- Aryl phenol compound as well as synthesis method and application thereof
-
The invention discloses a synthesis method of an aryl phenol compound shown as a formula (3). All systems are carried out in an air or nitrogen atmosphere, and visible light is utilized to excite a photosensitizer for catalyzation. In a reaction solvent, ArNR1R2 as shown in a formula (1) and water as shown in a formula (2) are used as reaction raw materials and react under the auxiliary action of acid to obtain the aryl phenol compound as shown in a formula (3). The ArNR1R2 in the formula (1) can be primary amine and tertiary amine, can also be steroid and amino acid derivatives, and can also be drugs or derivatives of propofol, paracetamol, ibuprofen, oxaprozin, indomethacin and the like. The synthesis method has the advantages of cheap and easily available raw materials, simple reaction operation, mild reaction conditions, high reaction yield and good compatibility of substrate functional groups. The fluid reaction not only can realize amplification of basic chemicals, but also can realize amplification of fine chemicals, such as synthesis of drugs propofol and paracetamol. The invention has wide application prospect and use value.
- -
-
Paragraph 0137-0140
(2021/05/12)
-
- Kinetics and mechanism of trichloroisocyanuric acid/NaNO2-triggered nitration of aromatic compounds under acid-free and Vilsmeier-Haack conditions
-
Kinetics and mechanism of nitration of aromatic compounds using trichloroisocyanuric acid (TCCA)/NaNO2, TCCA-N,N-dimethyl formamide (TCCA-DMF)/NaNO2, and TCCA-N,N-dimethyl acetamide (TCCA-DMA)/NaNO2 under acid-free and Vilsmeier-Haack conditions. Reactions followed second-order kinetics with a first-order dependence on [Phenol] and [Nitrating agent] ([TCCA], [(TCCA-DMF)], or [(TCCA-DMA)] >> [NaNO2]). Reaction rates accelerated with the introduction of electron-donating groups and retarded with electron-withdrawing groups, but did not fit well into the Hammett's theory of linear free energy relationship or its modified forms like Brown-Okamoto or Yukawa-Tsuno equations. Rate data were analyzed by Charton's multiple linear regression analysis. Isokinetic temperature (β) values, obtained from Exner's theory for different protocols, are 403.7?K (TCCA-NaNO2), 365.8?K (TCCA-DMF)/NaNO2, and 358?K (TCCA-DMA)/NaNO2. These values are far above the experimental temperature range (303-323?K), indicating that the enthalpy factors are probably more important in controlling the reaction.
- Bhooshan,Rajanna,Govardhan,Venkanna,Satish Kumar
-
p. 445 - 462
(2019/04/10)
-
- Silica-supported perchloric acid and potassium bisulfate as reusable green catalysts for nitration of aromatics under solvent-free microwave conditions
-
Silica-supported perchloric acid and bisulfate (SiO2/HClO4 and SiO2/KHSO4) have been developed as reusable green catalysts for nitration of aromatic compounds using NaNO2 in acetonitrile medium under conventional and solvent-free microwave conditions. The reaction times under microwave irradiation are significantly shorter than conventional method even though the yields obtained in microwave-assisted reactions are comparable with those obtained under reflux conditions.
- Kumar, M. Satish,Sriram, Y. Hemanth,Venkateswarlu,Rajanna,Sudhakar, M. Sai,Venkanna, Purugula,Saiprakash
-
supporting information
p. 59 - 67
(2017/12/26)
-
- Sodium perborate/NaNO2/KHSO4-triggered synthesis and kinetics of nitration of aromatic compounds
-
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
-
p. 6023 - 6038
(2018/09/21)
-
- Potassium Periodate/NaNO2/KHSO4-Mediated Nitration of Aromatic Compounds and Kinetic Study of Nitration of Phenols in Aqueous Acetonitrile
-
Synthesis and kinetics of potassium periodate(KIO4)/NaNO2/KHSO4)-initiated nitration of aromatic compounds have been studied in aqueous acetonitrile medium. Synthesis of nitroaromatic compounds is achieved under conventional and solvent-free microwave conditions. Reaction times in microwave-assisted reaction are comparatively less than in conventional reaction. The reaction kinetics for the nitration of phenols in aqueous bisulfate and acetonitrile medium indicated first-order dependence on [phenol], [NaNO2], and [KIO4]. An increase in [KHSO4] accelerated the rate of nitration under otherwise similar conditions. The rate of nitration increased in the solvent of high dielectric media (solvents with high dielectric constant (D)). Observed results were in accordance with Amis and Kirkwood plots [log k′ vs. (1/D) and [(D ? 1)/(2D + 1)]. These observations probably indicate the participation of anionic species and molecular or (dipolar) species in the rate-determining step. In addition, the plots of (log k′) versus volume% of organic solvent were also linear, which probably indicate the importance of both electrostatic and nonelectrostatic forces, solvent–solute interactions during nitration of phenols. Reaction rates accelerated with the introduction of electron-donating groups and retarded with electron-withdrawing groups, but results could not be quantitatively correlated with Hammett's equation and depicted deviations from linearity. These deviations could probably be attributed to cumulative effects arising inductive, resonance, and steric effects. Leffler's plot (ΔH# vs. ΔS#) was found linear indicating the compensation (cumulative) effect of both enthalpy and entropy parameters in controlling the mechanism of nitration.
- Sriram, Y. Hemanth,Fatima, Touheeth,Rajanna,Kumar, M. Satish,Raju, R. Madhusudan
-
supporting information
p. 622 - 632
(2017/06/30)
-
- Prussian Blue/NaNO2 as an Efficient Reagent for the Nitration of Phenols in Aqueous Bisulfate and Acetonitrile Medium: Synthetic and Kinetic Study
-
The reaction kinetics of Prussian blue (PB)/NaNO2 initiated for the nitration of phenols by in aqueous bisulfate and acetonitrile medium indicated first-order dependence on [phenol], [NaNO2], and [PB]. An increase in [KHSO4] accelerated the rate of nitration under otherwise similar conditions. The rate of nitration was faster in the solvent of higher dielectric constant (D). Observed results were in accordance with Amis and Kirkwood plots [log k′ vs. (1/D) and [(D ? 1)/(2D + 1)]. These findings together with the linearity of plots, log k′ versus (vol% of acetonitrile (ACN)) and mole fraction of (nx) ACN, probably indicate the importance of both eloctrostatic and nonelctrostatic forces, solvent–solute interactions during nitration of phenols. Reaction rates accelerated with the introduction of electron-donating groups and retarded with electron-withdrawing groups, which are interpreted by Hammett's theory of linear free energy relationship. Hammett's reaction constant (ρ) is a fairly large negative (ρ 0) value, indicating attack of an electrophile on the aromatic ring. Furthermore, an increase in temperature decreased the reaction constant (ρ) values. This trend was useful in obtaining isokinetic temperature (β) from Exner's plot of ρ versus 1/T. Observed β value (337.8 K) is above the experimental temperature range (303–323 K), indicating that the enthalpy factors are probably more important in controlling the reaction.
- Srinivas, Pasnoori,Suresh, Muppidi,Rajanna,Krishnaiah
-
supporting information
p. 209 - 218
(2017/02/05)
-
- Tertiary Butyl Nitrite Triggered Nitration of Phenols: Solvent- and Structure-Dependent Kinetic Study
-
Nitration of phenols with tertiary butyl nitrite (TBN) obeyed second-order kinetics with a first-order dependence on [TBN] and [phenol] under acid-free conditions. Reaction rates were significantly altered by a change in the dielectric constant and other physical properties of solvent. The rate of nitration increased with an increase in temperature (303-323 K) in different solvent media (acetonitrile, dichloroethane, CCl4, dimethyl formamide (DMF), and toluene). The rates of nitration (log k) could not fit into either Amis or Kirkwood plots [log k' vs. (1/D) or [(D - 1)/(2D + 1)], but the trends were better explained by the basic form of multivariate linear solvent energy relationships (MLSER) suggested by the Koppel and Palm approach on the one hand and the Kamlet and Taft approach on the other hand. These observations probably substantiate that cumulative contributions of basic solvent parameters (equilibrium as well as frictional solvent effects) and solvent-solute interactions for solvation of transition state during nitration of phenols. Reaction rates accelerated with the introduction of electron-donating groups and retarded with electron-withdrawing groups. Accordingly, the reactivity of structurally different phenols was found to follow the following sequence: p-OH > p-MeO > p-Me > H > m-Me > p-Cl > p-Br > m-Cl > p-NO2 > m-OH. The results are interpreted by Hammett's theory of linear free energy relationship. The reaction constant (Hammett's ρ) is a measure of the sensitivity of the reaction toward the electronic effects of the substituent. The rho (ρ) values obtained from the present experiments are fairly large negative values (ρ CH3) versus σ? or, Es or combined Taft's relationship. However, Charton's MLRA of the log k with polar, resonance, steric, hydrophobicity, and molar refractivity showing a very good linear relationship was obtained. It is of interest to note that when log kexp values are correlated with log kcal a perfect linearity is obtained with a correlation coefficient of unity, indicating the consonance between experimental and calculated rate constants in the present work.
- Kumar, M. Satish,Rajanna,Venkateswarlu,Rao, K. Lakshman
-
supporting information
p. 171 - 196
(2016/04/09)
-
- Synthesis method of 2-amino-4-chloro-6-metoxyphenol
-
The invention discloses a synthesis method of 2-amino-4-chloro-6-metoxyphenol, which belongs to the field of chemical synthesis. The method comprises the following steps of adding p-nitrophenol of nitrosonitric acid and sulfuric acid into phenol, adding methane chloride and anhydrous glacial acetic acid to obtain a mixture, then putting the mixture into a high-pressure autoclave, adding absolute ethyl alcohol and inputting hydrogen, performing pumping filtration to obtain filter residues after reaction, adding copper chloride into the filter residues, generating light green precipitation after adjusting pH through sodium hydroxide, filtering, washing the filter residues and drying to obtain the 2-amino-4-chloro-6-metoxyphenol.
- -
-
Paragraph 0004; 0007
(2016/11/14)
-
- A process for the preparation of nitro-O-cresol (by machine translation)
-
The invention discloses a method for the preparation of nitro-O-cresol, this method, in order to P-O-toluidine as raw material prepared by alkali hydrolysis of the nitro-O-cresol. The obtained P-O-cresol has high purity, measured by high-performance liquid chromatography (HPLC), area of quantitative normalization measured content of greater than 99%, yield is greater than 95%, the preparation method is simple and convenient to operate, in the method under the process conditions, repeat the plurality of batches, repeatability is good. (by machine translation)
- -
-
Paragraph 0015; 0016
(2016/10/08)
-
- Regioselective nitration of phenols and phenyl ethers using aluminium nitrate on silica as a nitrating system
-
Silica supported aluminum nitrate (Al(NO3)3·9H2O) was found to be an excellent reagent for the nitration of phenols and phenyl ethers. This procedure works efficiently on most of the examples at room temperature yielding nitro derivatives in fair to good yields with high regioselectivity. The present methodology evidenced a considerable enhancement in the reaction rate along with high o-selectivity, excellent yields, ease of handling and the simplicity in work up.
- Patil, Mahadeo R.,Mohite, Pravinkumar H.,Shisodia, Suresh,Keri, Rangappa S.
-
p. 129 - 135
(2015/06/23)
-
- Vanadium pentoxide as a catalyst for regioselective nitration of organic compounds under conventional and nonconventional conditions
-
Vanadium pentoxide is used as an efficient catalyst for regioselective nitration of aromatic compounds under conventional and nonconventional conditions such as ultrasonically assisted (USAR) and microwave-assisted reactions (MWAR). The reactions underwent smoothly and afforded good yields of products with high regioselectivity. Observed longer reaction times (about 8 h) in V2O5 catalyzed reactions reduced to (0.5/30 min) under sonication and (90 s) in the case of MWAR. When ortho position is blocked, para derivatives are obtained as end products while ortho nitro products are obtained when para position is blocked.
- Venkatesham,Reddy, K. Rajendar,Rajanna,Veerasomaiah
-
p. 921 - 926
(2014/04/03)
-
- Cyclodextrin-based artificial oxidases with high rate accelerations and selectivity
-
Three cyclodextrin derivatives with one to four 2-O-formylmethyl groups attached to the secondary rim were prepared and investigated as catalysts for the oxidation of aminophenols in buffered dilute hydrogen peroxide. The derivatives were found to be Michaelis-Menten catalysts and to give rate accelerations of up to 20,000 for the oxidation of 2-aminophenol to 2-amino-phenoxazin-3-one, and 12,000 for the oxidation of 2-amino-p-cresol to 2-nitro-p-cresol. While a range of differently substituted substrates was oxidized the success of the reaction was highly dependent on the substituent pattern. The ability of one of the new artificial enzymes to oxidize selectively one aminophenol from a mixture of two was investigated giving substrate selectivities of up to 16:1.
- Zhou, You,Lindb?ck, Emil,Pedersen, Christian M.,Bols, Mikael
-
p. 2304 - 2307
(2014/04/17)
-
- Ultrasonic and microwave-assisted synthesis of β-nitro styrenes and nitro phenols with tertiary butyl nitrite under acid-free conditions
-
Tertiary butyl nitrite (TBN) is an acid-free and safe nitrating agent that provides preferentially β-nitrostyrenes with cinnamic acids and corresponding nitro derivatives with phenols in good yields under classical conditions. However, ultrasonic and microwave-assisted reactions reduced the reaction times substantially and enhanced the yields from good to excellent. Supplemental materials are available for this article. Go to the publisher's online edition of Synthetic Communications to view the free supplemental file.
- Kumar, M. Satish,Rajanna,Reddy, K. Rajendar,Venkateswarlu,Venkanna
-
supporting information
p. 2672 - 2677
(2013/07/26)
-
- Oxalylchloride/DMF as an efficient reagent for nitration of aromatic compounds and nitro decarboxylation of cinnamic acids in presence of KNO 3 or NaNO2 under conventional and nonconventional conditions
-
Nitration of aromatic compounds and cinnamic acids with oxalylchloride/DMF afforded the corresponding nitro derivatives in the presence of KNO3 or NaNO2 under conventional and nonconventional (ultrasonic and microwave) conditions. The present methodology offers several benefits such as excellent yields, simple work-up procedure, and short reaction times. The yields obtained under present methodology are comparable with those obtained from (POCl3/DMF/KNO3 or NaNO2) and (SOCl 2/DMF/KNO3 or NaNO2) systems followed by shorter reaction times. The reaction times of sonication and microwave conditions are very shorter than those of the conventional conditions.
- Kumar, M. Satish,Reddy, K. Rajendar,Rajanna,Venkanna,Krishnaiah
-
p. 977 - 983
(2013/06/05)
-
- Eliminations from (E)-2,4-dinitrobenzaldehyde O-aryloximes promoted by R3N/R3NH+ in 70 mol% MeCN(aq). Effects of leaving group and base-solvent on the nitrile-forming transition-state
-
Elimination reactions of (E)-2,4-(NO2)2C 6H2CH=NOC6H3-2-X-4-NO2 (1a-e) promoted by R3N/R3NH+ in 70 mol % MeCN(aq) have been studied kinetically. The reactions are second-order and exhibit Broensted β = 0.80- 0.84 and |βlg| = 0.39-0.42, respectively. For all leaving groups and bases employed in this study, the β and |βlg| values remained almost the same. The results can be described by a negligible pxy interaction coefficient, pxy = δβ/pKlg = δβlg/pK-azip 0, which describes the interaction between the base catalyst and the leaving group. The negligible pxy interaction coefficient is consistent with the (E1cb) irr mechanism. Change of the base-solvent system from R 3N/MeCN to R3N/R3NH+-70 mol % MeCN(aq) changed the reaction mechanism from E2 to (E1cb)irr. Noteworthy was the relative insensitivity of the transition state structure to the reaction mechanism change.
- Cho, Bong Rae,Pyun, Sang Yong
-
supporting information
p. 1030 - 1034
(2013/07/28)
-
- Mild and efficient nitration of aromatic compounds mediated by transitionmetal complexes
-
Aromatic compounds were efficiently nitrated under facile reaction conditions by employing 69% nitric acid catalyzed by transition-metal complexes such as [Co(NH3)5Cl]Cl2, [Cu(NH 3)4]SO4, Mn(acac)3, [Ni(NH 3)6]Cl2, [Ni(en)3]S 2O3, and Hg[Co(SCN)4]. The reaction was completed smoothly at room temperature and afforded corresponding mono-nitro derivatives in quantitative yield. This new method offers efficient and facile regioselective mononitration of aromatic compounds. Taylor & Francis Group, LLC.
- Abdulla,Amina,Kumar, Y. Arun,Arifuddin,Rajanna
-
experimental part
p. 2946 - 2951
(2011/09/12)
-
- A probable hydrogen-bonded meisenheimer complex: An unusually high S NAr reactivity of nitroaniline derivatives with hydroxide ion in aqueous media
-
Observations show that nitroanilines exhibit an unusually high S NAr reactivity with OH- in aqueous media in reactions that produce nitrophenols. SNAr reaction of 4-nitroaniline (2a) in aqueous NaOH for 16 h yields 4-nitrophenol (4a) quantitatively, whereas a similar reaction of 4-nitrochlorobenzene (1a) gave 4a in 2% yield together with recovered 1a in 97%, suggesting that the leaving ability of the NH2 group far surpasses that of Cl under these conditions. An essential feature of SNAr reactions of nitroanilines is probably that the NH2 leaving group participates in a hydrogen-bonding interaction with H 2O. Density functional theory (DFT) calculations for a set of 4-nitroaniline, OH-, and H2O suggest a possible formation of a Meisenheimer complex stabilized by hydrogen-bonding interactions and a six-membered ring structure. The results obtained here contrast with conventional SNAr reactivity profiles in which nitroanilines are nearly unreactive with nucleophiles in organic solvents.
- Imoto, Mitsutaka,Matsui, Yasunori,Takeda, Motonori,Tamaki, Akihiro,Taniguchi, Hisaji,Mizuno, Kazuhiko,Ikeda, Hiroshi
-
experimental part
p. 6356 - 6361
(2011/10/05)
-
- Efficient and facile method for the nitration of aromatic compounds by nitric acid in micellar media
-
Aromatic compounds were efficiently nitrated under mild reaction conditions by employing HNO3 in the presence of anionic (sodium dodecyl sulfate, SDS), cationic (cetyl trimethyl ammonium bromide, CTAB), and nonionic (Triton-X 100) micelles. The reaction rapidly afforded corresponding mononitro derivatives in fair to good yields with high regioselectivity. This new method offers an environmentally safe reaction condition to minimize the waste products.
- Sana,Tasneem,Ali, M. Moazzam,Rajanna,Saiprakash
-
experimental part
p. 2949 - 2953
(2009/12/03)
-
- Zeolite H-Y-supported copper(II) nitrate: A simple and effective solid-supported reagent for nitration of phenols and their derivatives
-
Highly regiospecific mononitration of phenols and substituted phenols is accomplished by employing copper(II) nitrate supported on a catalytic amount of zeolite H-Y in a solid state. Copyright Taylor & Francis Group, LLC.
- Lalitha,Sivakumar
-
p. 1745 - 1752
(2008/09/20)
-
- Nitration of substituted phenols by different efficient heterogeneous systems
-
Nitration of substituted phenols were carried out by the mixture of sodium nitrite and wet SiO2 (50% w/w) in the presence of four different efficient heterogeneous systems: 1) oxalic acid dihydrate (I), 2) sodium hydrogen sulphate (II), 3) aluminum hydrogen sulphate (III) and 4) silica sulphuric acid (IV) in CH2Cl2 at room temperature and high yields. Optimum conditions for theses systems and the regioselectivities of the reactions are reported.
- Habibi, Davood,Zolfigol, Mohammad Ali,Shiri, Morteza,Sedaghat, Abdolmajid
-
-
- Synthesis and evaluation of general mechanism-based inhibitors of sulfatases based on (difluoro)methyl phenyl sulfate and cyclic phenyl sulfamate motifs
-
Several model mechanism-based inhibitors (MbIs) were designed and evaluated for their ability to inhibit sulfatases. The MbI motifs were based on simple aromatic sulfates, which are known to be commonly accepted substrates across this highly conserved enzyme class, so that they might be generally useful for sulfatase labeling studies. (Difluoro)methyl phenol sulfate analogs, constructed to release a reactive quinone methide trap, were not capable of irreversibly inactivating the sulfatase active site. On the other hand, the cyclic sulfamates (CySAs) demonstrated inhibition profiles consistent with an active site-directed mode of action. These molecules represent a novel scaffold for labeling sulfatases and for probing their catalytic mechanism.
- Hanson, Sarah R.,Whalen, Lisa J.,Wong, Chi-Huey
-
p. 8386 - 8395
(2008/02/05)
-
- Highly efficient catalytic nitration of phenolic compounds by nitric acid with a recoverable and reusable Zr or Hf oxychloride complex and KSF
-
Phenolic compounds can be nitrated with 60% nitric acid (1.2 equiv.) in the presence of catalytic amounts of a Zr or Hf oxychloride complex and montmorillonite KSF to give the corresponding nitrated products in good yields in a heterogeneous catalytic system. The co-catalyst and montmorillon ite can be easily recovered and reused in the next batch of nitration. This is a practical process for the nitration of phenolic compounds in a clean way. Wiley-VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2005.
- Shi, Min,Cui, Shi-Cong,Yin, Wan-Po
-
p. 2379 - 2384
(2007/10/03)
-
- Nitration of phenolic compounds by metal-modified montmorillonite KSF
-
The nitration of phenolic compounds with 60% nitric acid (1.2 equiv) has been carried out in the presence of metal-modified montmorillonite KSF, prepared from different metals (V, Mo, W; Sc, La, Yb, Eu, In, Bi, Ti, Zr, Hf) and KSF or nitric acid treated HKSF, as catalysts. These catalysts showed good stabilities and high catalytic activities in nitration process. In addition, these catalysts can be recovered easily and reused for many times in nitration. This process is an eco-safer and environment-benign way for clean synthesis of nitrated phenolic compounds.
- Yin, Wan-Po,Shi, Min
-
p. 10861 - 10867
(2007/10/03)
-
- Highly efficient nitration of phenolic compounds in solid phase or solution using Bi(NO3)3·5H2O as nitrating reagent
-
Bi(NO3)3·5H2O was used as an efficient nitrating reagent in the nitration of phenolic compounds to give nitrated phenols in good to high yields. The nitration reaction proceeded smoothly by grinding 1 equiv of phenol, 2-methylphenol, 4-methylphenol, or 4-chlorophenol and Bi(NO3)3· 5H2O, and the nitration of other phenolic compounds could be performed in acetone at ambient temperature (22-30 °C).
- Sun, Hong-Bin,Hua, Ruimao,Yin, Yingwu
-
p. 9071 - 9073
(2007/10/03)
-
- Supramolecular oxidation of anilines using hydrogen peroxide as stoichiometric oxidant
-
6A,6D-Di-O-(propan-2-on-1,3-diyl) α-cyclodextrin-6A,6D-dicarboxylate (2α) and 6A,6D-di-O-(propan-2-on-1,3-diyl) β-cyclodextrin-6A,6D-dicarboxylate (2β) were found to catalyze the oxidation of aromatic amines in the presence of hydrogen peroxide. The products were the corresponding nitro compounds or in some cases azo-, azoxy-, or other dimerization products. The catalysis was found to follow enzyme kinetics giving a rate increase (kcat/kuncat) of up to 1100 in the best case. Copyright
- Marinescu, Lavinia,Molbach, Merete,Rousseau, Cyril,Bols, Mikael
-
p. 17578 - 17579
(2007/10/03)
-
- Nitrophenol derivatives oxidized by cerium(IV) ammonium nitrate (CAN) and their cytotoxicity
-
Oxidation of a series of phenols with cerium(IV) ammonium nitrate (CAN) in acetonitrile undermild conditions yields the mixture of corresponding nitrophenols. In the cases of methylphenols and hydroxy-carboxylic acids, the steric effect may reduce the nitration reaction. Compounds 3 a and 4b showed selective activities to Hep 3B and Hep G2 cancer cell lines, respectively. Compound 2c showed selective activities to Hep G2 and MDA-MB-231 cancer cell lines. Further more, com pound 10b showed selective activities to Hep G2, Hep 3B, MCF-7 and MDA-MB-231 cancer cell lines.
- Pan, Wen-Bin,Wei, Li-Mei,Wei, Li-Lan,Wu, Chin-Chung,Chang, Fang-Rong,Wu, Yang-Chang
-
p. 581 - 588
(2007/10/03)
-
- A New Method for Nitration of Phenolic Compounds
-
Phenolic compounds can be nitrated by 65% nitric acid in the presence of catalytic amounts of montmorillonite KSF and bismuth(III) nitrate to give the corresponding nitrated products in good yields in a heterogeneous phase. The co-catalyst of KSF and Bi(NO3)3 can be easily recovered and reused in the next batch of nitration.
- Shi, Min,Cui, Shi-Cong
-
p. 1197 - 1202
(2007/10/03)
-
- Regio-selective mono nitration of phenols with ferric nitrate in room temperature ionic liquid
-
The mono nitration of phenols with ferric nitrate has been achieved in high regio-selectivities in 1-3 h at 30-60°C using the ionic liquid 1,3-di-n-butylimidazolium tetraflouroborate [bbim]BF4 as the solvent. In particular, excellent para selectives of the order of 76-86% for unsubstituted, ortho and meta-substituted phenols were observed.
- Rajagopal,Srinivasan
-
p. 961 - 966
(2007/10/03)
-
- Selective nitration of aromatic compounds with bismuth subnitrate and thionyl chloride
-
Bismuth subnitrate/thionyl chloride have been found to be an efficient combination of reagents for nitration of a wide range of aromatic compounds in dichloromethane. Phenols, in particular, were easily mononitrated and dinitrated with the reagents by controlling the stoichiometry.
- Muathen, Hussni A.
-
p. 593 - 598
(2007/10/03)
-
- QSAR for the cytotoxicity of 2-alkyl or 2,6-dialkyl, 4-X-phenols: The nature of the radical reaction
-
In a continuation of studies on the radical mediated toxicity of phenols to leukemia cells, a set of di- and tri-substituted phenols with mostly alkyl substituents in the ortho position were examined. These analogs are similar in structure to the commercial antioxidants BHA and BHT. A QSAR analysis of their growth inhibitory constants led to the formulation of this simple but unusual equation based on 18 congeners: log 1/C = -0.47Es-2 + 2.42RR + 2.43; r3 = 0.934 ES-2 is the Taft steric parameter for the larger of the two ortho substituents while ER is Otsu's radical parameter, which was originally defined to correlate radical reactions.
- Selassie, Cynthia D.,Verma, Rajeshwar P.,Kapur, Sanjay,Shusterman, Alan J.,Hansch, Corwin
-
p. 1112 - 1117
(2007/10/03)
-
- Hydroxylation of Nitroarenes with Alkyl Hydroperoxide Anions via Vicarious Nucleophilic Substitution of Hydrogen
-
Rhone-Poulenc Polska Ltd., ul. Grzybowska 80/82, 00-844 Warszawa, Poland Garbo- and heterocyclic nitroarenes react with anions of tert-butyl and cumyl hydroperoxides in the presence of strong bases to form substituted o- and p-nitrophenols. The reaction usually proceeds in high yields and is of practical value as a method of synthesis and manufacturing of nitrophenols. Orientation of the hydroxylation can be controlled to a substantial extent by selection of the proper conditions. Basic mechanistic features of this process were clarified.
- Makosza, Mieczyslaw,Sienkiewicz, Krzysztof
-
p. 4199 - 4208
(2007/10/03)
-
- Heteroacetic acid derivatives
-
Disclosed are compounds of formula STR1 wherein R is hydroxy, esterified hydroxy or etherified hydroxy; R1 is halogen, trifluoromethyl or lower alkyl; R2 is halogen, trifluoromethyl or lower alkyl; R3 is halogen, trifluoromethyl, lower alkyl, aryl, aryl-lower alkyl, cycloalkyl or cycloalkyl-lower alkyl; or R3 is the radical STR2 wherein R8 is hydrogen, lower alkyl, aryl, cycloalkyl, aryl-lower alkyl or cycloalkyl-lower alkyl; R9 is hydroxy or acyloxy; R10 represents hydrogen or lower alkyl; or R9 and R10 together represent oxo; R4 is hydrogen, halogen, trifluoromethyl or lower alkyl; X is --NR7, S or O; W is O or S; R5 represents hydrogen, lower alkyl or aryl-lower alkyl;and R6 represents hydrogen; or R5 and R6 together represent oxo provided that X represents --NR7; R7 represents hydrogen or lower alkyl; Z represents carboxyl, carboxyl derivatized as a pharmaceutically acceptable ester or as a pharmaceutically acceptable amide; and pharmaceutically acceptable salts thereof; which are useful as hypocholesteremic agents.
- -
-
-
- Studies on photochemical reactions of air pollutants. XIII. Formation of nitrophenols by the reactions of three toluene oxides with nitrogen dioxide in air
-
Three toluene oxides reacted with nitrogen dioxide in air to give nitrocresols. 1-Methylbenzene oxide (1) and 3-methylbenzene oxide (2) gave the same nitrocresols, including 2-methyl-6-nitrophenol (1b) and 2-methyl-4-nitrophenol (1c), while 4-methylbenzene oxide (3) gave only 4-methyl-2-nitrophenol (3b). Irradiation with a xenon lamp through a Pyrex filter (cut-off below 290 nm) did not affect the product distribution. Only 1-methylbenzene oxide (1) generated fog when it was brought into contact with nitrogen dioxide in air.
- Nojima,Isogami
-
p. 2426 - 2429
(2007/10/02)
-
- Calcium nitrate - A new nitrating agent for nuclear nitration of substituted phenols
-
Nitration of selected substituted phenols using Calcium Nitrate as a new nitrating agent is reported, compared with sodium nitrate and the dependance of product selectivity on temperature is demonstrated.
- Bisarya,Joshi,Holkar
-
p. 1125 - 1137
(2007/10/02)
-
- Reaction of cerium(IV) ammonium nitrate with simple phenols in a silica gel matrix
-
The oxophilicity of cerium(IV) ammonium nitrate is moderated by the addition of hydrogen peroxide.The reaction with simple phenols becomes regioselective when carried out in a silica gel matrix.The methodology has been employed for the synthesis of new functionalized terphenyls and biphenyls.
- Chakrabarty, K,Chawla, H M,Suresh, V V
-
p. 464 - 466
(2007/10/02)
-
- Preparation of and addition of carbanions to 6-methyl-6-nitrocyclohexa-2,4-dienones
-
Nitration of 2-methylphenols with nitric acid and trifluoroacetic anhydride in ether at -78 deg C gives 6-methyl-6-nitrocyclohexa-2,4-dienones that can be isolated.Carbanions add to 5,6-dimethyl-6-nitrocyclohexa-2,4-dienone to give the 5-substituted 2,3-dimethyl-2-nitrocyclohex-3-enone anion, which, with additional carbanion, gives the 5-substituted 2,3-dimethylphenoxide anion by elimination of nitrous acid.Key words: nitration, dienone, addition, carbanion, nucleophilic.
- Fischer, Alfred,Henderson, George N.,Sankararaman, S.
-
p. 1244 - 1246
(2007/10/02)
-
- FORMATION OF DIENONES ON THE REACTION OF CRESOLS, XYLENOLS, AND 2-NAPHTHOL WITH NITROGEN DIOXIDE: OBSERVATION OF KETO TAUTOMERS OF NITROPHENOLS
-
Reaction of o- and p-cresol, the xylenols, and 2-naphthol with nitrogen dioxide gives nitrocyclohexadienones and nitrophenols.Secondary nitrodienones, the keto tautomers of the nitrophenols, have been observed in several cases and are intermediates in the formation of the nitrophenols.
- Fischer, Alfred,Mathivanan, N.
-
p. 1869 - 1872
(2007/10/02)
-
- NITRATION OF PHENOLS WITH NITRATES IN A TWO-PHASE SYSTEM
-
Phenols are easily nitrated at room temperature, with good selectivity, by dilute nitric acid or metallic nitrates, in an acidic two-phase system, even without phase transfert catalyst.The results, in these experimental conditions, suggest an electron transfer mechanism for this reaction.
- Gaude, D.,Goaller, R. Le,Pierre, J. L.
-
-
- ipso Nitration. XXIV. Nitration of 2-methylphenols. Formation and rearrangement of 6-methyl-6-nitrocyclohexa-2,4-dienones
-
Nitration of o-cresol and some mono-, di-, and trimethyl derivatives in acetic anhydride at -60 deg C gives 6-methyl-6-nitrocyclohexa-2,4-dienones.The dienones are more labile than the isomeric 4-methyl-4-nitrocyclohexa-2,5-dienones and, if the 2-position of the dienone is not blocked, undergo regiospecific rearrangement to 6-nitro-o-cresols. 2,3,6-Trimethyl- and 2,3,5,6-tetramethylphenol also give a 2,5-dienone with nitro attached to a secondary carbon.
- Cross, Gordon G.,Fischer, Alfred,Henderson, George N.,Smyth, Trevor A.
-
p. 1446 - 1451
(2007/10/02)
-
- SYNTHESIS OF NITROPHENOLS
-
Nitrophenols are prepared from halonitrobenzenes or nitroanilines by treatment with aqueous base.
- Anderson, James S.,Brown, Keith C.
-
p. 233 - 236
(2007/10/02)
-
- Photochemical Nucleophilic Substitution Reactions of Methyl Substituted Derivatives of p- and o-Nitroanisole
-
Photosubstitution reactions of several methyl substituted derivatives of p- and o-nitroanisole with hydroxide ion were investigated.The methyl substituent seemed to show an uncertain (probably electronic) effect in addition to the steric effect for the replacement of both the methoxy and the nitro groups.Mainly, the replacement reaction of the nitro group is discussed.
- Sawaura, Masaki,Mukai, Toshio
-
p. 3213 - 3214
(2007/10/02)
-
- IPSO NITRATION: NITRATION OF 2-ALKYLPHENOLS IN ACETIC ANHYDRIDE. FORMATION OF 6-ALKYL-6-NITROCYCLOHEXA-2,4-DIENONES
-
Low temperature nitration of 2-alkylphenols in acetic anhydride gives 6-alkyl-6-nitrocyclohexa-2,4-dienones.The dienones undergo a regiospecific rearrangement to give o-nitrophenols
- Fischer, Alfred,Henderson, George N.
-
p. 4661 - 4662
(2007/10/02)
-
