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CN101333180B 一种制备左乙拉西坦中间体的方法 有权 许可

一种制备左乙拉西坦中间体的方法
摘要：
本发明公布了一种左乙拉西坦中间体(S)-α-乙基-2-氧代-1-吡咯烷乙酸的制备方法，即以(RS)-α-乙基-2-氧代-1-吡咯烷乙酸为起始原料，以(R)-α-甲基苄胺为拆分剂在拆分溶剂中拆分得到，其特征在于所述的拆分溶剂为C1～C7的酮、C1～C7醇、C1～C4酯类或以上溶剂的混合。并且，副产物(R)-α-乙基-2-氧代-1-吡咯烷乙酸在强碱作用下消旋回收可以重新得到(RS)-α-乙基-2-氧代-1-吡咯烷乙酸。本发明较以往专利优点在于，化合物(RS)-α-乙基-2-氧代-1-吡咯烷乙酸拆分时所选用溶剂拆分效率高，并且毒性小，拆分盐只需精制一次即可使(S)-α-乙基-2-氧代-1-吡咯烷乙酸的光学纯度达到满意要求([α]20D＝-25.0±1°(C＝1，丙酮))。另外化合物(R)-α-乙基-2-氧代-1-吡咯烷乙酸的消旋回收不仅能够减少环境的污染并且能降低产品的成本。
摘要（英）：

The invention discloses a preparation method for a levetiracetam intermediate (S)-alpha-ethyl-2-oxo-1-pyrrolidine acetic acid, which takes (RS)-alpha-ethyl-2-oxo-1- pyrrolidine acetic acid as the starting material and takes (R)-alpha-methyl benzylamine as resolving agent to get the product through resolving in resolving solvent. The invention is characterized in that the resolving solvent can be C1-C7 ketones, C1-C7 alcohols, C1-C4 esters or the mixture of the solvents. In addition, the by-product (R)-alpha-ethyl -2 - oxo -1 - pyrrolidine acetic acid can be recovered through racemization under the effect of alkali so as to regain the (RS)-alpha-ethyl -2-oxo-1- pyrrolidine acetic acid. Compared with the existing invention, the preparation method of the invention has the advantages that during resolving, the solvent selected for the compound (RS)-alpha-ethyl -2-oxo -1 - pyrrolidine acetic acid has high resolving efficiency and small toxicity; the resolving salt only needs to be refined once, so that the optical purity of (S)-alpha-ethyl -2-oxo -1 - pyrrolidine acetic acid can meet the requirement (alpha<20>D is equal to -25.0 plus or minus 1 degree (C is equal to 1, acetone)). In addition, the racemic recovery of the compound (R)-alpha-ethyl -2-oxo-1-pyrrolidine acetic acid can reduce environmental pollution and decrease the cost of the product.

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