Stereoselective synthesis of cis and trans n-tosyl sulphilimines and sulphoxides from 2-alkylthianes and 2-alkylthiolanes assignments of configurations
thiolane derivatives with 2-methyl, 2-ethyl, 2-isopropyl and 2-tert-butyl groups were prepared and converted to cis and trans sulphilimines and sulphoxides by various stereoselective methods. Cis-sulphilimines were formed by using t-BuOCl and TsNH- in a two-stage process, while cyclic sulphides were converted by chloramine-T predominantly to trans-sulphilimines. Sulphoxides enriched in cis and trans isomers
制备具有2-甲基,2-乙基,2-异丙基和2-叔丁基的噻吩和硫杂环戊烷衍生物,并通过各种立体选择性方法将其转化为顺式和反式亚硫亚胺和亚砜。顺式sulphilimines通过使用T-BuOCl和TsNH形成-在一个两阶段过程,而环状硫化物通过氯胺-T主要转化成反式- sulphilimines。通过不同的氧化方法获得了富含顺式和反式异构体的亚砜。通过hplc测量非对映异构产物分布,并通过13 C NMR光谱法确定非对映异构体的构型。通过分析13 C NMR和X射线数据确定了亚砜亚胺的优选构象。如图13所示在13 C NMR光谱中,亚硫亚胺和亚砜的构型是相似的。
PROCESS FOR PREPARING AMIC ACID ESTERS
申请人:——
公开号:US20030032667A1
公开(公告)日:2003-02-13
The present invention aims at providing a process for producing an amic acid ester useful as an intermediate for agrochemical, easily at a low cost industrially.
The present invention provides a process for producing an amic acid ester represented by the following general formula (7):
1
(wherein A is a substituted or unsubstituted lower alkylene group or the like; R
1
is a substituted or unsubstituted lower alkyl group or the like; and R
3
is a hydrogen atom or a lower alkyl group), which process comprises reacting, in the presence of water, an amino acid represented by the following general formula (1):
2
(wherein A has the same definition as given above) with a halogenated carbonic acid ester represented by the following general formula (2):
3
(wherein R
1
has the same definition as given above and X is a halogen atom) to form an amide compound represented by the following general formula (3):
4
(wherein A and R
1
have the same definitions as given above), then reacting the amide compound with a halogenated carbonic acid ester represented by the following general formula (4):
5
(wherein R
2
is a substituted or unsubstituted lower alkyl group or the like; and X is a halogen atom) to form, in the system, a mixed acid anhydride represented by the following general formula (5):
6
(wherein A, R
1
and R
2
have the same definitions as given above), and reacting the mixed acid anhydride with an amine compound represented by the following general formula (6):
7
(wherein R
3
has the same definition as given above and Het is a substituted or unsubstituted heterocyclic group).