herbicide metamifop was used as lead compounds for further optimization. Sixteen new N-arylmethyl 2-(4-arylxoy-phenoxy) propionamide compounds were designed and prepared by multistep synthetic procedures starting from(R)-(+)2-(4-hydroxyphenoxy) propanoic acid, and their structures were characterized by 1H NMR, 13C NMR, LC/MS, IR and elemental analysis. Steric configuration was confirmed by chiral column liquid chromatography. The bioassay results indicated that all compounds exhibited >90% activity against crabgrass(Digitaria sanguinalis L.), barnyard grass(Echinochloa crus-galliL.) and green foxtail(Setaria Viridis L.) at 2250 g/ha. Further herbicidal activity and phytotoxicit to crops results indicated that(R)-(+)-N-(6-chloropyridin-3-yl)methyl] -2-(4-{3-chloro-5-(trifluoromethyl)pyridin-2-yl] oxy}phenoxy)-propanamide(2b) was more effective against Digitaria sanguinalis (IC50=15.4 g/ha) and Echinochloa crus-galli (IC50=22.8 g/ha) than metamifop(IC50=31.9 g/ha and 25.0 g/ha). In particular, compound 2b was safe to rice(Xiang zao xian 24) and more effective against Leptochloa than commercial cyhalofop-butyl. The herbicidal activity is related to steric configuration that the compounds of R configuration have more effective activity.