7124-94-9Relevant academic research and scientific papers
Conformations and Conformational Processes of Hexahydrobenzazocines by NMR and DFT Studies
Musielak, Bogdan,Holak, Tad A.,Rys, Barbara
, p. 9231 - 9239 (2015/09/28)
Conformational processes that occur in hexahydrobenzazocines have been studied with the 1H and 13C dynamic nuclear magnetic resonance (DNMR) spectroscopy. The coalescence effects are assigned to two different conformational processes: the ring-inversion of the ground-state conformations and the interconversion between two different conformers. The barriers for these processes are in the range of 42-52 and 42-43 kJ mol-1, respectively. Molecular modeling on the density functional theory (DFT) level and the gauge invariant atomic orbitals (GIAO)-DFT calculations of isotropic shieldings and coupling constants for the set of low-energy conformations were compared with the experimental NMR data. The ground-state of all compounds in solution is the boat-chair (BC) conformation. The BC form adopts two different conformations because the nitrogen atom can be in the boat or chair parts of the BC structure. These two conformers are engaged in the interconversion process.
Effect of ring size or an additional heteroatom on the potency and selectivity of bicyclic benzylamine-type inhibitors of phenylethanolamine N- methyltransferase
Grunewald, Gary L.,Dahanukar, Vilas H.,Ching, Piao,Criscione, Kevin R.
, p. 3539 - 3546 (2007/10/03)
In the search for potent and selective inhibitors of the enzyme phenylethanolamine N-methyltransferase (PNMT; EC 2.1.1.28), we examined the effect of ring size or an additional heteroatom in the conformationally- restricted benzylamine-type PNMT inhibitors. Based on semiempirical calculations (MNDO) and molecular modeling studies, PNMT-inhibitory activity of these compounds seemed to be dependent on (a) the torsion angle between the plane of the aromatic ring and the endo N atom lone pair (τ2 angle), with the optimal value of τ2 being about -75°, and (b) the amount of steric bulk about the 3-position of 1,2,3,4-tetrahydroisoquinoline (5, THIQ). 2,3,4,5-Tetrahydro-1H-2-benzazepine (6) was found to have the highest selectivity (PNMT K(i) = 3.34 μM, α2 K(i) = 11 μM, selectivity = 3.2) as compared to other homologues of THIQ (PNMT K(i) = 9.67 μM, α2 K(i) = 0.35 μM, selectivity = 0.036). The higher PNMT-inhibitory activity of 6 was attributed to favorable steric interactions of the puckered methylene groups in the putative bioactive conformation of 6 at the PNMT active site, whereas unfavorable interactions of these puckered methylene groups at the α2- adrenoceptor were thought to be the cause of reduced α2 affinity of 6. No further enhancement of the selectivity of the benzazepine ring system could be obtained via introduction of a second heteroatom (N, O, S) at the 5- position in this ring system.
Synthesis of Fused Heterocycles: 1,2,3,4-Tetrahydroisoquinolines and Ring Homologues via Sulphonamidomethylation
Orazi, Orfeo O.,Corral, Renee A.,Giaccio, Hector
, p. 1977 - 1982 (2007/10/02)
The title heterocycles (3) have been obtained by a two-step synthesis; namely an initial intramolecular sulphonamidomethylation of N-aralkylsulphonamides (1) in acid media followed by desulphonylation of compounds (2) under moderate conditions, either by reduction or acid hydrolysis.Generally both steps gave good or high yields of compounds (3) variously substituted in the aromatic ring and with a six-, seven-, or eight-membered heterocyclic ring.
