Pirandamine (AY-23,713) is a tricyclic derivative which acts as a selective serotonin reuptake inhibitor (SSRI).[1] [2] [3] It was investigated in the 1970s as a potential antidepressant but clinical development was not commenced and it was never marketed. Pirandamine is structurally related to tandamine, which, in contrast, is a selective norepinephrine reuptake inhibitor.
Pirandamine can be synthesized starting from 1-indanone.[4] The Reformatsky reaction between 1-indanone (1) and ethyl bromoacetate in the presence of zinc gives ethyl 2-(1-hydroxy-2,3-dihydroinden-1-yl)acetate (2). The reduction of the ester with ester with lithium aluminum hydride (LiAlH4) gives 1-(2-hydroxyethyl)-2,3-dihydroinden-1-ol (3). Acid-catalyzed dehydration then leads to indene-3-ethanol (4). Acid-catalyzed condensation with ethyl acetoacetate then gives (5). The saponification of the ester then gives the corresponding acid. The reaction of this with ethyl chloroformate gives a mixed anhydride, and further reaction of this with dimethylamine then leads to the amide (6). Reduction with lithium aluminium hydride completes the synthesis of pirandamine (7).