6712-12-5Relevant articles and documents
Novel Potassium-Channel Openers: Preparation and Pharmacological Evaluation of Racemic and Optically Active N-(6-Amino-3-pyridyl)-N'-bicycloalkyl-N"-cyanoguanidine Derivatives
Eda, Masahiro,Takemoto, Tadahiro,Ono, Shin-ichiro,Okada, Takehiro,Kosaka, Keigo,et al.
, p. 1983 - 1990 (2007/10/02)
The previous paper reported on the synthesis and pharmacological evaluation of N-(6-amino-3-pyridyl)-N'-bicycloalkyl-N"-cyanoguanidine derivatives, from among which three compounds were selected as potent potassium-channel openers. In the present study, selected compounds were tested for antagonism of potassium-induced contraction of rat aorta, hypotensive activity in normotensive rats, and diuretic activity in spontaneously hypertensive rats. This led to further evaluation of compound (+/-)-10 and selection of (+)-N-(6-amino-3-pyridyl)-N'-hept-2-yl>-N"-cyanoguanidine ((+)-10) (AL0670) for development as an antihypertensive agent. Although AL0670 is regarded as a pinacidil-type K+-channel opener, it showed different pharmacological and conformational profiles from pinacidil.
Enzymatic Preparation of Optically Active Bicycloheptene Derivatives, Building Blocks of Terpenoid Natural Products. An Attractive Alternative to Enantioselective Diels-Alder Syntheses
Eycken, J. Van der,Vandewalle, M.,Heinemann, G.,Laumen, K.,Schneider M. P.,et al.
, p. 306 - 308 (2007/10/02)
Bicycloheptene derivatives (1)-(3), building blocks of terpenoid natural products, have been prepared with high enantiometric purities by enzymatic hydrolysis of their racemic esters in the presence of porcine liver esterase (PLE) and an ester hydrolase from Pseudomonas sp. (SAM-II).
Carbon Participation in the Solvolysis of 6-exo-substituted 2-exo- and 2-endo-Norbornyl p-Toluenesulfonates. Norbornanes Part 5
Fischer, Walter,Grob, Cyril A.,Hanreich, Reinhard,Sprecher, Georg von,Waldner, Adrian
, p. 2298 - 2311 (2007/10/02)
The solvolysis rates and products of the 6-exo-substituted 2-exo- 1a-1u, and 2-endo-norbornyl p-toluenesulfonates 2a-2u, have been determined.In general, the rate constants for 1 and 2 (log k) correlate well with the inductive constants ?qI of the substituents at C(6); however, their sensitivity to ?qI is much larger in the 2-exo-series 1 than in the 2-endo-series 2.This differential transmission of polar effects is the cause of decreasing 2-exo/2-endo rate ratios from 2388 for R=t-C4H9 to 0.37 for R=Br, i.e., with increasing electron attraction by the substituent.The high sensitivity of the rate constants for the 2-exo-p-toluenesulfonates 1 to ?qI indicates an unusually strong inductive interaction between C(6) and the incipient cationic center at C(2).This interaction is ascribed to the participation of the pentacoordinate C(6)-atom, i.e. to 1,3-bridging, a consequence of steric hindrance of nucleophilic solvent participation in norbornanes.Donor substituents enhanche 1,3-bridging, lead to faster reactions and to the formation of 2-exo substitution products.Conversely, acceptor substituents reduce 1,3-bridging, decrease rates and facilitate the formation of 2-endo substitution products.Graded 1,3-bridging is discussed in the light of Winstein's nonclassical ion concept.