手性镧系位移试剂核磁共振法测定芳氧丙酸酯类除草剂对映体纯度

Chiral Lanthanide Shift Reagent-Nuclear Magnetic Resonance Method for Determination of Enantiomeric Purity of Arylphenoxypropionate Herbicides

以Eu(hfc)3和Pr(hfc)3为手性镧系位移试剂(CLSR),比较了两种CLSR对2,4-滴丙酸甲酯的1HNMR和13C NMR谱手性分离效果,结果表明:Pr(hfc)3比Eu(hfc)3对手性中心相连的甲基具有更好的手性分离效果。首次应用Pr(hfc)3测定了盖草能、稳杀得和喹禾灵3种手性芳氧丙酸酯类除草剂的1HNMR和13CNMR谱,其1HNMR谱分离度R约为1,盖草能和喹禾灵的13C NMR谱分离度R大于1.5,说明1H NMR和13CNMR谱手性分离效果适用于对映体纯度测定。与手性色谱法相比,CLSR-NMR法测定对映体纯度具有操作简便、分析速度快的显著优势。

The chemical shift non-equivalence in ^1H and ^13C nuclear magnetic resonance （NMR） of dichlorprop-methyl were compared by using Eu-heptafluorohydroxy-methylene-d-camphorato （hfc）3 and Pr （hfc）3 as chiral lanthanide shift reagents （CLSR）, it showed that Pr（hfc）3 was more effective than Eu （hfc）3. Pr（ hfc）3 was used as firstly in detecting the chemical shift non-equivalence of ^1H and ^13C NMR of three arylphenoxypropionate herbicides, quizalofop-ethyl, halxoyfop-etotyl and fluazifop-butyl. The result showed that the chiral resolutions ^13C NMR of quizalofop-ethyl and ^1H NMR and ^13C NMR are fit fo of IH NMR of three herbicides were about 1, and the chiral resolutions of halxoyfop-etotyl were more than 1.5. That means the chiral resolutions of r determining the enantiomeric purity. CLSR-NMR method is simpler and faster than chiral chromatographic method in the determination of the enantiomeric purity.