632-93-9Relevant articles and documents
PHOTOCATALYTIC SYSTEM AND APPLICATIONS THEREOF
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Page/Page column 38; 39, (2019/05/15)
The present invention relates to novel poly(heptazine imides), a photocatalytic system comprising such poly(heptazine imides) and a sulfur source as well as the application thereof in photocatalytic reactions.
CAN mediated mechanochemical synthesis of substituted pyridine derivatives
Khanna, Radhika,Dalal, Aarti,Kadyan, Kulbir,Kumar, Ramesh,Kumar, Parvin,Kamboj, Ramesh C.
, p. 673 - 677 (2018/07/14)
A simple, green and cost-effective protocol has been devised for the synthesis of 4-substituted-2,6-dimethyl-3,5-pyridinecarboxylates from Hantzsch-type 1,4-dihydropyridines via rapid oxidation in excellent yields using 1.5 equivalent of ceric ammonium nitrate within 15 minutes in solvent-free conditions. The method was able to furnish the products in excellent yields. The products obtained were characterized by their NMR and melting points data.
Highly crystalline poly(heptazine imides) by mechanochemical synthesis for photooxidation of various organic substrates using an intriguing electron acceptor – Elemental sulfur
Savateev, Aleksandr,Dontsova, Dariya,Kurpil, Bogdan,Antonietti, Markus
, p. 203 - 211 (2017/05/04)
Low-defect potassium poly(heptazine imide) (PHIK-BM) was engineered for application in photocatalytic oxidation of organic substrates. Mechanochemical pretreatment of a mixture of 5-aminotetrazole in LiCl/KCl eutectics using high-energy ball milling afforded a highly homogeneous mixture that, upon sequential thermolysis at 600?°C, gave nanosized particles of PHIK–BM. The photocatalytic activity of the free-standing PHIK–BM plates was assessed in the oxidation of benzyl alcohol to benzaldehyde under visible light irradiation using elemental sulfur as an electron acceptor. Both quantitative conversion (>99%) of benzyl alcohol and selectivity (>98%) with respect to benzaldehyde were achieved. The developed method was extended to aliphatic alcohol oxidation coupled with multicomponent Hantzsch 1,4-dihydropyridine synthesis. These 1,4-dihydropyridines were also photocatalytically oxidized by PHIK–BM to the corresponding substituted pyridines, with very good yields and under mild metal-free conditions.
1,4-Dihydropyridines: discovery of minimal AIEEgens and their mitochondrial imaging applications
Zhang, Wei,Wang, Na,Liu, Yan-Hong,Jiao, Shu-Yan,Zhang, Wei-Wei,Pu, Xue-Mei,Yu, Xiao-Qi
supporting information, p. 464 - 469 (2017/01/24)
Typical aggregation-induced emission enhancement fluorogens (AIEEgens) generally are designed as propeller-shaped molecules with multiple aromatic rotors. Described herein are 1,4-dihydropyridines, which have the minimum size necessary for AIEE, containing only a single ring, synthesized through a facile biocatalysis procedure. Owing to the AIEE property, intramolecular motion can be restrained by the surrounding environment, causing the radiative channel to open up. Both the fluorescence intensities and the lifetimes of the 1,4-dihydropyridine representatives increased with increasing viscosity, and high sensitivities were observed. On the basis of the single crystal X-ray structures, density functional theory (DFT) calculations were performed to explain the mechanism of the single-ring AIEE behaviour. Moreover, a few of the neutral AIEEgens were found to possess a high specificity towards mitochondria. As an example, one of the AIEEgens exhibited superior photostability and excellent storage tolerance, allowing for real-time imaging, viscosity mapping, and long-term tracking of the dynamics of the mitochondrial morphology.
Pyridine five formic acid and potassium compound and its preparation method
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Paragraph 0011; 0026; 0028; 0030, (2017/06/02)
The invention relates to a pyridine-2,3,4,5,6-pentacarbonic acid dipotassium compound and a preparation method thereof. The pyridine-2,3,4,5,6-pentacarbonic acid dipotassium compound is characterized in that a structure of the compound is shown as a following formula. The preparation method comprises the following steps: ethyl acetoacetate and acetaldehyde are performed with a chemical reaction under catalysis effect of organic amine, then is reacted with ammonia to obtain 2,4,6-trimethyl-1,4-dihydropyridine-3,5-diethyl phthalate; nitric acid oxidation is carried out to obtain 2,4,6-trimethylpyridine-3,5-diethyl phthalate; KOH hydrolysis is carried out to obtain 2,4,6-trimethylpyridine-3,5-dioctyl phthalate dipotassium; and finally KMnO4 oxidation is carried out to obtain the pyridine-2,3,4,5,6-pentacarbonic acid dipotassium compound. The compound can be used as a pH buffering agent, and has large buffer capability when pH value is 2.3. The preparation method has the advantages of simple preparation, low energy consumption, easy acquisition of raw materials, and good popularization and application prospects.
Syntheses, Structural Characterization, Reactivity, and Theoretical Studies on Some Heteroligand Oxoperoxotungstate(VI)
Das, Nandita,Chowdhury, Shubhamoy,Dutta Purkayastha, Ranendra N.
, p. 43 - 54 (2017/01/17)
White microcrystalline diamagnetic oxoperoxotungstate(VI) complexes K[WO(O2)2F]·H2O, K2[WO(O2)2(CO3)]·H2O, [WO(O2)(SO4)(H2O)2] have been synthesized from reaction of Na2WO4·2H2O with aqueous HF, solid KHCO3, aqueous H2SO4 (W:F? 1:3; W: CO3 2 ? 1:1; and W: SO4 2 ? 1:3), and an excess of 30% H2O2 at pH 7.5–8. Precipitation was completed by the addition of precooled acetone. The occurrence of terminal W?O and triangular bidentate O2 2 ?(C 2 v) in the synthesized compounds was ascertained from IR spectra. The IR spectra also suggested that the F? and SO4 2 ? ions in K[WO(O2)2F]·H2O and [WO(O2)(SO4)(H2O)2] were bonded to the WO +4 center in monodentate manner, while CO3 2 ? ion in K2[WO(O2)2(CO3)]·H2O binds the metal center in bidentate chelating fashion. The complex [WO(O2)(SO4)(H2O)2] is stable upto 110°C. The water molecule in [WO(O2)(SO4)(H2O)2] is coordinated to the WO +4 center, whereas it occurs as water of crystallization in the corresponding peroxo(fluoro) and peroxo(carbonato) compounds. Mass spectra of the compounds are in good agreement with the molecular formulae of the complexes. K2[WO(O2)2(CO3)]·H2O acts as an oxidant for bromide in the aqueous-phase bromination of organic substrates to the corresponding bromo-organics, and the complex also oxidizes Hantzsch-1,4-dihydropyridine to the corresponding pyridine derivative in excellent yield at room temperature. Density functional theory computation was carried out to compute the frequencies of relevant vibrational modes and electronic properties, and the results are in agreement with the experimentally obtained data.
Synthesis of 1,4-dihydropyridine esters using low-melting sugar mixtures as green solvents
Kumar, J. Ashwin,Shridhar, Gomathi,Ladage, Savita,Ravishankar, Lakshmy
supporting information, p. 1989 - 1998 (2016/12/09)
Several low-melting sugar mixtures (LMMs) were synthesized and used for preparation of 1,4-dihydropyridines with aldehydes, 1,3-dicarbonyl compounds, and a nitrogen source as starting materials. Good yields, low reaction times, recyclability of LMMs, and catalyst-free methodology are some of the highlights of this new protocol.
Synthesis of diethyl 4-substituted-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylates as a new series of inhibitors against yeast α-glucosidase
Niaz, Huma,Kashtoh, Hamdy,Khan, Jalaluddin A. J.,Khan, Ajmal,Wahab, Atia-Tul,Alam, Muhammad Tanveer,Khan, Khalid Mohammed,Perveen, Shahnaz,Choudhary, M. Iqbal
, p. 199 - 209 (2015/04/14)
1,4-Dihydropyridine-3,5-dicarboxylate derivatives (1-25) were synthesized in high yields via Hantzsch reaction and evaluated for their α-glucosidase inhibitory activity. Compounds 1, 2, 6-8, 11, 13-15, and 23-25 showed a potent inhibitory activity against yeast α-glucosidase with IC50 values in the range of 35.0-273.7 μM, when compared with the standard drug acarbose (IC50 = 937 ± 1.60 μM). Their structures were characterized by different spectroscopic techniques. The kinetics, selectivity, and toxicity studies on these compounds were also carried out. The kinetic studies on most active compounds 14 and 25 determined their modes of inhibition and dissociation constants Ki. Compound 14 was found to be a non-competitive inhibitor with Ki = 25.0 ± 0.06, while compound 25 was identified as a competitive inhibitor with Ki = 66.0 ± 0.07 μM.
Silica functionalized sulphonic acid coated with ionic liquid: An efficient and recyclable heterogeneous catalyst for the one-pot synthesis of 1,4-dihydropyridines under solvent-free conditions
Sharma, Pankaj,Gupta, Monika
, p. 1100 - 1106 (2015/03/04)
Silica-supported sulphonic acid catalysts were prepared and coated with ionic liquid, and their catalytic activities were evaluated for the one-pot synthesis of 1,4-dihydropyridines. Different catalysts with an ionic liquid layer (SCILLs) have been prepared with a view to determine the most active catalyst. Silica sulphonic acid coated with [BMIM][PF6] was found to be the most active catalyst and can be recycled for several runs without the loss of significant activity. It was characterized using SEM, TEM, TGA and FTIR.
Recyclable Bi2WO6-nanoparticle mediated one-pot multicomponent reactions in aqueous medium at room temperature
Paplal, Banoth,Nagaraju,Veerabhadraiah, Palakollu,Sujatha, Kodam,Kanvah, Sriram,Vijaya Kumar,Kashinath, Dhurke
, p. 54168 - 54174 (2015/02/18)
Different types of multicomponent reactions (MCRs) are reported using Bi2O3, BiVO4, and Bi2WO6 (nanoparticle) as heterogeneous catalysts. Among these, Bi2WO6 nanoparticles showed excellent reactivity for the synthesis of functionalized dihydropyridine, polyhydroquinoline, 4H-chromene and 2-amino-4H-benzo[b]pyran derivatives at ambient temperature in aqueous medium. All the reactions gave good to excellent yields in 10-45 minutes in the presence of 5 mol% (optimized) of the catalyst. The catalyst was regenerated and reused up to 5 times without losing catalytic activity. The gram scale synthesis of dihydropyridine gave the desired product in 82% yield in 2 h. This journal is
