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

摘要

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2.25×103 g/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.%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 herbi-cides 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 1 H NMR, 13 C 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-chloro-pyridin-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.