Benzocycloheptapyridinone (I) was reduced to alcohol (II) with NaBH4 in MeOH. Subsequent treatment of (II) with SOCl2 in toluene gave the tricyclic chloride (III). Finally, alkylation of N-acetyl piperazine (IV) with chloride (III) in the presence of Et3N in boiling THF provided the title compound.