| 摘要 |
<p>PURPOSE: A process for preparing optically active 5,6-dioxopiperazine-2-carboxylic acid derivatives is provided, thereby improving the preparation yield and purity of optically active 5,6-dioxopiperazine-2-carboxylic acid derivatives by using methylchlorooxoacetate. CONSTITUTION: The process for preparing optically active 5,6-dioxopiperazine-2-carboxylic acid derivatives represented by formula (1) comprises the steps of: (a) reacting optically active compounds of formula (2) with methyl chlorooxoacetage in the presence of base; and (b) reducing the reaction product of step (a) by introducing hydrogen gas in the presence of Pd/C, wherein R1 is an amino protecting group and R2 is a carboxylic acid protecting group; the base is triethylamine, pyridine, N,N-diisopropylethylamine or lutinin; and the compounds of formula (2) are prepared by reacting compounds of formula (3) with azide salt in the presence of AlCl3 or hydrates thereof.</p> |
