作者:Timothy L. Stuk、Bryce K. Assink、Ronald C. Bates,、David T. Erdman、Victor Fedij、Sandra M. Jennings、Jennifer A. Lassig、Randy J. Smith、Traci L. Smith
DOI:10.1021/op034060b
日期:2003.11.1
The compound (+)-2-(7-chloro-1,8-naphthyridin-2-yl)-3S-(5-methyl-2-oxohexyl)-1-isoindolinone (pagoclone) shows anxiolytic activity due to partial agonism of the benzodiazepine site of the GABA(A) receptor. We describe the development of an economical and practical process for a 100+ kg pilot plant production used to supply development needs. For the key reaction, a beta-keto phosphonium salt was prepared by selectively reacting a primary alpha-bromo ketone with triphenylphosphine in the presence of a secondary alpha-bromo ketone. A novel Wittig reaction with a 1-isoindolinone was used to produce racemic pagoclone. The enantiomerically pure drug substance was prepared by hydrolyzing a gamma-lactam and resolving the resulting enantiomeric carboxylic acids with (+)-ephedrine hemihydrate. An alternate resolution, involving chiral multicolumn chromatography (MCC) was also developed. The synthesis was completed by a racemization-free lactam formation to afford pagoclone.