Carfenazine (INN; former development code WY-2445; BAN carphenazine; USAN carphenazine maleate; brand name Proketazine; former development code NSC-71755) is an antipsychotic and tranquilizer of the phenothiazine group that was withdrawn from the market.
The alkylation reaction between 2-propionyl phenothiazine (1) and 1-bromo-3-chloropropane (2) gives 1-[10-(3-chloropropyl)phenothiazin-2-yl]propan-1-one (3). A second alkylation step, this time with 2-(1-Piperazinyl)ethanol (4), completes the synthesis of carfenazine (5).
Although above procedure is proof-of-concept, bear in mind no protecting group. Other patent uses ketalization technique.