PROBLEM TO BE SOLVED: To provide an improved method for synthesizing ivabradine by using specific operational conditions.SOLUTION: The method comprises the following process: 3,4-dimethoxyphenylacetic acid is converted to a compound of formula (V) (wherein groups R1 and R2 are each a straight-chain or branched-chain 1-6C alkoxy group, or forms a ring by being bound to each other together with carbon atoms born thereon), which is then put to cyclization reaction in an acidic medium to obtain a compound of formula (I), which is then put to N-alkylation followed by reductive amination to effect conversion to the objective ivabradine.COPYRIGHT: (C)2010,JPO&INPIT【課題】イバブラジンの改良合成法の提供。【解決手段】3,4-ジメトキシフェニル酢酸を式(V)[式中、基R1およびR2は、直鎖もしくは分枝鎖C1~C6アルコキシ基を表すか、またはそれらを担持する炭素原子と一緒になって、環を形成する]で表される化合物に変換し、これを、酸性媒体中で環化反応に付して、式(I)で表される化合物を得、N-アルキル化、還元的アミノ化でイバブラジンに変換する。【選択図】なし
