59875-58-0Relevant articles and documents
Intramolecular electron transfer in the photochemistry of some nitrophenyldihydropyridines
Fasani, Elisa,Fagnoni, Maurizio,Dondi, Daniele,Albini, Angelo
, p. 2037 - 2045 (2007/10/03)
4-Phenyl-1,4-dihydropyridine-3,5-dicarboxylates contain two π chromophores separated by an sp3 carbon. The lowest singlet is localized on the dihydropyridine moiety (1PyH2-Ph) and emits a blue fluorescence (with close to unitary efficiency in glass at 77 K). In 3-nitrophenyl derivatives (PyH2-PhNO2, some of which are photolabile drugs) the fluorescence is completely quenched. Reasonably, this is due to intramolecular electron transfer between the close-lying donor and acceptor moieties to give the charge-separated species (PyH2 .+-PhNO2.-). In EPA glass at 77 K, back-electron transfer gives the dihydropyridine-localized triplet ( 3PyH2-PhNO2), which emits a yellow phosphorescence. In solution, deprotonation from the radical cation on the dihydropyridine moiety initiates rearomatization, finally giving Py-PhNO 2 with low quantum yield (5 × 10-4 to 5 × 10-3, increasing up to 0.013 by irradiation at 254 nm, where direct excitation of the nitrophenyl chromophore contributes). In the presence of triethylamine, the reaction changes to neat reduction of the nitro group. When a tethered alkylamino group is present, oxidative degradation of that moiety occurs, again via an electron-transfer intramolecular process. This has been found with the drug nicardipine, where photodegration is more efficient (Φ 0.02 to 0.1). Donor-acceptor dyads of this type, easily available through the Hantzsch synthesis, may be useful for building new photoinduced electron-transfer systems.
Pyridyl compounds and pharmaceutical compositions containing them
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, (2008/06/13)
The present invention is concerned with new pyridine double esters of formula (I), their acids, and pharmaceutically acceptable salts. These compounds can be obtained by oxydation of the corresponding 1,4-dihydropyridines, and they are useful as cardioprotective agents in pharmaceutical compositions.
Synthesis of the metabolites of 2-(N-benzyl-N-methylamino)ethyl methyl 2,6-dimethyl-4-(m-nitrophenyl)-1,4-dihydropyridine-3,5-dicarboxylate hydrochloride (nicardipine hydrochloride, YC-93)
Shibanuma,Iwanami,Fujimoto,et al.
, p. 2609 - 2613 (2007/10/02)
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