An Efficient Synthesis of Racemic 4-Hydroxy-2-oxo-1-pyrrolidineacetamide (Oxiracetam) Using Tetramic-Acid Intermediates
作者:David D. P. Laffan、Markus Bänziger、Lauren Duc、Andrew R. Evans、John F. McGarrity、Thomas Meul
DOI:10.1002/hlca.19920750323
日期:1992.5.6
The title compund, 1a, has been synthesised in racemic form from ethyl (E)-4-chloro-3-ethoxybut-2-enoate in 43% overall yield in five steps. Several routes to the final product are described, but the most efficient involves hydrogenation of a C(5)-unsubstituted tetramic acid 5b. The instability of this class of compounds required the use of a catalyst which could operate under very acidic aqueous conditions
由(E)-4-氯-3-乙氧基丁-2-烯酸乙酯以消旋形式合成标题化合物1a,分五个步骤,总收率为43%。描述了最终产品的几种途径,但是最有效的途径涉及C(5)-未取代的四甲酸5b的氢化。这类化合物的不稳定性要求使用可以在非常酸性的水性条件下运行的催化剂,这种作用已被5%Ru / C催化剂成功填补。