76258-20-3Relevant articles and documents
Superparamagnetic core-shell metal–organic framework Fe3O4@Ni-MOF as efficient catalyst for oxidation of 1,4-dihydropyridines using hydrogen peroxide
Janani, Marzieh,Senejani, Masumeh Abdoli,Isfahani, Tahereh Momeni
, (2021/07/21)
A facile and efficient method was described for oxidation of some 3,5-diacyl or 3,5-diester 1,4-dihydropyridines using H2O2 in the presence of superparamagnetic core-shell metal–organic framework Fe3O4@Ni-MOF. The Fe3O4@Ni-MOF has been obtained by Step-by-Step method in which magnetic Fe3O4 magnetic nanoparticles were coated with Ni-MOF using a mercaptoacetic acid linker. The synthesized catalyst was characterized using thermogravimetric analysis, FT-IR spectroscopy, powder X-ray diffraction, field emission scanning electron microscopy and energy-dispersive X-ray analysis. The novel superparamagnetic core-shell metal–organic framework Fe3O4@Ni-MOF revealed high efficiency for oxidation of various 1,4-dihydropyridines using hydrogen peroxide. The Box–Behnken design matrix and the response surface method were applied to investigate the optimization of the reaction conditions. The conditions for optimal reaction yield and time were: amount of catalyst ≈17 mmol, temperature ≈78°C and amount of hydrogen peroxide ≈ 1 ml. A variety of 3,5-diacyl or 3,5-diester 1,4-dihydropyridines with different substituted functional groups have been converted to corresponding pyridines with good to excellent isolated yields using H2O2 and Fe3O4@Ni-MOF. The catalyst was reused up to five times for the oxidation of 1,4-dihydropyridines without a significant loss in catalytic activity. The short reaction times, simplicity of method, good to excellent yields and reusability of catalyst were some advantages of the proposed procedure.
Graphite oxide-promoted one-pot synthesis and oxidative aromatization of Hantzsch 1,4-dihydropyridines
Mirza-Aghayan, Maryam,Asadi, Fatemeh,Boukherroub, Rabah
, p. 1919 - 1924 (2015/02/19)
A new and efficient method for the one-pot synthesis of pyridine compounds using three-component Hantzsch synthesis in high yields using graphite oxide, a readily available and inexpensive material, as a mild and efficient agent is described. Graphical Abstract: [Figure not available: see fulltext.]
An efficient transition-metal-chloride/sodium-nitrite/TEMPO catalytic system for aerobic oxidative aromatisation of Hantzsch 1,4-dihydropyridines
Lou, Bin-Hui,Chen, Shu-Bin,Wang, Jian,Chen, Ying,Li, Jing-Hua
, p. 409 - 412 (2013/09/12)
A facile and efficient transition-metal-chloride/sodium-nitrite/TEMPO catalytic system for aerobic oxidative aromatisation of Hantzsch 1,4-dihydropyridines in high yields under mild conditions is described.
Remarkably fast and selective aromatization of Hantzsch esters with MoOCl4 and MoCl5: A chemical model for possible biologically relevant properties of molybdenum-containing enzymes
Litvic, Mladen,Regovic, Maja,Smic, Karolina,Lovric, Marija,Filipan-Litvic, Mirela
experimental part, p. 3676 - 3681 (2012/07/17)
Mo(VI) and Mo(V) salts both react selectively with Hantzsch esters to produce substitute pyridines in good-to-excellent yield (75-99%). The remarkable reactivity and selectivity of MoOCl4 under reflux of acetonitrile and MoCl5 in dichloromethane at room temperature encouraged us to propose that molybdenum-containing enzymes (such as xanthine or aldehyde oxidase) also participate to some degree in the metabolism of 1,4-dihydropyridine drugs in the liver analogous to NADH in the respiratory chain.
A highly efficient biomimetic aromatization of Hantzsch-1,4-dihydropyridines with t-butylhydroperoxide, catalysed by iron(III) phthalocyanine chloride
Filipan-Litvic, Mirela,Litvic, Mladen,Vinkovic, Vladimir
experimental part, p. 9276 - 9282 (2009/04/05)
Rapid aromatization of Hantzsch-1,4-DHPs with t-butylhydroperoxide catalysed by iron(III) phthalocyanine chloride is described. The reaction proceeds smoothly at room temperature within 1-35 min and the products of high purity were isolated in excellent yields. To explain the reactivity of this catalytical system plausible mechanism have been proposed to involve formation of high-valent oxoferryl species as in cytochrome P450 itself.
An efficient, metal-free, room temperature aromatization of Hantzsch-1,4-dihydropyridines with urea-hydrogen peroxide adduct, catalyzed by molecular iodine
Filipan-Litvi?, Mirela,Litvi?, Mladen,Vinkovi?, Vladimir
, p. 5649 - 5656 (2008/09/21)
A mild, highly efficient and metal-free synthetic method for aromatization of 1,4-dihydropyridines employing urea-hydrogen peroxide adduct as oxidant catalyzed by 20 mol % of molecular iodine was developed. The reaction was carried out in ethyl acetate at room temperature and the products were isolated in high to excellent yields. A plausible free-radical mechanism is proposed based on results obtained with derivatives having alkyl and aryl substituents in the 1,4-dihydropyridine ring.
Rapid, efficient, room temperature aromatization of Hantzsch-1,4-dihydropyridines with vanadium(V) salts: superiority of classical technique versus microwave promoted reaction
Filipan-Litvi?, Mirela,Litvi?, Mladen,Vinkovi?, Vladimir
, p. 10912 - 10918 (2008/12/23)
The aromatization of 1,4-dihydropyridines (1,4-DHPs) employing group 4 (Zr and Hf) and 5 (V, Nb, Ta) elements of periodic system has been studied. The reaction with VOCl3 in dichloromethane at room temperature afforded products, substituted pyridines, in high-to-excellent yield. For the first time, the formation of charge-transfer complexes (CTCs) has been evidenced in preorganization step between 1,4-DHP and oxidant before electron transfer. The CTC has been formed only in neutral solvents such as dichloromethane and is characterized by intensive coloration. The aromatization of 1,4-DHP with V2O5 in refluxing acetic acid has found to be superior over microwave promoted reaction in solventless media. The only reasonable explanation was found in polymeric structure of V2O5, which slowly transfer energy of microwaves needed for the activation of the reactants. The solvent polarity dependent oxidative dealkylation of 4-n-propyl-1,4-DHP has been discovered. Unexpectedly, the reaction in acetic acid afforded only 33% of dealkylated product compared to 91% obtained in dichloromethane under the same reaction conditions.
Silica chromate as a novel oxidizing agent for the oxidation of 1,4-dihydropyridines
Zolfigol, Mohammad Ali,Salehi, Peyman,Ghorbani-Choghamarani, Arash,Safaiee, Maliheh,Shahamirian, Mozhgan
, p. 1817 - 1823 (2008/02/02)
Silica chromate easily converts 1,4-dihydropyridines to their corresponding pyridines in the presence of NaHSO4·H2O and wet SiO2 in dichloromethane at room temperature in good to excellent yields. Copyright Taylor & Francis Group, LLC.
BIFC and QFC promoted rapid and cleaner aromatization of 1,4-dihydropyridines under solvent-free condition
Sivamurugan, Vajiravelu,Vinu, Ajayan,Suresh, Valiyaveettil,Palanichamy, Muthaiyahpillai,Murugesan, Velayutham
, p. 973 - 977 (2008/03/29)
(Chemical Equation Presented) This communication expresses aromatisation of 1,4-dihydropyridines to pyridine derivatives with the help of alumina supported benzimidazolium fluorochromate (BIFC) and quinolinium fluorochromate (QFC) as oxidants under solvent-free microwave irradiation. Moderate to excellent yield (80-98%) of pyridine derivatives were achieved by this methodology.
A facile aromatisation of 1,4-dihydropyridines by ammonium nitrate in acetic acid
Awachat, Moreshwar M.,Shaikh, Ajam C.,Ganjave, Nitin V.,Chavan, Subhash P.,Shivakumar,Kalkote, Uttam R.
, p. 193 - 194 (2008/02/09)
The oxidation of 1,4-dihydropyridines to pyridines with ammonium nitrate as an oxidant in the presence of acetic acid proceeds in excellent yield.
