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47 条记录 (耗时 0.024 秒)

    Method of racemization of optically active tetrahydrofuran-2-carboxylic acid
    2.
    发明授权
    Method of racemization of optically active tetrahydrofuran-2-carboxylic acid 失效
    光学活性四氢呋喃-2-羧酸外消旋化的方法

    公开(公告)号：US4950772A

    公开(公告)日：1990-08-21

    申请号：US429425

    申请日：1989-10-31

    申请人： Hiroyuki Nohira ,  Shoko Takebayashi ,  Atsushi Yuzawa ,  Masami Yajima

    发明人： Hiroyuki Nohira ,  Shoko Takebayashi ,  Atsushi Yuzawa ,  Masami Yajima

    IPC分类号： C07D307/24

    CPC分类号： C07D307/24

    摘要： Disclosed is a method of racemization of optically active tetrahydrofuran-2-carboxylic acid. (+)-Tetrahydrofuran-2-carboxylic acid is useful as a side chain intermediate of the antibiotics of penem series, and is prepared by optical resolution of racemic compound. The remaining (+)-isomer should be racemized and reused as the material for further optical resolution. The racemization can be, in accordance with the present invention, carried out by heating the optically active tetrahydrofuran-2-carboxylic acid to a temperature of 100.degree. C. or higher in the presence of a strong base.

    摘要翻译： 公开了光学活性四氢呋喃-2-羧酸外消旋化的方法。 （+） - 四氢呋喃-2-羧酸可用作penem系列抗生素的侧链中间体，并通过旋光拆分外消旋化合物制备。 其余（+） - 异构体应外消旋化并重新用作进一步光学拆分的材料。 根据本发明，外消旋化可以通过在强碱存在下将光学活性四氢呋喃-2-羧酸加热至100℃或更高的温度进行。

    Process for the optical resolution of (+)-2-hydroxy-4-phenylbutanoic acid
    8.
    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

    申请人： Hiroyuki Nohira ,  Shinichi Yoshida

    发明人： Hiroyuki Nohira ,  Shinichi Yoshida

    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.

    Process for preparing optically active piperazine derivatives and Intermediates for preparation
    10.
    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

    申请人： Hisamichi Murakami ,  Shoko Satoh ,  Tadashi Tobiyama ,  Ken'ichi Sakai ,  Hiroyuki Nohira

    发明人： Hisamichi Murakami ,  Shoko Satoh ,  Tadashi Tobiyama ,  Ken'ichi Sakai ,  Hiroyuki Nohira

    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。