Abstracto

Synthesis and spectral characterization of potential impurities of solifenacin succinate

Ramadas Chavakula, M.Narayana Rao, M.Vijaya Raju, R.V.Nageswara Rao

During the process development of solifenacin succinate (5). Three stereoisomeric impurities (1-3) and one n-oxide impurity (4) with respect to solifenacin succinate were detected by reported method of simple reverse phase high-performance liquid chromatograpjy (HPLC). Three 1-3 have been prepared by the known synthetic method. To the best of our knowledge, impurity (4) had not been isolated or synthesized as pure substance until now. The new synthesis, characterization of impurity (4) was discussed. The1H and 13C NMR data of impurity (4) and solifenacin succinate 5 were reported in this paper for the first time. Based on the spectral data, the structure of these impurities (1-4) were characterized as (3S)-1-Azabicyclo[2.2.2]octan-3-yl(1S)-1-phenyl-3,4-dihydro-1Hisoquinoline- 2-carboxylate butanedioic acid (1), (3R)-1- Azabicyclo[2.2.2]octan-3-yl(1R)-1-phenyl-3,4-dihydro-1H- isoquinoline-2- carboxylate butanedioic acid 2, (3S)-1-Azabicyclo[2.2.2]octan-3-yl(1R)-1- phenyl-3,4-dihydro-1H- isoquinoline-2-carboxylate butanedioic acid 3 and (3R)-1-Azabicyclo[2.2.2]octan-3-yl(1S)-1-phenyl-3,4-dihydro-1Hisoquinoline- 2-carboxylate N-oxide (4). The synthesis, characterization of these impuritieswere discussed.