The present invention relates to an improved process for the preparation of 4-(4-Fluorophenyl)-5,6,7,8,9,10-hexahydro cyclooctane [b] pyridine-(lH)-ketone comprising the steps of hydrolyzing 4-Fluorobenzoyl acetonitrile in presence of an acid reacting with Cyclooctanone and isolating 4-(4-Fluorophenyl)-5,6,7,8,9,10-hexahydro cyclooctane [b] pyridine-(lH)-ketone. The present invention also relates to further conversion 4-(4- Fluorophenyl)-5,6,7,8,9,10-hexahydro cyclooctane [b] pyridine-(lH)-ketone into Blonanserin. The present invention also provides, process for the preparation of Blonanserin Hydrchloride and further conversion of Blonanserin Hydrchloride to pure Blonanserin.
