A Practical Synthesis of (S)-(-)-Nadifloxacin: Novel Acid-Catalyzed Racemization of Tetrahydroquinaldine Derivative.
作者:Koji HASHIMOTO、Yoshihiko OKAICHI、Daisuke NOMI、Hisashi MIYAMOTO、Masahiko BANDO、Masaru KIDO、Tsutomu FUJIMURA、Takuya FURUTA、Jun-ichi MINAMIKAWA
DOI:10.1248/cpb.44.642
日期:——
(S)-(-)-Nadifloxacin [(S)-(-)-9-fluoro-6, 7-dihydro-8-(4-hydroxy-1-piperidyl)-5-methyl-1-oxo-1H, 5H-benzo[i, j]quinolizine-2-carboxylic acid, (S)-(-)-OPC-7251], an antibacterial agent, was synthesized from (S)-(-)-5, 6-difluoro-2-methyl-1, 2, 3, 4-tetrahydroquinoline (DFTQ), which was prepared by the optical resolution of recemic DFTQ with 2, 3-di-O-benzoxyl-L-tartaric acid. Racemization of the undesired enantiomer [(R)-(+)-DFTQ] was studied in the presence of various acids and the best result was obtained in the case of methanesulfonic acid. The absolute configuration of (-)-nadifloxacin was determined as S by X-ray crystallographic analysis.
(S)-(-)-那氟沙星[(S)-(-)-9-氟-6, 7-二氢-8-(4-羟基-1-哌啶基)-5-甲基-1-氧代-1H, 5H-苯并[i, j]喹嗪-2-羧酸,(S)-(-)-OPC-7251]是一种抗菌剂、由 (S)-(-)-5,6-二氟-2-甲基-1,2,3,4-四氢喹啉 (DFTQ)合成,DFTQ 是用 2,3-二-O-苯并氧酰基-L-酒石酸对受体 DFTQ 进行光学解析制备的。在各种酸的存在下研究了非期望对映体[(R)-(+)-DFTQ]的消旋化,在甲磺酸的情况下获得了最佳结果。通过 X 射线晶体学分析,确定 (-)-nadifloxacin 的绝对构型为 S。