Bivalent indoles exhibiting serotonergic binding affinity

A series of bis-5-carboxamidoindoles were prepared and examined in a number of serotonin assays (5HT1A, 5HT1D, 5HT1E, and 5HT UT).1 They were found to exhibit good affinity for the 5HT1A and 5HT1D receptor subtypes and to inhibit the 5HT uptake sites. Optimal 5HT1D potency was achieved for bivalent analogs 5f and 5g, whose linkers spanned 7 and 8 alkyl units. Analogs with longer alkyl chain linkers (n= 10, 12), 5h and 5i, exhibited no selectivity for the 5HT1D receptor over the 5HT1A receptor.