An Investigation into Formation of Impurities During Synthesis of Blonanserin

During the process development of Blonanserin (1), we have observed formations of unknown impurities are in the final product at enhanced levels which was identified as Des ethyl impurity, di-N-ethylpiperazine impurity, Chloro impurity and des-fluoro impurity. The present work involves detailed optimization studies directed toward the development of an efficient process for the commercial production of Blonanserin substantially free from the chloro impurity and other impurities.