N -(噻唑-2-基)-2-[4-(芳氧基)苯氧基]丙酰胺的合成、晶体结构与除草活性

Eighteen N-(thiazol-2-yl)-2-(4-aryloxyphenoxy)propionamides were synthesized by reaction of (R)-(+)-2-(4-hydroxyphenoxy)propanoyl chlorides with 2-aminothiazole derivatives. Their structures were confirmed by H NMR, C NMR, elemental analysis, EI-MS and optical rotation. The crystal structure of (R)-N-(4-trifluoromethyl-5-ethoxycarbonylthiazole-2yl)-2-[4-(3-fluoro-5-chloropyridin-2-yl)oxy)phenoxy)propionamide was determined by X-ray diffraction analysis. The crystal belonged to the tetragonal system, space group P41212 with a=14.45502(18) A, b=14.45502(18) A, c=21.7813(5) A; Z=8, V=4551.14(15) A, Dc=1.558 Mg/m, F(000)=2176, μ=3.013 mm , and the final R=0.0302, wR=0.0687. The bioassay results indicated that most of title compounds displayed moderate to excellent herbicidal activity against crabgrass (Digitaria sanguinalis) and barnyard grass (Echinochloa crusgalli.) at the dose of 1500 g/hm. Some compounds showed 100% inhibition against the growth of the crabgrass and barnyard grass when applied at the pre-emergence and post-emergence treatment.