Melperone

Melperone (Bunil (PT), Buronil (AT, BE, CZ, DK, FI^†, NL^†, NO^†, SE), Eunerpan (DE)) is an atypical antipsychotic of the butyrophenone chemical class, making it structurally related to the typical antipsychotic haloperidol. It first entered clinical use in 1960s.

It has been tried in treatment-resistant cases of schizophrenia with some (albeit limited) success. It has also been reported effective in the treatment of L-DOPA and other forms of psychosis in Parkinson's disease (although a multicentre, double-blind, placebo-controlled study conducted in 2012 failed to support these findings). It is also known to possess anxiolytic properties. It is marketed in the following countries:

Melperone is reported to produce significantly less weight gain than clozapine and approximately as much weight gain as typical antipsychotics. It is also purported to produce around as much prolactin secretion as clozapine (which is virtually nil). It is also purported to produce sedative effects and QT interval prolongation. It is also known to produce less extrapyramidal side effects than the first-generation (typical) antipsychotic, thiothixene. It can also produce (usually relatively mild) dry mouth.

Melperone is reported to be a CYP2D6 inhibitor.

Melperone binds to the dopamine D₂ receptor, just like all other clinically utilized antipsychotics, but it does so with a very low affinity and hence may be liable to rapidly dissociate from the D₂ receptor hence potentially giving it the profile of an atypical antipsychotic.

For the last step of the synthesis the sidechain 4-Chloro-4'-Fluorobutyrophenone [3874-54-2] (1) is attached to 4-Methylpiperidine (4-Pipecoline) [626-58-4] (2).