- Noncovalently Functionalized Commodity Polymers as Tailor-Made Additives for Stereoselective Crystallization
-
Stereoselective inhibition of the nucleation and crystal growth of one enantiomer aided by “tailor-made” polymeric additives is an efficient method to obtain enantiopure compounds. However, the conventional preparation of polymeric additives from chiral monomers are laborious and limited in structures, which impedes their rapid optimization and applicability. Herein, we report a “plug-and-play” strategy to facilitate synthesis by using commercially available achiral polymers as the platform to attach various chiral small molecules as the recognition side-chains through non-covalent interactions. A library of supramolecular polymers made up of two vinyl polymers and six small molecules were applied with seeds in the selective crystallization of seven racemates in different solvents. They showed good to excellent stereoselectivity in yielding crystals with high enantiomeric purities in conglomerates and racemic compound forming systems. This convenient, low-cost modular synthesis strategy of polymeric additives will allow for high-efficient, economical resolution of various racemates on different scales.
- Wan, Xinhua,Wang, Zhaoxu,Ye, Xichong,Zhang, Jie
-
p. 20243 - 20248
(2021/08/09)
-
- Compound and its as L-type calcium channel blocker or/and application of acetylcholine esterase inhibitors
-
Disclosed in this invention are compounds and the uses as L-type calcium channel blocker and/or acetylcholinesterase inhibitor thereof. The uses of said compounds in the manufactures of a medicament for the treatment of cardiovascular diseases, apoplexy or senile dementia are also disclosed in the present invention.
- -
-
-
- Syntheses, calcium channel antagonist and anticonvulsant activities of substituted 1,4-dihydro-3,5-pyridinedicarboxylates containing various 3-alkyl ester substituents
-
A group of 3-alkyl-5-isopropyl 4-aryl-1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylates 10-20 containing an amine, quaternary ammonium, aryl(heteroaryl)alkenyl, 4-(4-fluorophenyl)-piperazin-1-yl or methoxy moiety in the C-3 alkyl ester R-substituent in combination with a C-4 phenyl ring bearing a 2,3-Cl2, 3-NO2, 3-NMe2, 4-NMe2 or 3,4,5-(OMe)3 X-substituent were prepared using the Hantzsch 1,4-dihydropyridine reaction. In vitro calcium channel antagonist activity (CCA) was determined using a guinea pig ileum longitudinal smooth muscle assay. In the C-4 3-nitrophenyl series of compounds, the C-3 ester R substituent was a determinant CCA activity where the relative potency order was -CH2CH2CH=C-(2-methylphenyl)2 ≤ -CH2CH2NMe2.HCl > -CH2CH2CH=C (3-methyl-2-thienyl)2 > -CH2CH2+NMe3I-. The position and nature of the C-4 phenyl X-substituent, were also determinants of CCA activity where the relative activity order was 3-NMe2>4-NMe2>3,4,5-(OMe)3. Anticonvulsant activities were determined in mice using the subcutaneous metrazol (scMet) and maximal electroshock (MES) screens. The compounds investigated were generally not effective for protecting against scMet induced seizures, except for 10 {X = 2,3-Cl2, R = 2-[4-(4-fluorophenyl)piperazin-1-yl]ethyl} and 14a (X = 3-NMe2.HCl, R = CH2CH2OMe), which exhibited modest activity. Compound 11a (X = 3-NO2, R = -CH2CH2NMe2.HCl) was the most effective agent in the MES screen. All of the compounds investigated, except for 11b (X = 3-NO2, R = -CH2CH2+NMe3 I-, Kp = 0.15) are lipophilic with n-octanol/aqueous phosphate buffer (pH = 7.4) partition coefficients (Kp) in the 121-424 range relative to the reference drug nimodipine (Kp = 187). The structure-activity relationship acquired reinforce the concept that calcium is only one of several factors that are involved in seizure generation.
- Yiu, Sai-Hay,Knaus, Edward E.
-
-
- Mild and facile cleavage of 2-cyanoethyl ester using sodium sulfide or tetrabutylammonium fluoride. Synthesis of 1,4-dihydropyridine monocarboxylic acids and unsymmetrical 1,4-dihydropyridine dicarboxylates
-
Several 3-(2-cyanoethyl)-1,4-dihydropyridine carboxylates (16) were prepared in moderate to good yields by means of the Hantzsch reaction. Treatment of these carboxylates with a weak base such as sodium sulfide or tetrabutylammonium fluoride at room temperature afforded smoothly the corresponding 1,4-dihydropyridine monocarboxylic acids (18) in good yields. The monocarboxylic acids 18n and 18o were esterified with 2-nitrooxypropanol or N-(2-hydroxyethyl)nicotinamide p-toluenesulfonic acid salt to afford the selective coronary vasodilators CD-349 (5) and CD-832 (6), respectively.
- Ogawa,Hatayama,Maeda,Kita
-
p. 1579 - 1589
(2007/10/02)
-
- Synthesis and antihypertensive activities of new 1,4-dihydropyridine derivatives containing a nitrooxy moiety at the 3-ester position
-
The synthesis of a new series of dihydropyridines containing a nitrooxy moiety at the 3-ester position is described. The antihypertensive activity of the compounds was examined and compared with that of nifedipine; some of them were relatively potent. The structure-activity relationship is also discussed.
- Ogawa,Nakato,Tsuchida,Hatayama
-
p. 108 - 116
(2007/10/02)
-
- Process for preparation of enantiomerically pure polysubstituted 1,4-dihydropyridines
-
A process for the optical resolution of racemic 1,4-dihydropyridines, containing isothioureido groups. Salification of racemic isothioureas with optically active acids produces diasteroisomeric mixtures of isothiouronium salts, that, using conventional techniques, are separated in the individual components to give optically pure isothioureides of 1,4-dihydropyridines and salts thereof with conventional acids. Said optically pure 1,4-dihydropyridines can then be subjected to desulphuration and to different transformations to give to other enantiomerically pure and therapeutically useful 1,4-dihydropyridines.
- -
-
-
- Resolution of 1,4-dihydropyridine derivatives
-
Optically active compounds of formula 1 STR1 wherein R1 is H or lower alkyl; R2 and R6 are each independently lower alkyl, aryl, or arylalkyl; R3 is CN, NO2, CO2 R5, CONHR5, SO2 R5, or P(O)(OR5)2, where R5 is lower alkyl, lower alkoxyalkyl, aryl, or arylalkyl; R4 is aryl, heterocyclyl, or fused-ring heterocyclyl, optionally substituted with one, two, or three halo, NO2, CN, lower alkyl, lower alkoxy, lower alkylamino, CF3, OCH2 F, or OCF3 ; are prepared by fractional crystallization from hot organic solvent and water in the presence of a suitable optically active amine base.
- -
-
-
- Antihypertensive 1,4-dihydropyridines having a conjugated ester
-
1,4-dihydropyridine derivatives represented by the following general formula, STR1 in which R3 is a combination of an unsaturated straight chain hydrocarbon group or derivative thereof connected by a single bond with an unsaturated hydrocarbon group or derivative thereof so that the unsaturated carbon atoms of the two groups are in conjugated relationship. These compounds have a hypotensive action the effective time of which is long, which makes the blood pressure descend slowly, and the toxicity of which is low.
- -
-
-
- Nimodipine: Synthesis and metabolic pathway
-
Key step of the synthesis of the calcium antagonistic cerebral vasodilator (±) isopropyl-2-methoxyethyl 1,4-dihydro-2,6-dimethyl-4-(3-nitrophenyl)-3,5-pyridinedicarboxylate (Bay e 9736, nimodipine) is the cyclising Michael addition. A pharmacokinetic study with 14C-nimodipine in the rat revealed as major metabolites the dihydropyridines as well as the pyridines. A potential metabolic pathway is discussed involving ether cleavage and oxidation to the pyridine form as primary biotransformation steps. Reference metabolites were synthesized using 1,4-dihydropyridines with appropriate functionalities as precursors.
- Meyer,Wehinger,Bossert,Scherling
-
p. 106 - 112
(2007/10/02)
-
- 1,4-Dihydropyridinecarboxylic acids
-
The invention relates to a process for the production of 1,4-dihydropyridinecarboxylic acid compounds which involves hydrolysis, under alkaline conditions and in a temperature range from 10° to 100° C., of an ester group which contains an electron-attract
- -
-
-
- 1,4-Dihydropyridines
-
1,4-Dihydropyridines characterized by a carbo(arylalkoxy) group in the 5-position, an aryl group in the 4-position and a alkanoyl or carbalkoxy group in the 3-position and further optionally substituted in the 1,2 and 6-positions are coronary dilating, sp
- -
-
-