The present work describes an improved and highly efficient process for the synthesis of iloperidone (1), an antipsychotic agent, which is free from potential impurities. The synthesis comprises N-alkylation of 1-(4-(3-chloropropoxy)-3-methoxyphenyl) ethanone (4) with 6- fluoro-3-piperidin-4-yl-1, 2-benzisoxazole hydrochloride (5) in a mixture of water and heptane as solvent and sodium hydroxide as a base in the presence of ...