21000-80-6Relevant articles and documents
Synthesis, NMR conformational analysis and pharmacological evaluation of 7,7a,13,14-tetrahydro-6H-cyclobuta[b]pyrimido[1,2-a:3,4-a′]diindole analogues as melatonin receptor ligands
Attia, Mohamed I.,Gueclue, Deniz,Hertlein, Barbara,Julius, Justin,Witt-Enderby, Paula A.,Zlotos, Darius P.
, p. 2129 - 2137 (2007)
A structure for the self-condensation product of 2-(1H-indol-2-yl)ethyl tosylate 2a, previously proposed as 6,7,14,15-tetrahydro-15aH-azocino[1,2-a:6,5- b]diindole 3a, was revised based on the 13C-2D-INADEQUATE experiment, and proved to be 7,7a,13,14-tetrahydro-6H-cyclobuta[b]pyrimido[1,2-a:3,4- a′]diindole 4a. A mechanism for the unexpected formation of this novel hexacyclic heterocycle was proposed and its NMR solution structure was elucidated. Five derivatives of the title ring skeleton 12-16 designed as melatonin receptor ligands were synthesized and their affinities for the human MT1 and MT2 receptors were determined. Both butyramides 13 and 15, as well as the non-methoxy acetamide 12 exhibited micromolar binding affinities for both receptors being slightly MT2 selective. The methoxy acetamide 14 showed the best pharmacological profile exhibiting a five times higher affinity for MT1 (Ki = 49 nM) than for MT2 (Ki = 246 nM) receptor. This journal is The Royal Society of Chemistry.