脒类化合物的传统合成方法以酰胺法、腈的氨解法和原甲酸酯法为主。
1·Screening for 2 - bromo-butyric acid as the starting material, after ammonolysis, esterification, ester amine solution, split, five-step cyclization reaction Levetiracetam.
筛选以2 -溴代丁酸为起始原料，经氨解，酯化，酯胺解，拆分，环合五步反应制得左乙拉西坦。
2·Levetiracetam was prepared from L-methionine via reduction-dethiomethylation, esterification, ammonolysis, amidation and intramolecular cyclocondensation reaction with 44.6% overall yield.
以蛋氨酸为原料经还原脱硫甲基化、 酯化、 氨解、 酰胺化及分子内缩和成环4步反应合成得到了左乙拉西坦，总收率44.6%。
3·Screening for 2 - bromo- butyric acid as the starting material, after ammonolysis, esterification, ester amine solution, split, five-step cyclization reaction Levetiracetam.
筛选以2-溴代丁酸为起始原料，经氨解，酯化，酯胺解，拆分，环合五步反应制得左乙拉西坦。