نتایج جستجو برای: dihydropyridines

تعداد نتایج: 1708  

Journal: :Processes 2023

The multicomponent reaction of 2-nitroacetophenone (or nitroacetone), acetaldehyde diethyl acetal, ?-dicarbonyl compound, and ammonium acetate in an acetic acid solution allowed the acquisition previously undescribed 4-methyl-substituted derivatives 5-nitro-1,4-dihydropyridine satisfactory yields. oxidation obtained resulted corresponding 2,4-dimethyl-5-nitropyridines. In addition, for first ti...

Journal: :Free radical research 2004
V Valenzuela P Santander C Camargo J A Squella C López-Alarcón L J Núñez-Vergara

In the present paper, a direct quenching of radical species by a number of synthesized nitrosoaryl 1,4-dihydropyridines and their parent nitroaryl 1,4-dihydropyridines was determined in aqueous media at pH 7.4. These two series of compounds were compared with the C-4 unsubstituted 1,4-dihydropyridines derivatives and the corresponding C-4 aryl substituted 1,4-dihydropyridines derivatives. Kinet...

Journal: :Organic & biomolecular chemistry 2009
Huanfeng Jiang Ronghuan Mai Hua Cao Qiuhua Zhu Xiaohang Liu

Highly functionalized multisubstituted 1,4-dihydropyridines 5 have been concisely synthesized in moderate to good yields via L-proline-catalyzed one-pot multicomponent reactions (MCRs) of alkynoates or alkynones 1, amines 2, beta-dicarbonyl compounds 3 and aldehydes 4 under mild conditions. The MCR process involves hydroamination/Knoevenagel condensation/Michael-type addition/intramolecular cyc...

Journal: :Chemical communications 2015
Sridhar Undeela Srinivas Thadkapally Jagadeesh Babu Nanubolu Kiran Kumar Singarapu Rajeev S Menon

Gold-catalysed, divergent synthesis of 2-sulfonylmethyl pyrroles and dihydropyridines from N-propargyl-N-vinyl sulfonamides has been achieved. Echavarren's gold(I) catalyst promoted the formation of pyrrole derivatives whereas the combination of PPh3AuCl and AgSbF6 afforded dihydropyridines. The aza-enyne precursors for the cycloisomerisation reaction were prepared by a base-mediated formal vin...

Journal: :The Analyst 2011
Yunfeng Chai Hezhi Sun Jieping Wan Yuanjiang Pan Cuirong Sun

During the positive-ion mode electrospray ionization mass spectrometry analysis of 1,4-diphenyl-3-benzoyl-1,4-dihydropyridines with methanol as the solvent, the major ion generated is one mass unit lower than the analyte, which can be rationalized as the oxidative aromatization of 1,4-dihydropyridines to pyridine cations.

Journal: :Organic & biomolecular chemistry 2015
Haruki Mizoguchi Ryo Watanabe Shintaro Minami Hideaki Oikawa Hiroki Oguri

Copper-catalyzed 6-endo cyclization of N-propargylic β-enaminocarbonyls was developed for the synthesis of oxidation-labile 1,6-dihydropyridines. This synthetic method allows flexible and regio-defined assembly of various substituents at the N1, C2, C3, C4, and C6 positions of 1,6-dihydropyridines under mild conditions.

Journal: :Neuron 2007
David Sulzer Yvonne Schmitz

Pacemaking activity in adult substantia nigra (SN) dopamine neurons relies on L-type Ca2+ channels, but a surprising study in Nature by Chan et al. demonstrates that blockade of these channels by dihydropyridines re-establishes the pacemaking driven by sodium and HCN channels found in juvenile SN. This shift protects SN neurons in chemical models of Parkinson's disease (PD), suggesting that ele...

2012
Nouria A Al-Awadi Maher R Ibrahim Mohamed H Elnagdi Elizabeth John Yehia A Ibrahim

An efficient three component reaction with enaminones, primary amines and aldehydes resulted in easy access to 1,4-dihydropyridines with different substituents at the 1-, 3-, 4- and 5-positions. Microwaves improved the reaction yield, reducing also considerably the reaction time and the amount of solvent used. Chiral primary amines gave chiral 1-substituted-1,4-dihydropyridines. The 4-(1-naphth...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1984
S B Freedman R J Miller

Depolarization of NG108-15 (neuroblastoma-glioma) cells causes an increase in 45Ca2+ influx. This effect is blocked by low concentrations of dihydropyridines such as nitrendipine and by other blockers of voltage-sensitive calcium channels such as D-600, diltiazem, and Cd2+. Two other dihydropyridines, BAY K8644 and CGP 28392, have the opposite effect. Low concentrations of these compounds enhan...

Journal: :Annual review of pharmacology and toxicology 1997
G H Hockerman B Z Peterson B D Johnson W A Catterall

The crucial role of L-type Ca2+ channels in the initiation of cardiac and smooth muscle contraction has made them major therapeutic targets for the treatment of cardiovascular disease. L-type channels share a common pharmacological profile, including high-affinity voltage- and frequency-dependent block by the phenylalkylamines, the benz(othi)azepines, and the dihydropyridines. These drugs are t...

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