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Name Reactions
Published in Benny K.G. Theng, Clay Mineral Catalysis of Organic Reactions, 2018
Zonouz and coworkers (Zonouz and Hosseini 2008; Zonouz and Sahranavard 2010), for example, obtain 1,4-dihydropyridine derivatives (3) in high yields by the Hantzsch synthesis of various aryl aldehydes (1) with ethyl acetoacetate (2) and ammonium acetate (or ammonia) in ethanol (or water), according to Scheme 5.15, using K10 montmorillonite as the catalyst. K10-supported Ni0 nanoparticles are similarly effective in catalyzing the solvent-free synthesis of Hantzsch polyhydroquinoline from the condensation of aldehydes, dimedone, ethyl acetoacetate, and ammonium acetate at room temperature (Saikia et al. 2012). Earlier, Maquestiau et al. (1991) reported that K10-supported cupric nitrate or claycop (cf. Chapter 4) was an efficient catalyst for the aromatization of Hantzsch 1,4-dihydropyridines under ultrasonic irradiation.
Antihypertensive Drugs: Controlling Blood Pressure
Published in Richard J. Sundberg, The Chemical Century, 2017
A large number of dihydropyridines have been investigated as CCBs. The first and second generation, as represented by nifedipine and nicardipine, were fast-acting but with fairly short durations of action. Several studies suggested that the fast-acting dihydropyridines may be associated with increased risk of heart attacks. Controversy arose in the mid-1990s about the studies indicating these relationships.13 They were reformulated in extended release forms in response to the problems. In 1996, the FDA approved continued use, but required a warning on potential hazards.14 The third generation drugs including amlodipine and nitrendipine have improved pharmacodynamics profiles. Amlodipine is used extensively in fixed combinations with the other types of antihypertensive drugs. The fourth generation drugs have still longer periods of effectiveness, which was achieved by introducing more lipophilic substituents.15 Some of the differential effects of the various dihydropyridines may be the result of discrimination between the types and location of calcium channels that are affected.16
Oxide Nanoparticles in Heterogeneous Catalysis
Published in Varun Rawat, Anirban Das, Chandra Mohan Srivastava, Heterogeneous Catalysis in Organic Transformations, 2022
Garima Sachdeva, Jyoti Dhariwal, Monika Vats, Varun Rawat, Manish Srivastava, Anamika Srivastava
1,4-Dihydropyridines are the class of drugs that helps in calcium channel modulation and is common to many bioactive compounds. A simple and effective protocol was developed by Murthy et al. for the synthesis of 1,4-dihydropyridines (Hantzsch esters). Treatment of substituted aromatic aldehyde, ethyl acetoacetate, and ammonium acetate in ethanol in the presence of copper ferrite nanoparticles at room temperature afforded corresponding 1,4-dihydropyridine [84]. The methodology provides several advantages like low catalyst loading, short reaction times, high product yields, and easy catalyst separation.
Green synthesis, molecular docking and anticancer activity of novel 1,4-dihydropyridine-3,5-Dicarbohydrazones under grind-stone chemistry
Published in Green Chemistry Letters and Reviews, 2020
Sobhi M. Gomha, Zeinab A. Muhammad, Hassan M. Abdel-aziz, Islam K. Matar, Abdelaziz A. El-Sayed
Although, chemotherapy is useful for liver cancer but the drug resistance development occurs in metastatic cancers (8,9). Resistance to several similar drugs is often observed after sporadic or repeated exposure of tumor cells to only one chemotherapeutic agent (10). The need for effective treatment encouraged the search for design and summarization of new agents as a result of multiple drug resistance in cancer chemotherapy. 1,4-Dihydropyridines are important class of compounds in the field of pharmaceuticals and drugs. Researches on dihydropyridine and its synthetic analogs has revealed that they possess many biological activities such as vasodilates, antihypertensive, anti-inflammatory, anti-ischemic agents, antianginal, antithrombotic, anticonvulsant, antimicrobial activities (11–18). Moreover, many heterocyclic hydrazones represents an interesting class of hetero compounds with a broad spectrum of biological activities, analgesic, anti-inflammatory, antimicrobial, antitubercular, antiplatelet, anticonvulsant, antimalarial and antiviral activities (19–23). It is quite interesting to note that the 1,4-dihydropyridine and hydrazine derivatives have gained prominence in the recent years for cancer chemotherapy (24–30). 1,4-Dihydropyridines have been proved to be a new class of multidrug resistance (MDR) reversals in cancer treatment (31).
Ultrasound-promoted green synthesis of 1,4-dihydropyridines using fuctionalized MWCNTs as a highly efficient heterogeneous catalyst
Published in Green Chemistry Letters and Reviews, 2018
In the present work, we wish to report a new synthetic method for preparation of 1,4- dihydropyridine derivatives in the presence of MWCNTs@meglumine as a new high efficient and reusable catalyst. The catalyst was prepared through a three-step process. Firstly, raw MWCNTs were oxidized and then, the generated carboxylic groups were converted to –COCl using SOCl2. Finally, the reaction of MWCNTs-COCl with meglumine, lead to formation of MWCNTs@meglumine through the nucleophilic substitution reaction between –OH or –NHMe groups of meglumine and acyl chloride groups on CNT surfaces (Scheme 2). In Fact, this process is a method for immobilization of meglumine as a highly soluble catalyst on CNT surfaces, for preparing an effective heterogeneous and reusable catalyst, in following of green chemistry protocol.
Synthesis, crystal structure, Hirshfeld surface, biological evaluation, DFT and molecular docking studies of unsymmetrical 3-allyl-5-ethyl-1,4-dihydro-2,6-dimethyl-4-phenyl pyridine-3,5-dicarboxylate derivatives
Published in Molecular Physics, 2023
K. Arulvani, R. Venkateswaramoorthi, S. Gunavathi, S. Bharanidharan
Much of the literature revealed that the Hantzsch method uses the aldehyde, ammonium acetate, and the two same esters for the synthesis of 1,4-dihydropyridine using a catalyst [6,7]. A literature survey reveals that the dihydropyridine represents an important class of heterocyclic skeletons which prevalently exist in biologically active agents and pharmaceutically important molecules [8–12]. This 1,4-dihydropyrindine have biological property such as cytotoxicity [13], antioxidant [14], hypertensive [15], anticonvulsant [16], antimicrobials [17–19], anticholinesterase [20], anticancer [21,22], antibreast cancer [23] activities. Researchers modified the structure of 1,4-dihydropyridine by using different esters, and reaction conditions [24,25] and their biological activities are significantly increased in different activities of antiproliferative [26], calcium channel antagonists [27], calcium channel blockers [28], anticancer [29,30], antioxidant [31,32], antitubercular [33], calcium modulator [34] activities. Hence many researchers [35,36] concentrated on the synthesis of unsymmetrical 1,4-dihydropyridine derivatives using different reaction conditions and catalysts such as 3,4,5-trifluorobenzeboronic acid [37], FeF3 [38], bismuth nitrate [35], poly(4-vinylpyridinium)hydrogen sulphate [39], L-proline [40], cellulose sulphuric acid [41], cobalt nanoparticles [42], tetrabutylammoniumhexatungstate [43], H5BW12O40 [44], nicotinic acid [45]. The above methods contain some drawbacks such as dangerous solvents expensive reagents, long reaction times, and difficult workup process. Based on that we are interested to construct the unsymmetrical 1,4-dihydropyridine by a simple catalyst of Ceric Ammonium acetate. Because it has been owned to various advantages with powerful eco-friendly catalysts and an important role in the synthesising drug molecules (Figure 1), the construction of C–C, and C-X bonds [46–48] and various organic transformations including Lewis’s acid catalyst [49,50]. Ceric ammonium nitrate is a potent catalyst in synthesising various bio molecules because it has excellent solubility in water, eco-friendly high reactivity, electron transfer, and Lewis acidic properties [51]. In the present investigation, the Density-functional theory (DFT) method provided useful information regarding the structure and conformation of molecules if utilised in conjunction with quantum chemical calculations. Hence, the DFT method is a successful theory to calculate the structural, Physico-chemical, electronic and optical properties of organic molecules. In the light of above importance and in further continuation of this study to develop novel drug agents, the study is aimed to design, molecular docking, and synthesise of 3-allyl-5-ethyl-1,4-dihydro-2,6-dimethyl-4-phenyl pyridine-3,5-dicarboxylates as prospective antimicrobial agents.