238427-82-2Relevant articles and documents
Synthesis and serotonergic activity of substituted 2,N- benzylcarboxamido-5-(2-ethyl-1-dioxoimidazolidinyl)-N,N-dimethyltryptamine derivatives: Novel antagonists for the vascular 5-HT(1B)-like receptor
Moloney, Gerard P.,Martin, Graeme R.,Mathews, Neil,Milne, Aynsley,Hobbs, Heather,Dodsworth, Susan,Sang, Pang Yih,Knight, Cameron,Williams, Marnie,Maxwell, Miles,Glen, Robert C.
, p. 2504 - 2526 (2007/10/03)
The synthesis and vascular 5-HT(1B)-like receptor activity of a novel series of substituted 2,N-benzylcarboxamido-5-(2-ethyl-1- dioxoimidazolidinyl)-N,N-dimethyltryptamine derivatives are described. Modifications to the 5-ethylene-linked heterocycle and to substituents on the 2-benzylamide side chain have been explored. Several compounds were identified which exhibited affinity at the vascular 5-HT(1B)-like receptor of pK(B) > 7.0, up to 100-fold selectivity over α1-adrenoceptor affinity and 5-HT(2A) receptor affinity, and which exhibited a favorable pharmacokinetic profile. N-Benzyl-3-[2-(dimethylamino)ethyl]-5-[2-(4,4-dimethyl-2,5-dioxo-1- imidazolidinyl)ethyl]-1H-indole-2-carboxamide (23) was identified as a highly potent, silent (as judged by the inability of angiotensin II to unmask 5- HT(1B)-like receptor-mediated agonist activity in the rabbit femoral artery), and competitive vascular 5-HT(1B)-like receptor antagonist with a plasma elimination half-life of ~4 h in dog plasma and with good oral bioavailability. The selectivity of compounds from this series for the vascular 5-HT(1B)-like receptors over other receptor subtypes is discussed as well as a proposed mode of binding to the receptor pharmacophore. It has been proposed that the aromatic ring of the 2,N-benzylcarboxamide group can occupy an aromatic binding site rather than the indole ring. The resulting conformation allows an amine-binding site to be occupied by the ethylamine nitrogen and a hydrogen-bonding site to be occupied by one of the hydantoin carbonyls. The electronic nature of the 2,N-benzylcarboxamide aromatic group as well as the size of substituents on this aromatic group is crucial for producing potent and selective antagonists. The structural requirement on the 3-ethylamine side chain incorporating the protonatable nitrogen is achieved by the bulky 2,N-benzylcarboxamide group and its close proximity to the 3- side chain.
