Chiral Selector Extraction Split Several Pyrethroid Intermediates Enantiomers

The optically active pesticides are highly efficient,few amount usage,more secure to crops and the environment and more competitive in the market.It has aroused widespread public concern,the separation of optically active intermediates of pesticides and enantiomers,has been into a modern industry research study hot spots.In this paper, Lambda-cyhalothric acid,trans-permethrinic acid and fenvaleric acid enantiomers were separated by chiral extraction with synthesized L-,D-tartaric esters as chiral selector.The main contents can be summarized as follows:(1) The establishment of the analytic methodsIn reverse phase conditions,the chiral separation of Lambda-cyhalothric acid,trans-permethrinic acid and fenvaleric acid were performed on quinine alkaloid chiral stationary phases with acetonitrile and water as chiral mobile phase.The enantiomers were separated at a baseline level.Analytic methods were established.(2) The synthesis of L,D-tartaric estersA series of chiral selector L,D-tartaric esters were synthesized by refluxing L,D tartaric acid and fatty alcohol.(3) Chiral extraction of Lambda-cyhalothric acid,trans-permethrinic acid and fenvaleric acid:It has been studied the resolution of Lambda-cyhalothric acid, trans-permethrinic acid and fenvaleric acid by enantioselective extraction with tartaric esters.The distribution behavior of Lambda-cyhalothric acid,trans-permethrinic acid and fenvaleric acid enantiomers was examined in aqueous solution and organic solvent containing a chiral selector hydrophobic tartaric esters.The influences of organic solvents,length of alkyl chain of tartaric esters,pH and the concentrations of tartaric esters on the partition coefficients and separation factors were investigated.(4).At the extraction separation of the various enantiomers,it were found that the chiral extractants could recognize the object very well.The various complex formed by chiral extractants with different enantiomer have different stablity,so as to achieve the purpose of extraction separation.The paper has identified the role of the adoption of three experiments appear in an analysis of such laws.The influence of the type of organic phase,tartaric acid ester alkyl chain length,the pH value of aqueous phase on the extraction separation was very obvious,and there is a certain degree of regularity from the exploraty of the preliminary mechanism.