PRODUCTION OF OPTICALLY ACTIVE 2-METHYLPIPERAZINE

摘要

PURPOSE:To readily obtain the subject compound useful as an intermediate for synthesis of medical drugs such as a quinolone-based antibacterial agent in high yield at a low cost by optically dissolving (RS)-2-methylpiperazine using an optically active N-substituted dicarboxylic acid. CONSTITUTION:An optically active N-substituted dicarboxylic acid represented by the formula ((n) is 1-2; R is acetyl, benzoyl, benzenesulfonyl or p- toluenesulfonyl) is used as an optical resolution agent and brought into contact with (RS)-2-methylpiperazine in a solvent such as methanol. The resultant mixture solution is subsequently cooled and/or concentrated to deposit sparingly soluble diastereomer salts and the residual mother liquid is cooled after concentration or without any treatment to deposit readily soluble diastereomer salts. As the N-substituted dicarboxylic acid as the resolution agent, N-acetylglutamic acid, etc., are exemplified and used in an amount of 0.1-1.5mol based on 1mol (RS)-2-methylpiperizine.