Process for preparing optically active piperazine derivatives and
Intermediates for preparation
    1.
    发明授权
    Process for preparing optically active piperazine derivatives and Intermediates for preparation 失效
    制备光学活性哌嗪衍生物的方法和制备中间体

    公开(公告)号:US5792869A

    公开(公告)日:1998-08-11

    申请号:US552089

    申请日:1995-11-02

    IPC分类号: C07C311/19 C07D241/04

    CPC分类号: C07C311/19 C07D241/04

    摘要: Process for preparing optically active 2-piperazine-carboxylic acid derivatives, particularly S-enantiomer thereof, in high yield and high optical purity on industrial scale. As the optical resolving agents, easily accessible sulfonamides derived from selected optically active amino acids, such as N-tosyl-L-phenylalanine, N-tosyl-D-phenylglycine, N-tosyl-L-alanine or N-tosyl-L-valine, give excellent results. These resolving agents are stable and easily recovered from the reaction mixture and reused. Resolved 2-piperazinecarboxylic acid derivatives are preferably isolated as 4-t-butoxycarbonyl (Boc) derivatives. Diastereomeric salts (an example being shown below) formed as the intermediates of resolution are novel. ##STR1## �In the formula "Ar" stands for a phenyl or naphthyl group which may be substituted with one to three C1-C6 alkyl groups, halogen atoms, nitro or alkoxy groups; and n=0 or 1.!

    摘要翻译: 以高产率和高光学纯度在工业规模上制备光学活性2-哌嗪 - 羧酸衍生物,特别是S-对映异构体的方法。 作为光学拆分剂,可以使用衍生自N-甲苯磺酰基-L-苯丙氨酸,N-甲苯磺酰基-D-苯基甘氨酸,N-甲苯磺酰基-L-丙氨酸或N-甲苯磺酰基-L-缬氨酸等选择旋光氨基酸的容易获得的磺酰胺 ,效果很好。 这些拆分剂稳定并容易从反应混合物中回收并重复使用。 优选分离出2-哌嗪羧酸衍生物作为4-叔丁氧基羰基(Boc)衍生物。 作为分辨率的中间体形成的非对映异构体盐(以下示出的实施例)是新颖的。 [式中,“Ar”表示可被一至三个C 1 -C 6烷基,卤原子,硝基或烷氧基取代的苯基或萘基; 并且n = 0或1。

    Process for the optical resolution of (+)-2-hydroxy-4-phenylbutanoic acid
    7.
    发明授权
    Process for the optical resolution of (+)-2-hydroxy-4-phenylbutanoic acid 失效
    光学拆分(+) - 2-羟基-4-苯基丁酸的方法

    公开(公告)号:US4904822A

    公开(公告)日:1990-02-27

    申请号:US307948

    申请日:1989-02-09

    IPC分类号: C07C51/487

    CPC分类号: C07C51/487

    摘要: A process for the optical resolution of (.+-.)-2-hydroxy-4-phenylbutanoic acid which comprises treating (.+-.)-2-hydroxy-4-phenylbutanoic acid with an optically active 1-(p-tolyl)ethylamine or an optically active N-(2-hydroxy)ethyl-.alpha.-methylbenzylamine as a resolving agent is provided by the present invention.According to the invention, (-)-2-hydroxy-4-phenylbutanoic acid, which is useful as a starting substance for the synthesis of angiotensin converting enzyme-inhibiting pharmaceuticals, can especially be obtained in a highly pure state and in a high yield.