Butaperazine (Repoise, Tyrylen) is a typical antipsychotic of the phenothiazine class.[1] It was approved in 1967, and possibly discontinued in the 1980s.
2-Butyrylphenothiazine [25244-91-1] (1) is the requisite starting material for carrying out the procedure. It is prepared in a manner that is synonymous with the method used in the propiomazine and propiopromazine already discussed. The 1-(γ-chloropropyl)-4-methylpiperazine [104-16-5] (2) is prepared in the conventional way from alkylating 1-methylpiperazine and 1-Bromo-3-chloropropane. Sodamide is used to extract the 10-H thereby facilitating the nucleophilic substitution reaction. And completing the instalment of the sidechain.