- Water concentration dependent photochemistry of ketoprofen in aqueous solutions
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Ketoprofen is an important photosensitive drug molecule that has received much attention for the study of its photochemistry in different solvents. In this paper, nanosecond time-resolved resonance Raman spectroscopy was utilized to investigate the photochemistry of ketoprofen in aqueous solutions with varying water concentrations. The rate constants and reaction mechanism of ketoprofen are strongly dependent on the concentration of the solvent. In neat acetonitrile and solvents with low concentrations of water (like water-acetonitrile ≤ 1:1, v/v), ketoprofen exhibits mostly benzophenone-like photochemistry to generate a triplet state which in turn produces a ketyl radical-like species by a hydrogen abstraction reaction. However, in solvents with very high concentrations of water (such as water-acetonitrile ≥ 9:1, v/v), the triplet state ketoprofen is observed first and then undergoes a prompt decarboxylation process to form a triplet protonated biradical carbanion species. For solvents with moderate higher water concentrations (such as between 50% and 90% water by volume), the hydrogen abstraction and decarboxylation processes are two competitive pathways with different rate constants. The triplet state of ketoprofen will simultaneously produce a ketyl radical species and a triplet protonated biradical carbanion species with the amount of each species dependent on the water concentration. the Owner Societies.
- Li, Ming-De,Du, Yong,Chuang, Yung Ping,Xue, Jiadan,Phillips, David Lee
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- Local Light-Controlled Generation of Calcium Carbonate and Barium Carbonate Biomorphs via Photochemical Stimulation
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Photochemical activation is proposed as a general method for controlling the crystallization of sparingly soluble carbonates in space and time. The photogeneration of carbonate in an alkaline environment is achieved upon photo-decarboxylation of an organic precursor by using a conventional 365 nm UV LED. Local irradiation was conducted focusing the LED light on a 300 μm radius spot on a closed glass crystallization cell. The precursor solution was optimized to avoid the precipitation of the photoreaction organic byproducts and prevent photo-induced pH changes to achieve the formation of calcium carbonate only in the corresponding irradiated area. The crystallization was monitored in real-time by time-lapse imaging. The method is also shown to work in gels. Similarly, it was also shown to photo-activate locally the formation of barium carbonate biomorphs. In the last case, the morphology of these biomimetic structures was tuned by changing the irradiation intensity.
- Menichetti, Arianna,Mavridi-Printezi, Alexandra,Falini, Giuseppe,Besirske, Patricia,García-Ruiz, Juan Manuel,C?lfen, Helmut,Montalti, Marco
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- Increasing the life expectancy of carbanions by zeolite inclusion
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Carbanions have been detected for the first time in zeolite cavities where their lifetime is more than ten times longer than in solution; included carbanions show Grignard-like behaviour.
- Chretien, Michelle N.,Cosa, Gonzalo,Garcia, Hermenegildo,Scaiano
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- Influence of solvent polarity and base concentration on the photochemistry of ketoprofen: Independent singlet and triplet pathways
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The photochemistry of ketoprofen in aqueous solutions is strongly influenced by its acid-base chemistry. While the acid form of ketoprofen behaves as a typical benzophenone chromophore, the ketoprofen carboxylate undergoes efficient photodecarboxylation i
- Cosa, Gonzalo,Martinez, Lydia J.,Scaiano
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- Photochemical reaction of 2-(3-benzoylphenyl)propionic acid (ketoprofen) with basic amino acids and dipeptides
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Photoreaction of 2-(3-benzoylphenyl)propionic acid (ketoprofen, KP) with basic amino acids (histidine, lysine, and arginine) and dipeptides (carnosine and anserine) including a histidine moiety in phosphate buffer solution (pH 7.4) has been investigated w
- Suzuki, Tadashi,Shinoda, Mio,Osanai, Yohei,Isozaki, Tasuku
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- Water- and acid-mediated excited-state intramolecular proton transfer and decarboxylation reactions of ketoprofen in water-rich and acidic aqueous solutions
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We present an investigation of the decarboxylation reaction of ketoprofen (KP) induced by triplet excited-state intramolecular proton transfer in water-rich and acidic solutions. Nanosecond time-resolved resonance Raman spectroscopy results show that the
- Li, Ming-De,Yeung, Chi Shun,Guan, Xiangguo,Ma, Jiani,Li, Wen,Ma, Chensheng,Phillips, David Lee
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- A remarkably long-lived benzyl carbanion
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(Equation presented) The photochemistry of ketoprofen, a widely used nonsteroidal antiinflammatory drug (NSAID) has been the subject of several studies as a result of its known phototoxicity. Photolysis of ketoprofen leads to 3-ethylbenzophenone, a proces
- Laferriere, Marie,Sanrame, Carlos N.,Scaiano
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- Diastereoselectivity and site dependency in the photochemistry of ketoprofen in the bovine serum albumin matrix
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The photodegradation of the S(+)- and R(-)-ketoprofen (KP) enantiomers in the bovine serum albumin matrix was studied by steady-state photolysis with the use of λirr 320 nm and transient absorption spectroscopy with λexc = 355 nm, at 1/1 and 2/1 KP/BSA molar ratios. R(-)-KP was found to be more labile than S(+). Triplet ketoprofen species were evidenced with lifetimes of 400 ns for S(+) and 600 ns for R(-)-KP. Further longer-lived transients with lifetimes of 2.6 and 6.0 μs for S(+) and R(-), respectively, were detected. On the basis of the binding constants of the drug enantiomers to the two main binding sites of the protein, obtained from circular dichroism experiments, the individual disappearance quantum yields of the 1:1 and 2:1 diastereomeric KP:BSA complexes could be estimated. The photoreactivity in the BSA matrix was rationalized on the basis of diastereoselective photodecarboxylation in the two main protein sites.
- Monti, Sandra,Manet, Ilse,Manoli, Francesco,Morrone, Raffaele,Nicolosi, Giovanni,Sortino, Salvatore
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- Triplet Photoreactivity of the Diaryl Ketone Tiaprofenic Acid and Its Decarboxylated Photoproduct. Photobiological Implications
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The 2-benzoylthiophene chromophore of the photosensitizing drug tiaprofenic acid and of its decarboxylated derivative is characterized by a unusually high energy gap between the T1 (π,π*) and T2 (n,π*) excited states, which makes thi
- Encinas, Susana,Miranda, Miguel A.,Marconi, Giancarlo,Monti, Sandra
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- Photochemistry of 2-(3-benzoylphenyl)propionic acid (ketoprofen): Part 1. A picosecond and nanosecond time resolved study in aqueous solution
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The photochemistry of ketoprofen (KPF), 2-(3-benzoylphenyl)propionic acid, has been studied in aqueous solutions by time resolved (picosecond and nanosecond) spectroscopic techniques. Excited-state calculations were performed. The overall reactivity of th
- Monti, Sandra,Sortino, Salvatore,De Guidi, Guido,Marconi, Giancarlo
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- Photoinduced Proton-Transfer Polymerization: A Practical Synthetic Tool for Soft Lithography Applications
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Proton-transfer photopolymerization through the thiol-epoxy click reaction is shown to be a versatile new method for the fabrication of micro- A nd nanosized polymeric patterns. In this approach, complexation of a guanidine base, diazabicycloundecene (DBU), with benzoylphenylpropionic acid (ketoprofen) generates a photolabile salt. Under illumination at a wavelength of 365 nm, the salt undergoes a photodecarboxylation reaction to release DBU as a base. The base-catalyzed ring opening reaction then creates cross-linked poly(β-hydroxyl thio-ether) patterns. The surface chemistry of these patterns can be altered through alkylation of the thio-ether linkages. For example, a reaction with bromoacetic acid produces a hitherto unknown sulfonium/carboxylate-based zwitterionic motif that endows antibiofouling capacity to the micropatterns.
- Khan, Anzar,Yeo, Hyunki
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p. 3479 - 3488
(2020/02/27)
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- PH Dependent Photodeprotection of Formaldehyde: Homolytic C-C Scission in Acidic Aqueous Solution versus Heterolytic C-C Scission in Basic Aqueous Solution
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The photodeprotection of formaldehyde was investigated for 3-(1-hydroxypropan-2-yl)benzophenone (3-HPBP) with ultrafast time-resolved spectroscopy. The femtosecond transient absorption results indicated the singlet excited state of 3-HPBP transformed efficiently into its triplet state by a fast intersystem crossing. In acidic (pH = 0) and basic (pH = 12.5) aqueous solutions, the triplet intermediate was a key precursor for the deprotection of formaldehyde via two different pathways. However, little photodeprotection was observed in neutral (pH = 7) aqueous solution where the triplet intermediate appeared to undergo a proton coupled electron transfer process to form a ketyl radical transient. The important benzylic biradical intermediates seen in the acidic and basic aqueous solutions were identified by time-resolved resonance Raman spectra whose vibrational frequency patterns were consistent with DFT calculation results for the benzylic biradical intermediate. The results here indicate that the β-carbon alcohol group of the triplet state 3-HPBP is deprotonated in basic aqueous solutions and this leads to a heterolytic C-C bond cleavage to deprotect formaldehyde and produce the benzylic carbanion triplet state species, whereas protonation of the carbonyl moiety of the triplet state 3-HPBP leads to direct generation of a benzylic biradical intermediate and the deprotection of formaldehyde in acidic aqueous solutions via a homolytic C-C bond cleavage.
- Liu, Mingyue,Tang, Wenjian,Li, Ming-De,Phillips, David Lee
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supporting information
p. 3425 - 3431
(2017/04/13)
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- Ketoprofen as a photoinitiator for anionic polymerization
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A new photoinitiating system for anionic polymerization of acrylates based on the efficient photodecarboxylation of Ketoprofen (1) and the related derivatives 3 and 4 that generate the corresponding carbanion intermediates is presented. Carbanion intermediates are confirmed by deuterium incorporation in the trapped Michael adducts and by spectroscopic detection using laser flash photolysis (LFP). This novel anionic initiating system features excitation in the near UV and visible regions, potential characteristics of photocontrolled living polymerization, and metal-free photoinitiators generated from photoexcitation, different from typical anionic polymerization where the polymerizations are initiated by heat and strong base containing alkali metals.
- Wang, Yu-Hsuan,Wan, Peter
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p. 1120 - 1126
(2015/06/17)
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- Erbium trifluoromethanesulfonate catalyzed Friedel-Crafts acylation using aromatic carboxylic acids as acylating agents under monomode-microwave irradiation
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Erbium trifluoromethanesulfonate is found to be a good catalyst for the Friedel-Crafts acylation of arenes containing electron-donating substituents using aromatic carboxylic acids as the acylating agents under microwave irradiation. An effective, rapid and waste-free method allows the preparation of a wide range of aryl ketones in good yields and in short reaction times with minimum amounts of waste.
- Tran, Phuong Hoang,Hansen, Poul Erik,Nguyen, Hai Truong,Le, Thach Ngoc
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p. 612 - 618
(2015/02/19)
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- Simultaneous identification of Fenton degradation by-products of diclofenac, ibuprofen and ketoprofen in aquatic media by comprehensive two-dimensional gas chromatography coupled with mass spectrometry
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Diclofenac, ibuprofen and ketoprofen are anti-inflammatory drugs intensively used both in human and animal treatment. Due to their high stability these compounds are partially removed by wastewater treatment plants and from this reason the development of some alternative treatments such as advanced oxidative processes are necessary. The main problems in the optimization of an advanced oxidative process rise from the difficulties which appear in the identification of degradation by-products necessary for the establishment of degradation pathway. In this paper a developed method for the simultaneous identification of Fenton degradation by-products of the three above mentioned pharmaceuticals is presented. The obtained results show the comprehensive two-dimensional gas chromatography coupled with mass spectrometry as a proper method for the analysis of the complex mixture of compounds resulted from the Fenton degradation process. Moreover, some compounds never mentioned in the scientific literature were identified. (Chemical Equation Presented).
- Beldean-Galea, Mihail Simion,Coman, Virginia,Copaciu, Florina,Thiébaut, Didier,Vial, Jér?me
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p. 1021 - 1027
(2015/07/15)
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- Improvement of the Friedel-Crafts benzoylation by using bismuth trifluoromethanesulfonate in 1-butyl-3-methylimidazolium trifluoromethanesulfonate ionic liquid under microwave irradiation
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Bismuth trifluoromethanesulfonate (bismuth triflate) catalyzed the Friedel-Crafts benzoylation of activated aromatic compounds when dissolved in 1-butyl-3-methylimidazolium trifluoromethanesulfonate ([BMIM]OTf) ionic liquid. Immobilization of bismuth triflate (5 mol %) in [BMIM]OTf allowed the synthesis of aryl ketones in good to excellent yields with short reaction times under microwave irradiation. This catalytic system was easily recovered and reused several times without any significant loss of the activity.
- Hoangtran, Phuong,Bichle Do, Ngoc,Ngocle, Thach
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p. 205 - 208
(2014/01/06)
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- Microwave-assisted facile and rapid friedel-crafts benzoylation of arenes catalyzed by bismuth trifluoromethanesulfonate
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The catalytic activity of metal triflates was investigated in Friedel-Crafts benzoylation under microwave irradiation. Friedel-Crafts benzoylation with benzoyl chloride of a variety of arenes containing electron-rich and electron-poor rings using bismuth triflate under microwave irradiation is described. This method allows the preparation of aryl ketones under solventless conditions in good to excellent yields and short reaction time. Bismuth triflate was easily recovered and reused five times without significant loss of the catalytic activity.
- Tran, Phuong Hoang,Hansen, Poul Erik,Pham, Thuy Thanh,Huynh, Vy Thanh,Huynh, Vy Hieu,Thi Tran, Thao Du,Huynh, Thanh Van,Le, Thach Ngoc
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p. 2921 - 2929
(2014/10/15)
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- Application to photoreactive materials of photochemical generation of superbases with high efficiency based on photodecarboxylation reactions
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A thin film of polystyrene containing 4c was spin-coated on a CaF2 plate and irradiated with 365 nm light. The absorption band arising from the carboxylate of 4c at 1372 cm-1 in the FTIR spectrum decreased after UV irradiation. Radical UV curing materials that are well established in the marketplace have drawbacks because of high volume shrinkage and oxygen inhibition. The anionically cured film showed high transparency and no volume shrinkage, in contrast to a conventional radical UV curing system, which showed large volume shrinkage. This is probably due to relatively low quantum yields for photobase generation and weaker basicity of photo-generated bases, leading to low photosensitivity of photoreactive materials sensitized with photobase generators. Furthermore, many of the photobase generators reported are generally prepared via several synthetic steps.
- Arimitsu, Koji,Endo, Ryosuke
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p. 4461 - 4463
(2014/01/06)
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- Application of complementary mass spectrometric techniques to the identification of ketoprofen phototransformation products
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Ketoprofen (KP) is a nonsteroidal anti-inflammatory drug, which during UV irradiation rapidly transforms into benzophenone derivatives. Such transformation products may occur after topical application of KP, which is then exposed to sunlight resulting in a photo-allergic reaction. These reactions are mediated by the benzophenone moiety independently of the amount of allergen. The same reactions will also occur during wastewater or drinking water treatment albeit their effect in the aqueous environment is yet to be ascertained. In addition, only a few such transformation products have been recognised. To enable the detection and structural elucidation of the widest range of KP transformation products, this study applies complementary chromatographic and mass spectrometric techniques including gas chromatography coupled to single quadrupole or ion trap mass spectrometry and liquid chromatography hyphenated with quadrupole-time-of-flight mass spectrometry. Based on structural information gained in tandem and multiple MS experiments, and on highly accurate molecular mass measurements, chemical structures of 22 transformation products are proposed and used to construct an overall breakdown pathway. Among the identified transformation products all but two compounds retained the benzophenone moietya€"a result, which raises important issues concerning the possible toxic synergistic effects of KP and its transformation products. These findings trigger further research into water treatment technologies that would limit their entrance into environmental or drinking waters. Copyright
- Kosjek, Tina,Perko, Silva,Heath, Ester,Kralj, Bogdan,Zigon, Dusan
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experimental part
p. 391 - 401
(2011/11/12)
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- Formal intramolecular photoredox chemistry of meta-substituted benzophenones
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(Chemical Equation Presented) Photolysis of 3-(hydroxymethyl)benzophenone (1) in aqueous solution (pH -4 M) conditions. Evidence suggests that the highly efficient (Φ ~ 0.6) reaction involves a unimolecular mechanism and an overall formal intramolecular photoredox process, which requires electronic communication between the 1,3-positions of the benzene ring, an unprecedented example of the photochemical meta effect. The photoredox reaction was not observed in organic solvents, where only photoreduction of the benzophenone moiety was observed.
- Mitchell, Devin,Lukeman, Matthew,Lehnherr, Dan,Wan, Peter
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p. 3387 - 3389
(2007/10/03)
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- Perfluoroalkanesulfonic acid catalyzed acylations of alkylbenzenes: Synthesis of alkylanthraquinones
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The acylation of alkylbenzenes 1 with benzoyl chloride 2 and catalytic amounts of perfluorobutanesulfonic acid affords the corresponding 2-, 3-, and 4-alkylbenzophenones 3 with unusually high amounts of ortho products. Surprisingly, even tert-butylbenzene reacts under these reaction conditions without any acid catalyzed dealkylation. The yield of benzoylation of p-xylene 4 with benzoic acid in the presence of 5 mol% C4F9SO3H to give 2,5-dimethylbenzophenone 5 could significantly be improved from 14% to 90% by continuous removal of water formed during the acylation. Also in the preparation of alkylanthraquinones 7 by reaction of alkylbenzenes with phthalic anhydride, water removal is the decisive factor to obtain satisfactory yields for the second acylation, allowing to cyclize 6 with catalytic amounts (10 mol%) of CF3SO3H in organic solvents to the corresponding alkylanthraquinones 7.
- Effenberger,Buckel,Maier,Schmider
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p. 1427 - 1430
(2007/10/03)
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- Photodecarboxylation of ketoprofen in aqueous solution. A time-resolved laser-induced optoacoustic study
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The photodecarboxylation reaction of 2-(3-benzoylphenyl)propionate (ketoprofen anion, KP-) was studied in water and in 0.1 M phosphate buffer solutions in the pH range 5.7-11.0 by laser-induced optoacoustic spectroscopy (LIOAS, T range 9.5-31.6
- Borsarelli, Claudio D.,Braslavsky, Silvia E.,Sortino, Salvatore,Marconi, Giancarlo,Monti, Sandra
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p. 163 - 171
(2007/10/03)
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- Transient intermediates in the laser flash photolysis of ketoprofen in aqueous solutions: Unusual photochemistry for the benzophenone chromophore
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The transient intermediates the nanosecond laser flash photolysis of ketoprofen, an arylpropionic acid, show the formation of a carbanion in aqueous solutions at pH 7.1. This carbanion incorporates spectroscopic properties from both a ketyl radical anion and a benzylic radical. The ketoprofen carboxylate undergoes biphotonic photoionization, a process that contributes less than 10% to its photodecomposition- and leads to a benzylic-type radical after decarboxylation with a rate constant ≤1 x 107 s-1. On the other hand, the carbanion forms monophotonically and the unsuccessful attempts to sensitize the formation of the ketoprofen triplet excited state in aqueous solutions suggest that the carbanion precursor is either an excited singlet state or an extremely short-lived triplet. In organic solvents of lower polarity, the excited triplet state is readily detectable.
- Martínez,Scaiano
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p. 11066 - 11070
(2007/10/03)
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- Photochemical and photobiological properties of ketoprofen associated with the benzophenone chromophore.
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Irradiation of ketoprofen in neutral aqueous medium gave rise to 3-ethylbenzophenone as the major photoproduct. Its formation is justified via protonation of a benzylic carbanion or hydrogen abstraction by a benzylic radical. Minor amounts of eight additional compounds were isolated. Four of them are derived from the benzylic radical: 3-(1-hydroperoxyethyl)benzophenone, 3-(1-hydroxyethyl)benzophenone, 3-acetylbenzophenone and 2,3-bis-(3-benzoylphenyl)butane. The other four products involve initial hydrogen abstraction by the excited benzophenone chromophore of ketoprofen: 1,2-bis-(3-ethylphenyl)-1,2-diphenyl-1,2-ethanediol, 2-(3-benzoylphenyl)-1-(3-ethylphenyl)-1-phenylpropan-1-ol, alpha-(3-ethylphenyl)phenylmethanol, 1,2-bis-[3-(2-hydroxycarbonylethyl) phenyl]-1,2-diphenyl-1,2-ethanediol. The latter process was found to mediate the photoperoxidation of linoleic acid through a type I mechanism, as evidenced by the inhibition produced by the radical scavengers butylated hydroxyanisole and reduced glutathione. The major photoproduct, which contains the benzophenone moiety but lacks the propionic acid side chain, also photosensitized linoleic acid peroxidation. Because lipid peroxidation is indicative of cell membrane lysis, the above findings are highly relevant to explain the photobiological properties of ketoprofen.
- Bosca,Miranda,Carganico,Mauleon
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- Friedel-Crafts Alkylation of Benzenes Substituted with Meta-Directing Groups
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In protonic acids, benzaldehyde, acetophenone, benzophenone, and ethyl benzoate were ring-alkylated by alcohols.Benzonitrile was N-alkylated rather than ring-alkylated.Ethyl n-propyl, isopropyl, and n-butyl alcohol were effective alkylating agents, wherea
- Shen, Yu-Sheng,Liu, Hong-Xia,Wu, Ming,Du, Wu-Qin,Chen, Yi-Qiu et al
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p. 7160 - 7162
(2007/10/02)
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- Process for preparing 3-ethylbenzophenone
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3-Ethylbenzophenone is prepared by oxidizing a by-product heavy oil fraction produced in the production of ethylbenzene using ZSM-5 type synthetic zeolite catalyst, without splitting carbon-to-carbon bonds. 3-Ethylbenzophenone is a starting material for synthesis of medicines, etc.
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- UNE VOIE ORIGINALE ET SELECTIVE DE FONCTIONNALISATION EN POSITION META DU FLUORO- ET DE L'ETHYLBENZENE
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An original and regioselective method for the meta functionalisation of fluoro- and ethylbenze is reported.This process involves a 2,5-disilylation of these subtrates using trimethylchlorosilane in the presence of lithium in THF as the solvent.After aromatisation, monodesilylation in position 2- and electrophilic substitution of the trimethylsilyl group in position 5-, meta acetyl-, senecioyl-, benzoyl-, and iodofluorobenzenes and ethylbenzenes as well as the sodium salts of metafluoro or meta ethylbenzenesulfonic acid and 3-aminosulfonylfluorobenzene were obtained in good yields. pair of diastereomeric triamines 15 and 16.A tricyclic diazasystem 19 was formed from the reaction of cyanide with the carbamoylated chloroenamine 18.Monochloroenamine 10a and dichloroenamine 12a showed a significant mutagenic behaviour in the Ames test.
- Bennetau, Bernhard,Krempp, Michele,Dunogues, Jacques,Ratton, Serge
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p. 8131 - 8142
(2007/10/02)
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- 1,1-(3-ethylphenyl)phenylethylene and method for preparing it
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The present invention is concerned with a novel intermediate 1,1-(3-ethylphenyl)phenylethylene represented by the formula (I) and its manufacturing method, and according to the present invention, Ketoprofen can be synthesized at a low cost and in a high y
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