Ellis Trevor K, Hochla Veronica M, Soloshonok Vadim A
Department of Chemistry and Biochemistry, University of Oklahoma, Norman, OK 73019, USA.
J Org Chem. 2003 Jun 13;68(12):4973-6. doi: 10.1021/jo030065v.
An efficient, easy to scale-up method for preparing 2-aminoindane-2-carboxylic acid via two-step alkylation of a Ni(II)-complex of glycine Schiff base with 2-[N-(alpha-picolyl)amino]benzophenone (PAAP) (2b) with o-dibromoxylylene (3) is reported. The first step, monoalkylation of 2b with 3, conducted under phase-transfer conditions, gave the corresponding complex 6 in excellent chemical yield (97.2%). Without any purification the intermediate 6 was cyclized under homogeneous conditions (DMF, NaO-t-Bu) to give the product 7 in high chemical yield (93.1%). Decomposition of prepared 7 afforded the target amino acid 2-aminoindane-2-carboxylic acid (1) in 97.9% yield, along with recovery of ligand 8, which was converted back to the starting glycine complex 2b. Operationally convenient experimental procedures, mild reaction conditions, as well as high chemical and volume yields render the method practical for preparing amino acid 1 and its analogues.
报道了一种通过甘氨酸席夫碱的镍（II）配合物与2-[N-(α-吡啶甲基)氨基]二苯甲酮（PAAP，2b）与邻二溴亚二甲苯基（3）的两步烷基化反应制备2-氨基茚满-2-羧酸的高效、易于放大的方法。第一步，在相转移条件下，2b与3进行单烷基化反应，以优异的化学产率（97.2%）得到相应的配合物6。无需任何纯化，中间体6在均相条件下（DMF，叔丁醇钠）环化，以高化学产率（93.1%）得到产物7。制备的7分解得到目标氨基酸2-氨基茚满-2-羧酸（1），产率为97.9%，同时回收配体8，其可转化回起始的甘氨酸配合物2b。操作简便的实验步骤、温和的反应条件以及高化学产率和体积产率使得该方法对于制备氨基酸1及其类似物具有实用性。
