Chlorproethazine

Chlorproethazine, sold under the brand name Neuriplege, is a drug of the phenothiazine group described as a muscle relaxant or tranquilizer which is or has been marketed in Europe as a topical cream for the treatment of muscle pain. It has been associated with photoallergic contact dermatitis.

Synthesis

Chlorproethazine can be synthesized from a diphenylsulfide derivative. The general scheme is sufficiently flexible to permit the interchange of the order of some of the steps.
Thus alkylation of 2--5-chloro-aniline with 3-chloro-1-diethylaminopropane leads to the intermediate. Ring closure as above by nucleophilic aromatic displacement leads to the antipsychotic drug chlorproethazine.
The last step uses copper powder and is a form of the Ullmann condensation.