Pirlindole


Pirlindole, sold under the brand names Lifril and Pyrazidol, is mainly a reversible inhibitor of monoamine oxidase A and secondly a serotonin–norepinephrine reuptake inhibitor which was developed and is used in Russia as an antidepressant. It is structurally and pharmacologically related to metralindole.

Synthesis

The Fischer indole synthesis between p-Tolylhydrazine Hydrochloride and 1,2-Cyclohexanedione gives 6-methyl-2,3,4,9-tetrahydrocarbazol-1-one . Imine formation with ethanolamine gives . Halogenation with phosphorus oxychloride gives. Intramolcular alkylation with the indole nitrogen resulted in Dehydropirlindole . Reduction of the imine with sodium borohydride completes the synthesis of pirlindole.