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    Processes and intermediates for preparing 2-substituted piperidine stereoisomers
    6.
    发明授权
    Processes and intermediates for preparing 2-substituted piperidine stereoisomers 失效
    制备2-取代的哌啶立体异构体的方法和中间体

    公开(公告)号：US5965734A

    公开(公告)日：1999-10-12

    申请号：US792661

    申请日：1997-01-31

    申请人： Sowmianarayanan Ramaswamy ,  Vikram Khetani

    发明人： Sowmianarayanan Ramaswamy ,  Vikram Khetani

    IPC分类号： C07D211/34 ,  C07B61/00 ,  C07D211/26 ,  C07D213/40 ,  C07D211/32

    CPC分类号： C07D211/34

    摘要： Processes and intermediates for preparing 2-substituted piperidines such as 2-substituted d-threo piperidines are provided. In preferred embodiments, the processes of the invention comprise the steps of reacting a 2-substituted pyridine with hydrogen in the presence of a catalyst in an alkanoic acid, and adding an alkyl alkanoate to the resulting mixture of threo and erythro 2-piperidine stereoisomers to precipitate alkanoate salts of the erythro stereoisomers preferentially with respect to alkanoate salts of the threo stereoisomers. The erythro salts then are reacted with aqueous base to form the corresponding mixture of erythro amide free bases, which are reacted with a suitable organic acid resolving agent in an alkyl alcohol solvent to form acid salts of the l-erythro stereoisomers preferentially with respect to the d-erythro stereoisomers. The 1-erythro acid salts are then reacted with aqueous base to form the 1-erythro piperidine amide free base which, in turn, is epimerized to produce the desired d-threo product by treating it in an organic solvent with an alkali metal alkoxide.

    摘要翻译： 提供了制备2-取代的哌啶类的方法和中间体，例如2-取代的d-苏式哌啶。 在优选的实施方案中，本发明的方法包括以下步骤：使2-取代的吡啶与氢在催化剂存在下在链烷酸中反应，并将烷基链烷酸酯加到得到的苏氨酸和赤式2-哌啶立体异构体的混合物中 相对于苏立立体异构体的链烷酸盐，优选赤式立体异构体的链烷酸盐沉淀。 然后将红藻酸盐与碱水溶液反应以形成相应的红酰胺游离碱混合物，其与烷基醇溶剂中的合适的有机酸拆分剂反应，以优先地形成1-赤型立体异构体的酸式盐 d-erythro立体异构体。 然后将1-赤藓酸盐与碱水溶液反应以形成1-赤型哌啶酰胺游离碱，其依次通过在碱金属醇盐的有机溶剂中处理而产生所需的d-苏糖产物。