- Compatibility of supported ionic liquid phase catalysts under ultrasonication
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Various supported ionic liquid phase (SILP) catalysts containing hexafluorophosphate anion have been prepared by covalent grafting of imidazolium ionic liquid in the matrix of cellulose, silica and Merrifield resin followed by anion metathesis reaction. T
- Jagadale, Megha,Kale, Dolly,Salunkhe, Rajashri,Rajmane, Mohan,Rashinkar, Gajanan
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- Synthesis and Biological Activities of Nicotinaldehyde Based 1,4-Dihydropyridinedicarboxylates
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Abstract: 1,4-Dihydropyridinecarboxylates were prepared by the reaction of nicotinaldehydes with aminocrotonoates in the presence of p-TsOH at room temperature. The prepared compounds were evaluated for their anti-microbial, free-radical scavenging and α-glucosidase inhibitory activities. Compounds diethyl 2,6-diphenyl-4-(pyridin-3-yl)-1,4-dihydropyridine-3,5-dicarboxylate and diethyl 4-(2-chloro-5-(4-fluorophenyl)pyridin-3-yl)-2,6-diphenyl-1,4-dihydropyridine-3,5-dicarboxylate were identified as potent anti-fungal agents. The compounds diethyl 2,6-dimethyl-4-(pyridin-3-yl)-1,4-dihydropyridine-3,5-dicarboxylate, dimethyl 4-(2-chloropyridin-3-yl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate and diethyl 2,6-dimethyl-4-(pyridin-4-yl)-1,4-dihydropyridine-3,5-dicarboxylate were identified as ABT?+ free radical scavengers. The compounds diethyl 4-(2-chloro-5-phenylpyridin-3-yl)-2,6-diphenyl-1,4-dihydropyridine-3,5-dicarboxylate and diethyl 4-(2-chloro-5-phenylpyridin-3-yl)-2,6-diphenyl-1,4-dihydropyridine-3,5-dicarboxylate denoted α-glucosidase inhibitory activity.
- Hariprasad, K. S.,Prakasham, R. S.,Praveena, G.,Raju, B. China,Ramya, S.,Suchitra Rani, K.,Tiwari, A. K.,Zehra, A.
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p. 1335 - 1340
(2021/12/23)
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- Simple Br?nsted acid catalyzed C-H functionalization: Efficient access to poly-substituted pyridines
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An exceptionally simple and environmentally friendly methodology has been developed for directly functionalizing the benzylic C-H bond of the poly-substituted pyridines with aromatic imines. Simple Br?nsted acid catalysts including salicylic acid and TsOH were successfully employed. Different types of poly-substituted pyridines could be efficiently obtained with moderate yields. Traditional ways to such types of pyridines involved the aromatization of the corresponding Hantzsch 1,4-dihydropyridines, while this method greatly simplified the synthetic procedures.
- Lai, Shujun,Ren, Xuwen,Zhao, Jinzhong,Tang, Zhuo,Li, Guangxun
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supporting information
p. 2957 - 2961
(2016/07/06)
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- Urease: A highly biocompatible catalyst for switchable Biginelli reaction and synthesis of 1,4-dihydropyridines from the in situ formed ammonia
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Urease is a superior biocompatible catalyst for switching from the Biginelli reaction to urea-based synthesis of 1,4-dihydropyridines in water, where 100% switching occurs at 0.02 g/mL of enzyme. Hantzsch reaction with ammonium acetate (NH4OAc) is inefficiently catalyzed by urease (70%, 4 h), and heavy metal ions inhibit the urease-catalyzed reactions with urea or NH4OAc. Promotion of the urea-based Hantzsch reaction by urease and its inhibition with Hg2 + supports specificity of urease for in situ generation of ammonia, whereas the role of urease in further transformations is not so specific. The features of this enzymatic method are reusability, mild reaction conditions, biocompatibility, generality, and high yield of products.
- Tamaddon, Fatemeh,Ghazi, Somayeh
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- Ultrasound-mediated, uranyl nitrate hexahydrate-catalyzed synthesis of 1,4-dihydropyridines under mild conditions
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Abstract Synthesis of 1,4-dihydropyridines by three-component condensation reaction of aldehyde, 1,3-dicarbonyl compounds, and ammonium acetate have been found to be efficiently catalyzed by uranyl nitrate hexahydrate [UO2(NO3)2 ·6H2O] at room temperature under ultrasound irradiation. This novel synthetic method offers the advantages of high yields, short reaction times, simplicity, and easy workup compared to the conventional methods reported in the literature.
- Palakshi Reddy,Sarveswari,Vijayakumar
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p. 6877 - 6883
(2015/08/18)
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- Ionic liquid [EMIM]OAc under ultrasonic irradiation towards synthesis of 1,4-DHP's
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The ionic liquid 1-ethyl-3-methylimidazole acetate ([EMIM]OAc) was found to be a mild and effective catalyst for the efficient, one-pot, three-component synthesis of 1,4-dihydropyridines from arylalde-hydes, ethylacetoacetate/ acetylacetone and ammonium acetate at room temperature under sonication. The developed method has many advantages, including devoid of harmful catalysts, reacting at room temperature, higher yields in a simple methodology or operational convenience.
- Palakshi Reddy,Rajesh,Vijayakumar
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experimental part
p. 384 - 388
(2011/10/31)
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- Etidronic acid catalyzed synthesis of 1,4-dihydropyridines
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One pot, three components cyclaconctensation reaction of various arylaldehydes. ethyl acetoacetate/acetyl acetone and ammonium acetate with etidronic acid as catalyst afforded the corresponding 1,4 -dihydropyridines in better yields under solvent free conditions.
- Reddey, B. Palakshi,Raiesh,Vijayakumar
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experimental part
p. 281 - 282
(2012/05/07)
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- Etidronic acid catalyzed synthesis of 1,4-dihydropyridines
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One pot, three components cyclocondensation reaction of various arylaldehydes, ethyl acetoacetate/acetyl acetone and ammonium acetate with etidronic acid as catalyst afforded the corresponding 1,4-dihydropyridines in better yields under solvent free conditions.
- Patakshi Reddy,Rajesh,Vijayakumar
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p. 281 - 282
(2013/09/24)
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- Synthesis of 3,4-dihydropyrimidin-2(1H)-ones and 1,4-dihydropyridines using ammonium carbonate in water
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Various known and new 3,4-dihydropyrimidin-2(1H)-ones and 1,4-dihydropyridines are prepared efficiently via Biginelli and Hantzsch reactions using ammonium carbonate in water. Competition between Biginelli and Hantzsch reactions is observed with pyridine carbaldehydes. Using this methodology, Hantzsch esters are synthesized in higher yields and purities than with other procedures without the use of a catalyst or an organic solvent.
- Tamaddon, Fatemeh,Razmi, Zahra,Jafari, Abbas Ali
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experimental part
p. 1187 - 1189
(2010/04/23)
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- Barium nitrate catalyzed one pot synthesis of 1,4-dihydropyridines under solvent free conditions at room temperature
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(Chemical Equation Presented) Barium nitrate acts as an efficient catalyst for the three-component one pot synthesis of 1,4-dihydropyridines. Barium nitrate is a safe chemical, and reaction without the use of organic solvents makes the process eco-friendly.
- Sharma, Mukul,Agarwal, Nisha,Rawat, Diwan S.
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p. 737 - 739
(2008/09/21)
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- Magnesium nitride as a convenient source of ammonia: preparation of dihydropyridines
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(Chemical Equation Presented) Magnesium nitride (Mg3N 2) has been investigated for the preparation of dihydropyridines. This is a commercially available, bench-stable solid that generates ammonia upon treatment with protic solvents. The main features of the process are the facile reaction setup and good yields obtained in the majority of cases.
- Bridgwood, Katy L.,Veitch, Gemma E.,Ley, Steven V.
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scheme or table
p. 3627 - 3629
(2009/05/07)
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- Synthesis of some new unsymmetrically substituted 1,4-dihydropyridines
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A series of some new 3,5-unsymmetrically substituted 1,4-dihydropyridines have been synthesized, which have ethoxycarbonyl and acetyl groups on 3- and 5-positions, respectively. A three-step procedure has been examined to increase the yield of the desired products, by suppressing the formation of the symmetrically substituted 3,5-diacetyl-1,4-dihydropyridines and 3,5-diethoxycarbonyl-1,4-dihydropyridines.
- Memarian, Hamid R.,Abdoli-Senejani, Masumeh,D?pp, Dietrich
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- Synthesis of 1,4-dihydropyridines under solvent-free conditions
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Ethyl acetoacetate and a range of aldehydes in the presence of ammonium acetate are converted into 1,4-dihydropyridines under mild and solvent-free conditions with good to excellent yields.
- Zolfigol, Mohammad Ali,Safaiee, Maliheh
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p. 827 - 828
(2007/10/03)
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- Chemical compounds having ion channel blocking activity for the treatment of immune dysfunction
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The present invention relates to chemical compounds having inhibitory activity on an intermediate conductance Ca 2+ activated potassium channel (IK Ca), and the use of such compounds for the treatment or alleviation of diseases or conditions relating to immune dysfunction. Moreover, the invention relates to a method of screening a chemical compound for inhibitory activity on an intermediate conductance Ca 2+ activated potassium channel (IK Ca).
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- Studies on cerebral protective agents. I. Novel 4-arylpyrimidine derivatives with anti-anoxic and anti-lipid peroxidation activities
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Novel 4-arylpyrimidine derivatives were synthesized by the oxidation of 4-aryl-1,4-dihydropyrimidines, and their effects on anti-anoxic (AA) activity in mice and anti-lipid peroxidation (ALP) activity in rat brain mitochondria were investigated. Among these compounds, ethyl 6-methyl-2-phenyl-4-(4-pyridyl)-5-pyrimidinecarboxylate (4b) has AA activity (10mg/kg, i.p.) and ethyl 6-methyl-4-(3-nitrophenyl)-2-phenyl-5-pyrimidinecarboxylate (4f) has ALP activity (73% inhibition at 10-5 g/ml). The latter compound (100mg/kg, i.p.) was also effective on arachidonate-induced cerebral edema in rats with comparable potency to that of vitamin E.
- Kuno,Sugiyama,Katsuta,Kamitani,Takasugi
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p. 1452 - 1461
(2007/10/02)
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