Synthesis and structure–activity relationships of a new model of arylpiperazines. Part 7: Study of the influence of lipophilic factors at the terminal amide fragment on 5-HT1A affinity/selectivity
摘要:
The influence of lipophilic factors at the amide fragment of a new series of (+/-)-7a-alkyl-2-[4-(4-arylpiperazin-1-yl)butyl]1,3-dioxoperhydropyrrolo[1,2-c]imidazoles 2 and of (+/-)-7a-alkyl-2-[(4-arylpiperazin-1-yl)methyl]-1,3-dioxoperhydropyrrolo[1,2-c]imidazoles 3 has been studied. Variations of logP have been carried out by introducing different hydrocarbonated substituents (R-1) at the position 7a of the bicyclohydantoin, namely the non-pharmacophoric part. All the new compounds exhibit high potency for the 5-HT1A receptor; however, affinities for the a, receptor are high for compounds 2a-l while compounds 3a-f are selective over this adrenergic receptor. On the other hand, differences in logP do not notably affect the K-i values for the above receptors. (C) 2003 Elsevier Ltd. All rights reserved.
Synthesis and Structure−Activity Relationships of a New Model of Arylpiperazines. 1. 2-[[4-(o-Methoxyphenyl)piperazin-1-yl]methyl]-1,3- dioxoperhydroimidazo[1,5-a]pyridine: A Selective 5-HT1A Receptor Agonist
摘要:
A series of new bicyclohydantoin-arylpiperazines was prepared and evaluated for affinity at 5-HT1A, alpha(1), and D-2 receptors. Most of the compounds showed very low affinity for D-2 receptors, and most of them demonstrated moderate to high affinity for 5-HT1A and alpha(1) receptor binding sites. SAR observations indicated that the length of the alkyl chain between the arylpiperazine and the hydantoin moiety is of great importance for 5-HT1A/alpha(1) affinity and selectivity, n = 1 being the optimal value. Compound 1h, 2-[[4-(o-methoxyphenyl)piperazin-1-yl]methyl]-1,3-dioxoperhydroimidazo[1,5-a]pyridine, bound at 5-HT1A sites with nanomolar affinity (K-i = 31.7 nM) and high selectivity over alpha(1), D-2, and 5-HT2A receptors (K-i > 1000, > 10 000, and > 1000 nM, respectively). Preliminary studies showed that this agent is probably functioning as a partial to full 5-HT1A agonist, and it displayed anxiolytic activity on the social interaction test in mice.