摘要
利用顺式二氯菊酸和反式二氯菊酸的溶解度不同及pKa 值的差异 ,分离二氯菊酸中的顺式体和反式体 ,可取得较好的效果 (反式二氯菊酸收率83.7 % ,顺式二氯菊酸收率88.9 % );以S( -)_α_甲基苄胺为拆分剂 ,对顺式_2,2_二甲基_3_(2 ,2_二氯乙烯基 )环丙烷羧酸酯 (俗称顺式二氯菊酯 )类杀虫剂合成中间体———顺式_2,2_二甲基_3_(2 ,2_二氯乙烯基 )环丙烷羧酸 (俗称顺式二氯菊酸 )进行拆分 ,可以得到其旋光异构体 ;其旋光异构体与S( -)_α_甲基苄胺衍生化 ,生成相应的酰胺 ;经TLC纯化后 ,以外消旋顺式二氯菊酸酰胺作为对照 ,用HPLC检测其旋光异构体的光学纯度 ;结果显示 ,顺式_R( +)_2,2_二甲基_3_(2 ,2_二氯乙烯基 )环丙烷羧酸光学纯度为93.7 % ,顺式_S( -)_2,2_二甲基_3_(2,2_二氯乙烯基 )环丙烷羧酸光学纯度为81.8% ;对反式二氯菊酸的光学纯度分析 ,可采用类似的方法 ;经顺、反分离、旋光异构体拆分获得的高效中间体 ,再进行后序合成 ,其顺反比。
Separation of trans _ dichlorochrysanthemic acid(DCCA) and cis _ DCCA was performed by using their different dissolubility and pKa value, satisfactory results were obtained with yield of 83.7% for trans _ DCCA and 88.9% for cis _ DCCA. Optical isomers of cis _ 2,2 _ dimethyl _ 3 _ (2,2 _ dichlorovinyl)cyclopropanecarboxylic acid, which is a key intermediate for the preparation of cis _ 2,2 _ dimethyl _ 3 _(2,2 _ dichlorovinyl)cyclopropanecarboxylate pesticide, were separated by using S(-) _ α _ phenylethyl amine as a derivatization reagent. Its optical and racemic isomers reacted with S(-) _α _ phenylethyl amine to form their amidates, which were purified by TLC, then determined by HPLC with a reference of the amidate of the cis _ racemic acid. The optical purity of cis _ R(+) _ and cis _ S(-) _ 2,2 _ dimethyl _ 3 _(2,2 _ dichlorovinyl)cyclopropanecarboxylic acid was 93.7% and 81.8%, respectively. Optical purity of trans _ 2,2 _ dimethyl _ 3 _ (2,2 _ dichlorovinyl) cyclopropanecarboxylic acid can be analyzed by a similar method.
出处
《分析测试学报》
CAS
CSCD
北大核心
2002年第2期25-28,共4页
Journal of Instrumental Analysis
基金
江苏省科学技术委员会开放课题
