- Sodium perborate/NaNO2/KHSO4-triggered synthesis and kinetics of nitration of aromatic compounds
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Sodium perborate (SPB) was used as efficient green catalyst for NaNO2/KHSO4-mediated nitration of aromatic compounds in aqueous acetonitrile medium. Synthesis of nitroaromatic compounds was achieved under both conventional and solvent-free microwave conditions. Reaction times were comparatively shorter in the microwave-assisted than conventional reaction. The reaction kinetics for nitration of phenols in aqueous bisulfate and acetonitrile medium indicated first-order dependence on [Phenol], [NaNO2], and [SPB]. Reaction rates accelerated with introduction of electron-donating groups but retarded with electron-withdrawing groups. Kinetic results did not fit well quantitatively with Hammett’s equation. Observed deviations from linearity were addressed in terms of exalted Hammett’s constants (σˉ or σeff), para resonance interaction energy (ΔΔGp) parameter, and Yukawa–Tsuno parameter (r). This term provides a measure of the extent of resonance stabilization for a reactive structure that builds up charge (positive) in its transition state. The observed negative entropy of activation (?ΔS#) suggests greater solvation and/or cyclic transition state before yielding products.
- Rajanna,Muppidi, Suresh,Pasnoori, Srinivas,Saiprakash
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p. 6023 - 6038
(2018/09/21)
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- A phenol compound green nitration method and application
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The invention discloses a green nitrification method and application for a phenolic compound, belonging to the technical field of organic synthesis. The method provided by the invention comprises the following steps: with the phenolic compound as a raw material, dissolving the phenolic compound into a solvent at room temperature, adding sodium nitrite, then dropwise adding hydrogen peroxide into the obtained reaction solution, adding water-soluble metalloporphyrin at room temperature and starting reaction, carrying out nitrification reaction under stirring, then carrying out extraction by using an organic solvent, and carrying out vacuum concentration and column chromatographic separation so as to obtain a target product. The nitrification method provided by the invention has the advantages of mild reaction conditions, no need of heating, convenient operation and easy treatment of products. The green nitrification reaction is suitable for the phenolic compound.
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Paragraph 0052; 0053; 0054; 0055; 0556; 0057; 0058; 0059
(2017/08/24)
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- Environment-friendly bionic catalytic nitration method for phenolic compound
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The invention discloses an environment-friendly bionic catalytic nitration method for a phenolic compound and belongs to the technical field of organic synthesis. The method provided by the invention comprises the steps of dissolving the phenolic compound, which serves as a raw material, in a solvent at normal temperature, adding sodium nitrite into the solution, then, dropwise adding hydrogen peroxide into the reaction solution, adding metal-doped Al-MCM-41 molecular sieves into the reaction solution at normal temperature so as to start a reaction, carrying out stirring so as to carry out a nitration reaction, and then, carrying out suction filtration, organic solvent extraction, depressurized concentration and column chromatography separation, thereby obtaining a target product. According to the nitration method disclosed by the invention, the reaction conditions are mild, heating is not required, the operation is convenient, and the product is easy to treat. The nitration method is applicable to an environment-friendly bionic catalytic nitration reaction for phenolic compounds.
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Paragraph 0045-0046
(2017/06/19)
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- Biomimetic Nitration of Phenols Using Metalloporphyrins/H2O2/NO2 -
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An efficient metalloporphyrins/H2O2/NO2 - nitration of phenols has been developed. The total yield of nitrophenol could reach up to 55.1 %, which is about 4 and sixfold higher than that of horse radish peroxidase catalysis and peroxynitrite nitration, respectively. Furthermore, the nitration system attained an enhanced regioselectivity of 1.0 o/p ratio, and exhibited a good substrate scope of monophenols. This protocol is environmentally friendly compared with HNO3/H2SO4 nitration, and stable, inexpensive and organic solvent tolerant compared with enzyme catalytic nitration and peroxynitrite nitration reaction. Graphical Abstract: [Figure not available: see fulltext.]
- Sun, Weizhi,Liu, Yaojie,Zhang, Haibo,Xian, Mo,Liu, Huizhou
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p. 1991 - 1999
(2015/12/24)
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- Heteropolyacids as an efficient and reusable catalytic system for the regiospecific nitration of phenols with metal nitrates
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Highly regiospecific mononitration of phenols and substituted phenols is accomplished employing a metal nitrate and a catalytic amount of heteropolyacid in acetonitrile. An xclusive ortho-selectivity was observed with excellent yields. A variety of metal nitrates were used to obtain o-nitrophenols exclusively in good to excellent yields. The use of heteropolyacid is key for the selectivity observed.
- Baghernejad, Bita,Heravi, Majid M.,Oskooie, Hossein A.,Bamoharram, Fatemeh F.
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experimental part
p. 145 - 152
(2012/04/18)
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- Nitration of phenolic compounds by antimony nitrate
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Antimony nitrate is new compound to be an efficient nitration reagent in the nitration of phenolic compounds with high yields. This producerworks efficiently onmost of the examples, as a grinding nitration reaction, proceed very fast (～1 min) and thermogenic. Copyright Taylor & Francis Group, LLC.
- Jirandehi, Hassan Fathinejad,Mirzaeian, Marjan
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experimental part
p. 284 - 286
(2011/07/08)
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- Urolithin as a Converging Scaffold Linking Ellagic acid and Coumarin Analogues: Design of Potent Protein Kinase CK2 Inhibitors
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Casein kinase2 (CK2) is a ubiquitous, essential, and highly pleiotropic protein kinase; its abnormally high constitutive activity is suspected to underlie its pathogenic potential in neoplasia and other relevant diseases. Previously, using different in silico screening approaches, two potent and selective CK2 inhibitors were identified by our group: ellagic acid, a naturally occurring tannic acid derivative (Ki=20nM) and 3,8-dibromo-7-hydroxy-4-methylchromen-2-one (DBC, Ki=60nM). Comparing the crystallographic binding modes of both ellagic acid and DBC, an X-ray structure-driven merging approach was taken to design novel CK2 inhibitors with improved target affinity. A urolithin moiety is proposed as a possible bridging scaffold between the two known CK2 inhibitors, ellagic acid and DBC. Optimization of urolithinA as the bridging moiety led to the identification of 4-bromo-3,8-dihydroxy-benzo[c]chromen-6-one as a novel, potent and selective CK2 inhibitor, which shows a Ki value of 7nM against the protein kinase, representing a significant improvement in affinity for the target compared with the two parent fragments. Two become one: Comparing the crystallographic binding modes of ellagic acid (red) and 3,8-dibromo-7-hydroxy-4-methylchromen-2-one (DBC; blue), an X-ray structure-driven merging approach to the design of novel casein kinase2 (CK2) inhibitors was taken. Using this strategy, a potent and selective urolithin derivative, 4-bromo-3,8-dihydroxy-benzo[c]chromen-6-one was identified, which exhibits a Ki value of 7nM against CK2.
- Cozza, Giorgio,Gianoncelli, Alessandra,Bonvini, Paolo,Zorzi, Elisa,Pasquale, Riccardo,Rosolen, Angelo,Pinna, Lorenzo A.,Meggio, Flavio,Zagotto, Giuseppe,Moro, Stefano
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experimental part
p. 2273 - 2286
(2012/04/11)
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- KHSO4 as an efficient catalytic system for the regiospecific nitration of phenols with metal nitrates
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Highly regiospecific mononitration of phenol and substituted phenols was accomplished employing a metal nitrate and a catalytic amount of KHSO4 in acetonitrile. An exclusive ortho-selectivity was observed with excellent yields. A variety of metal nitrates were used to obtain o-nitrophenols exclusively in good to excellent yields. The use of KHSO4 is key for the selectivity observed.
- Baghernejad, Bita,Oskooie, Hossein A.,Heravi, Majid M.,Beheshtiha, Yahia Sh.
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experimental part
p. 393 - 396
(2010/10/02)
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- Anti-arteriosclerotic agents
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Novel substituted arylene compounds and methods for their preparation and use are disclosed. These new compounds are useful as anti-arteriosclerotic agents.
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