5755-07-7Relevant academic research and scientific papers
Synthesis of Medium Ring Nitrogen Heterocycles via a Tandem Copper-Catalyzed C-N Bond Formation-Ring-Expansion Process
Klapars, Artis,Parris, Sean,Anderson, Kevin W.,Buchwald, Stephen L.
, p. 3529 - 3533 (2007/10/03)
A simple method for the preparation of medium ring heterocycles (7-, 8-, 9-, and 10-membered) has been developed. The process employs a Cu-catalyzed coupling of a β-lactam with an aryl bromide or iodide followed by intramolecular attack of a pendant amino group. In some instances, the intermediate β-lactam is observable but can be converted to the aza-heterocycle by catalysis. Acetic acid was found to be superior to transition metal complexes as a catalyst for this ring-expansion 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.
