Synthesis of new 5-phenyl[1,2,4]triazole derivatives as ligands for the 5-HT1A serotonin receptor

A series of 4-amino-3-[[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]thio]-5-(substitutedphenyl)[1,2,4]triazoles (5a-f) and the isomeric 4-amino-2-[2-[4-(2-methoxyphenyl)-1-piperazinyl]ethyl]-5-(substitutedphenyl)-2,4-dihydro-3H[1,2,4]triazole-3-thiones (6a-f) and aseries of 3-[[2-[4-(2-methoxy or 2-nitrophenyl)1-piperazinyl]ethyl]thio]-5-(substitutedphenyl)[1,2,4]triazoles (8a-i) were synthesized with the aim of obtaining new selective 5-HT1Aligands, with reduced affinity for the α1-adrenoceptor subtypes. New compounds were tested inradioligand binding experiments where many of them showed a preferential affinity for the 5-HT1A receptor.