Large scale synthesis of N-benzyl-4-formylpiperidine through partial reduction of esters using aluminum hydride reagents modified with pyrrolidine
作者:Taichi Abe、Toyokazu Haga、Shigeto Negi、Yukio Morita、Keizou Takayanagi、Kimio Hamamura
DOI:10.1016/s0040-4020(01)00143-0
日期:2001.4
The modification of sodium bis(2-methoxyethoxy)aluminum hydride (SMEAH) with pyrrolidine provided a highly selective reducing agent to transform N-benzyl-4-ethoxycarbonylpiperidine into N-benzyl-4-formylpiperidine 1 under mild conditions. However, this simple modification led to a significant amount of N-benzyl-4-(pyrrolidin-1-ylmethyl)piperidine 4 due to overreduction of an intermediate. Our extensive
用吡咯烷对双(2-甲氧基乙氧基)氢化铝钠(SMEAH)的改性提供了一种高选择性的还原剂,可在温和条件下将N-苄基-4-乙氧基羰基哌啶转化为N-苄基-4-甲酰基哌啶1。然而,由于中间体的过度还原,这种简单的修饰导致大量的N-苄基-4-(吡咯烷-1-基甲基)哌啶4。我们广泛的研究表明,碱性碱如叔碳酸钾-丁醇可以抑制副产物的生成,从而提供所需的醛,这使我们能够为盐酸多奈哌齐的关键中间体建立可行的合成方法。还描述了该试剂的潜在应用。