高效旋光性除草剂敌草强的研究

RESEARCH ON HIGH OPTIC ITY OF R(-)NAPROPAMIDE HERBICIDE

敌草强〔R(-)Napropamide〕是一种新型的高效旋光性除草剂.它以α-萘酚、α-氯丙酸和二乙胺为原料,合成α-(1-萘氧基)丙酸和 N,N-二乙基-2-(1-萘氧基)丙酰胺,分别用成盐拆分法和优先结晶法制得.经 HPLC 检测,光学纯度>98%.红外光谱和核磁共振谱鉴定,与分子结构相符.盆栽和大田试验表明,左旋体的药效是右旋体的8倍,是一般工业品的1.7～2倍.

This paper reports a method for preparation and identification of the optical isomers ofnapropamide herbicide.Napropamide synthesized from the same chemicals of α-naphthol,α-choropropinonic acid anddiethylamine as used in industrial manufacture was effectively resolved by optical reagents and preferentialcrystallization,yielding two optically active isomers,R(-)napropamide in our laboratory.The optical purities identified by HPLC were higher than 98%.The chemical structure of these twoisomers were identified by IR and NMR(IR:(KBr)1627 cm^-1(c=0);NMR:(CCL_4)1.00(3H,methyl),1.60～1.70(6H,methyl),3.35(4H,methylene),5.00(IH,methine),6.70～8.40(7H,aro-matic).The bioassay indicated that the efficiency of R(-)-napropamide for killing barn-grass is 8 times that ofL(+)-isomer and 1.7～2 times of the racemic component.