Effect of Acyl Chain Length and Branching on the Enantioselectivity of Candida rugosa Lipase in the Kinetic Resolution of 4-(2-Difluoromethoxyphenyl)-Substituted 1,4-Dihydropyridine 3,5-Diesters
摘要:
Since 2,6-dimethyl-4-aryl-1,4-dihydropyridine 3,5-diesters themselves are not hydrolyzed by commercially available hydrolases, derivatives with spacers containing a hydrolyzable group were prepared. Seven acyloxymethyl esters of 5-methyl- and 5-(2-propoxyethyl) 4-[2-(difluoromethoxy)phenyl]-2,6-dimethyl-1,4-dihydro-3,5-pyridinedicarboxylate were synthesized and subjected to Candida rugosa lipase (CRL) catalyzed hydrolysis in wet diisopropyl ether. A methyl ester at the 5-position and a long or branched acyl chain at C3 gave the highest enantiomeric ratio (E values). The most stereoselective reaction (E = 21) was obtained with 3-[(isobutyryloxy)methyl] 5-methyl 4-(2-difluoromethoxyphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate, and this compound was used to prepare both enantiomers of 3-methyl 5-(2-propoxyethyl) 4-[2-(difluoromethoxy)phenyl]2,6-dimethyl-1,4-dihydro-3,5-pyridinedicarboxylate. The absolute configuration of the enzymatically produced carboxylic acid was established to be 4R by X-ray crystallographic analysis of its 1-(R)-phenylethyl amide.
1,4-Dihydropyridines as antagonists of platelet activating factor. 1. Synthesis and structure-activity relationships of 2-(4-heterocyclyl)phenyl derivatives
作者:Kelvin Cooper、M. Jonathan Fray、M. John Parry、Kenneth Richardson、John Steele
DOI:10.1021/jm00095a005
日期:1992.8
A novel class of 2-(4-heterocyclylphenyl)-1,4-dihydropyridines (2-38) possessing antagonist activity against platelet activating factor (PAF) was prepared by the Hantzsch synthesis from a variety of ethyl 4'-heterocyclic-substituted benzoylacetates, aryl or heteroaryl aldehydes, and substituted 3-aminocrotonamides or 3-aminocrotonate esters. Structure-activityrelationships were evaluated where PAF
Design and Synthesis of Novel α<sub>1a</sub> Adrenoceptor-Selective Dihydropyridine Antagonists for the Treatment of Benign Prostatic Hyperplasia
作者:Dhanapalan Nagarathnam、John M. Wetzel、Shou Wu Miao、Mohammad R. Marzabadi、George Chiu、Wai C. Wong、Xingfang Hong、James Fang、Carlos Forray、Theresa A. Branchek、William E. Heydorn、Raymond S. L. Chang、Theodore Broten、Terry W. Schorn、Charles Gluchowski
DOI:10.1021/jm980506g
日期:1998.12.1
We report the synthesis and evaluation of novel alpha(1a) adrenoceptor subtype-selective antagonists. Systematic modification of the lipophilic 4,4-diphenylpiperidinyl moiety of the dihydropyridine derivatives 1 and 2 provided several highly selective and potent alpha(1a), antagonists. From this series, we identified the 4-(methoxycarbonyl)-4-phenylpiperidine analogue SNAP 5540 (-) [(-)-63] for further characterization. When examined in an isolated human prostate tissue assay, this compound was found to have a K-i of 2.8 nM, in agreement with the cloned human receptor binding data (K-i = 2.42 nM). Further evaluation of the compound in isolated dog prostate tissue showed a K-i of 3.6 nM and confirmed it to be a potent antagonist (K-b = 1.6 nM). In vivo, this compound effectively blocked the phenylephrine-stimulated increase in intraurethral pressure (IUP) in mongrel dogs, at doses which did not significantly affect the arterial pressure (diastolic blood pressure, DBP), with a DBP K-b/IUP K-b ratio of 16. In addition, (-)-63 also showed greater than 40 000-fold selectivity over the rat L-type calcium channel and 200-fold selectivity over several G protein-coupled receptors, including histamine and serotonin subtypes. These findings prove that alpha(1a) adrenoceptor-subtype selective antagonists such as (-)-63 may be developed as uroselective agents for an improved treatment of BPH over nonselective alpha(1) antagonists such as prazosin and terazosin, with fewer side effects.