- Photocatalytically green synthesis of H2O2 using 2-ethyl-9,10-anthraquinone as an electron condenser
-
A high level (～9 mM) of hydrogen peroxide is photocatalytically synthesized by using O2 as an oxidant and 2-ethyl-9,10-anthraquinone (EAQ) as an electron condenser. The photo-catalytic efficiency of the EAQ-assisted H2O2 production is ca. 10-fold higher than that of H2 generation with Pt/P25. This journal is
- Zhang, Dandan,Xu, Gangqiang,Chen, Tao,Chen, Feng
-
-
Read Online
- Hydrogen peroxide synthesis by direct photoreduction of 2-ethylanthraquinone in aerated solutions
-
A new synthesis method of hydrogen peroxide was investigated by the photoreduction of 2-ethylanthraquinone (AQ) in water-insoluble organic solvents. Through optimizing the photoreduction condition including solvent, atmosphere and irradiated time, the photolysis system of 1,3,5-trimethylbenzene/trioctyl phosphate (3:1) solvent mixture under oxygen atmosphere was found to give a high yield of hydrogen peroxide. Furthermore, the formation mechanism of hydrogen peroxide was proposed, i.e. photoreduction and subsequent oxidation of AQ. The photoreduction of 2-ethylanthraquinone undergoes the hydrogen abstraction from solvent to form the anthrahydroquinone, which is subsequently oxidized by oxygen to give hydrogen peroxide.
- Ren, Ming-Guang,Mao, Mao,Duan, Xue-You,Song, Qin-Hua
-
-
Read Online
- Engineering the porosity and acidity of H-Beta zeolite by dealumination for the production of 2-ethylanthraquinone via 2-(4′-ethylbenzoyl)benzoic acid dehydration
-
Environmentally-friendly zeolites have been used commercially to replace concentrated sulfuric acid and oleum in the alkylation reactions and dehydration of alcohols. However, moderate activity, associated with access and diffusion limitations, low intramolecular dehydration selectivity, associated with unsatisfactory acidity, and unknown reusability have hampered their industrial implementation in the dehydration of bulky 2-(4′-ethylbenzoyl)benzoic acid (E-BBA) to 2-ethylanthraquinone (2-EAQ). Herein, we have discovered that after being treated with mild HNO3, nano-sized H-Beta zeolite showed outstanding catalytic activity, selectivity and reusability, compared with a commercial oleum catalyst. A number of techniques, such as XRD, XPS, XRF, 29Si MAS NMR, 27Al MQ MAS NMR, FTIR, NH3-TPD, argon physisorption and HR-TEM, have been employed to decouple the interdependence between acidity, porosity and catalytic performance. It was found that mild HNO3 treatment could clean out the extra-framework aluminium deposits and selectively extract the aluminium species on the outer surface of Beta zeolites, which strengthened the acidity of the Br?nsted acid sites (Si(OH)Al) inside the H-Beta micropores, thus increasing the possibility of intramolecular dehydration of E-BBA. Moreover, this mild HNO3 treatment also dredged the network of intercrystalline mesopores, alleviating the diffusion constraints. Therefore, through the dual adjustment of acidity and porosity, dealuminated H-Beta zeolite has a promising future in the green synthesis of 2-EAQ.
- Liu,He,Liu,Wang,Xin,Guo
-
-
Read Online
- Role of phosphorus in the formation of selective palladium catalysts for hydrogenation of alkylanthraquinones
-
Effective Pd-P catalysts for the hydrogenation of 2-ethyl-9,10-anthraquinone in a toluene/1-octanol medium were obtained. Phosphorus modification increases the selectivity of the active quinones from 69% to 93%–97%, and the deposition of Pd-P catalyst particles on a carbon support increases their activity fivefold due to increased dispersion without a decrease in selectivity to the target product. Using energy dispersive X-ray spectroscopy, X-ray powder diffraction, high-resolution transmission electron microscopy and X-ray photoelectron spectroscopy, the composition, size and state of the surface layers of Pd-P catalysts were determined. Surface enrichment by the electron-deficient palladium and structural disorder of Pd-P catalyst particles were shown to account for the increase in selectivity to active quinones during hydrogen peroxide production by the anthraquinone method.
- Belykh, Lyudmila B.,Skripov, Nikita I.,Sterenchuk, Tatyana P.,Akimov, Vladlen V.,Tauson, Vladimir L.,Savanovich, Tatyana A.,Schmidt, Fedor K.
-
-
Read Online
- Friedel - gram acylating reaction method based on phthalic anhydride and aromatic alkyl compound
-
A part of a substituted alkylbenzene is used as a solvent and a reaction raw material for - gram acylating reaction, a part of a substituted alkylbenzene is dissolved in a reaction raw material phthalic anhydride and a chloroaluminate ionic liquid catalyst, and a residual part of a substituted alkylbenzene is added dropwise - to obtain - (2 - 4' - alkylbenzoyl) benzoic acid intermediate. 2 -position positioning selectivity of the method is higher, and the reaction production cost is low.
- -
-
-
- PROCESS FOR PRODUCING SUBSTITUTED ANTHRAQUINONE
-
A process for manufacturing a compound of formula (II), said process comprising a step of reacting a compound of formula (I) in the presence of a zeolite catalyst and a solvent, (I), (II) wherein R1, R2, R3, R4, R5, R6, R7 and R8 are independently H, halo, C1-C12 alkyl, C1-C12 alkyloxy, C2-C12 alkenyl, C2-C12 alkenyloxy, C2-C12 alkynyl, C2-C12 alkynyloxy, C3-C8 cycloalkyl, C3-C8 cycloalkyloxy, C6-C10 aryl, C6-C10 aryloxy, C7-C10 aralkyl, C7-C10 alkylaryl or C4-C7 heteroaryl; and wherein the solvent is a halogen substituted aromatic compound.
- -
-
Page/Page column 7-8; 10-11
(2020/06/10)
-
- Green synthesis method for preparing 2-alkylanthraquinone from phthalic anhydride in one step
-
The invention relates to the technical field of green synthesis of organic matters. The invention relates to a synthetic method, in particular to a green synthetic method for preparing 2-alkylanthraquinone from phthalic anhydride in one step. According to the method, phthalic anhydride and alkylbenzene are used as raw materials, difunctional sulfonic acid type solid acid based on an HZSM-5 molecular sieve is used as a catalyst, phthalic anhydride and alkylbenzene are catalyzed to be subjected to a Friedel-Crafts acylation reaction and a dehydration cyclization reaction at the same time under the action of the catalyst, so that the 2-alkyl anthraquinone is prepared in one step, wherein the bifunctional sulfonic acid type solid acid based on the HZSM-5 molecular sieve is a sulfonic acid typeHZSM-5 molecular sieve obtained by carrying out sulfonation treatment on the HZSM-5 molecular sieve. According to the synthesis method of the 2-alkyl anthraquinone, the bifunctional (with strong Bronsted acidity and Lewis acidity) sulfonic acid type solid acid based on the HZSM-5 molecular sieve is used as the catalyst to replace AlCl3 and fuming sulfuric acid, so that generation of a large amount of waste residues, waste gas and wastewater is avoided, and green production is realized.
- -
-
Paragraph 0036-0037; 0040-0041
(2020/06/16)
-
- Method for synthesizing 2-alkylanthraquinone
-
The invention discloses a method for synthesizing 2-alkylanthraquinone. The method comprises the following steps: preparing a tert-butylanthraquinone intermediate BE acid from phthalic anhydride and alkylbenzene in the presence of a Lewis acid, carrying out dehydration ring closure by adopting a combined dehydrating agent composed of polyphosphoric acid and phosphorus pentoxide, pouring the obtained solution into ice water after the end of the ring closure I order to dilute the polyphosphoric acid to a certain concentration, adding xylene for extraction after water precipitation is finished, washing and concentrating the obtained extract to obtain a brown yellow block solid, and recrystallizing the solid to obtain the 2-alkylanthraquinone. The method of the invention the advantages of avoiding of using of fuming sulfuric acid and production of a large amount of dilute sulfuric acid in the phthalic anhydride method production process of anthraquinone, easily available raw materials, mild reaction conditions, easiness in application in industrial production, realization of continuous using of the byproduct phosphoric acid as the dehydrating agent after addition of phosphorus pentoxide, and good environmental protection meaning.
- -
-
-
- Method for driving molecular oxygen to selectively oxidize 9,10-dihydroanthracene and quantitatively convert 9,10-dihydroanthracene into anthraquinone by visible light
-
The invention relates to the technical field of photooxidation synthesis, and discloses a simple, convenient and practical visible light synthesis method for quantitatively converting 9, 10-dihydroanthracene into anthraquinone based on molecular oxygen selective oxidation. Under a condition of normal temperature, normal pressure, pure oxygen atmosphere and no catalysts and additives, the synthesismethod can realize 100% raw material conversion and provide a anthraquinone yield of 99.3%, and 86.4% of anthraquinone yield can be obtained even in an air atmosphere. Moreover, the synthesis methodalso shows a good effect on photooxidation of other compounds with structures similar to the structure of 9, 10-dihydroanthracene, and the synthesis method is indicated to have relatively wide applicability. The visible light synthesis method provided by the invention provides a very good example for participation of active O2 of a substrate in selective oxidation, and accords with the concept ofgreen chemistry.
- -
-
Paragraph 0017-0026
(2020/01/03)
-
- Preparation method of 2-ethylanthracene
-
The invention discloses a preparation method of 2-ethylanthracene. The preparation method comprises the following steps: firstly, 2-(4-ethylbenzoyl) benzoic acid is prepared; then, 2-(4-ethylbenzoyl)benzoic acid is subjected to a reaction with concentrated sulfuric acid in a tubular reactor comprising a T-shaped mixer, a reactor A, a Y-shaped mixer, a reactor B and a separator, and 2-ethyl anthraquinone is prepared; finally, a strong ammonia solution as a reaction medium, crystalline copper sulfate as a catalyst, zinc powder as a reducing agent, and 2-ethyl anthraquinone as a raw material aresubjected to reflux reaction at 70-80 DEG C for 1-3 h, a reaction product is cooled to the room temperature after the reaction and is subjected to silica-gel column chromatography, and 2-ethylanthracene is prepared. The disclosed method is simple to operate, and the yield of the target product is high.
- -
-
-
- Synthetic method of 2-alkylanthraquinone
-
The invention provides a synthetic method of 2-alkylanthraquinone, comprising the steps of subjecting the raw material 2-(4'-alkylbenzoyl)benzoic acid to acryl halogenation under the action of an acryl halogenation reagent to obtain an intermediate; subjecting the intermediate of step I to intracellular Friedel-Crafts alkylation under the catalysis of Lewis acid; dissolving the product of step IIwith a solvent, filtering, and purifying. The synthetic method of 2-alkylanthraquinone has high reaction speed, high conversion rate and few side reactions, the reagent for reaction is low in price and easy to obtain, post-reaction treatment is simple, and few three wastes are produced.
- -
-
Paragraph 0027-0029; 0030-0032; 0036-0041
(2018/05/16)
-
- Method for preparing 2-alkylanthraquinone with microchannel continuous reactor
-
The invention belongs to the field of chemical synthesis, and particularly relates to a method for preparing 2-alkylanthraquinone with a microchannel continuous reactor. The synthesis is carried out in a microchannel reactor, and the method comprises the following steps: (1) catalyzing phthalic anhydride and alkylbenzene by using AlCl3 as a catalyst, and performing a Friedel-Crafts acylation reaction to generate 2-(4-alkyl benzoyl) benzoic acid; and (2) continuously reacting the 2-(4-alkyl benzoyl) benzoic acid with concentrated sulfuric acid through a mixer I, a reactor I, a mixer II, a reactor II and a separation unit of the microchannel reactor to generate the 2-alkylanthraquinone in a closed loop mode. Compared with a traditional intermittent reaction, the microchannel reaction adoptedin the method has the advantages of relatively good microchannel airtightness, high safety, little pollution and simple operation; the product has a yield increased by 5-10 percent in comparison withthat of an existing production process, and has high quality.
- -
-
Paragraph 0027-0028
(2018/04/26)
-
- Method for synthesizing 2-ethylanthraquinone by taking heteropoly acid intercalated hydrotalcite as catalyst
-
The invention discloses a method for synthesizing 2-ethylanthraquinone by taking heteropoly acid intercalated hydrotalcite as a catalyst. According to the method, the 2-ethylanthraquinone is producedin a closed-loop manner through enabling 2-(4'-ethylbenzoyl)benzoic acid, which serves as a raw material, to react for 1.0 to 4.0 hours at the temperature of 180 DEG C to 250 DEG C in the presence ofthe heteropoly acid intercalated trihydroxymethyl hydrotalcite, which serves as the catalyst. The adopted heteropoly acid intercalated trihydroxymethyl hydrotalcite catalyst is prepared through takingtrihydroxymethyl modified magnalium hydrotalcite as a precursor and carrying out ion exchange with heteropoly acid. According to the method, the defect in the prior art that a large volume of unmanageable waste acid is generated due to fuming sulfuric acid is avoided.
- -
-
Paragraph 0024; 0025; 0028; 0032; 0035
(2018/07/15)
-
- Method for preparing 2-alkyl anthraquinone by taking solid super acids as catalysts
-
The invention provides a method for preparing 2-alkyl anthraquinone by taking solid super acids as catalysts. The 2-alkyl anthraquinone (alkyl is straight or branched alkyl with the number of carbon atoms of 1-6) is obtained by adopting the solid super acids like perfluorinated sulfonic acid resin and heteropoly acid as the catalysts, taking 2-(4'-alkyl benzoyl) benzoic acid as a raw material andperforming acylated dewatering closed loop through Friedel-Crafts reaction. The method provided by the invention is characterized in that traditional smoking sulfuric acid catalysts are replaced by the solid super acids, so that the environment is friendly, and no waste acid is discharged; the operation process is simple, and the solid catalysts are easy to recover; therefore, the method is a green pollution-free new process.
- -
-
Paragraph 0030-0037
(2020/03/28)
-
- The Effect of Particle Size and the Modifier on the Properties of Palladium Catalysts in the Synthesis of Hydrogen Peroxide by the Anthraquinone Method
-
The effect of the composition of the catalytic system and the size of particles on the properties of palladium catalysts in 2-ethyl-9,10-anthraquinone hydrogenation was studied. It was shown that, depending on the nature of a reducing agent (H2, AlEt3), palladium species formed in the absence of a modifying agent catalyze various side processes to a substantial extent together with 2-ethyl-9,10-anthraquinone hydrogenation: mostly hydrogenolysis (in the case of H2 as a reducing agent) and hydrogenation of aromatic rings in 2-ethyl-9,10-anthrahydroquinone (in the case of AlEt3 as a reducing agent). Elementary phosphorus was found to have a promoting effect on the selectivity of palladium catalysts in the synthesis of hydrogen peroxide by the anthraquinone method. The main factors that make it possible to control the selectivity of palladium catalysts were discussed.
- Belykh, L. B.,Gvozdovskaya, K. L.,Sanzhieva, S. B.,Schmidt, F. K.,Skripov, N. I.,Sterenchuk, T. P.
-
p. 585 - 592
(2018/10/02)
-
- A 2 - alkyl anthraquinone synthetic method (by machine translation)
-
The invention provides a 2 - alkyl anthraquinone synthetic method, the 2 - alkyl anthraquinone synthetic method comprises the following steps: the 2 - (4' - alkyl benzoyl) benzoic acid in the presence of a solvent through the acyl acyl; under the action of the promoter, using anhydrous aluminum ring to carry out the dehydrochlorination; reactant through hydrolysis, liquid separation, pressure reducing desolventizing, drying, to obtain 2 - alkyl anthraquinone. The beneficial effect of the present invention is: not the use of fuming sulfuric acid, mild reaction conditions, acid-free, simple process operation, the product quality is stable, and the yield of the product than the existing production process to improve the 5 - 10%. (by machine translation)
- -
-
Paragraph 0052
(2017/05/26)
-
- 2-EAQ (2-ethylanthraquinone) synthesis device and technology
-
The invention discloses a 2-EAQ (2-ethylanthraquinone) synthesis device and technology. The technical scheme is characterized in that the 2-EAQ synthesis device comprises a tubular reactor, a hydrolysis kettle and a sphere mixer, wherein a feed chute allowing a solid material to be fed is formed in the sphere mixer; a sprinkling nozzle for jetting a fluid material is arranged in the sphere mixer; a feed tube communicated with the sprinkling nozzle is further arranged on the sphere mixer; the sphere mixer is communicated with one end of the tubular reactor, and the other end of the tubular reactor is communicated with the hydrolysis kettle; with the adoption of the sprinkling mode of the sprinkling nozzle, fuming sulphuric acid is added more slowly, so that the temperature in the sphere mixer is prevented from being increased to be too high due to too high mixing speed of the materials during mixing of the materials, the temperature in a mixing process is controlled to be in a safe mixing temperature range of the two materials, and the mixing process is safer and more stable.
- -
-
Paragraph 0038
(2017/06/20)
-
- Enzymatic Cleavage of Aryl Acetates
-
Seven enzymes have been screened for the cleavage of aryl acetates. Phenyl and naphthyl acetates react with lipases and esterases, whereas the sterically demanding anthracene acetate gave a conversion only with porcine liver esterase and esterase 2 from Bacillus subtilis (BS2). These two enzymes have been employed on a preparative (0.5 mmol) scale and afforded cleavage products in 91 and 94 % yields, even for anthracene acetate. Thus, this method is superior to chemical cleavage with catalytic amounts of sodium methoxide (Zemplén conditions), which gave only low conversions. Finally, regioselectivity has been achieved with an anthracene bisacetate, in which an ethyl group controls the cleavage of the first acetate. This indicates that steric interactions play a crucial role in the enzymatic cleavage of aryl acetates, which might be interesting for future applications or the development of enzyme inhibitors.
- Bauch, Marcel,B?ttcher, Dominique,Bornscheuer, Uwe T.,Linker, Torsten
-
p. 2853 - 2857
(2016/09/13)
-
- A silicon modified the alkali escapes H β molecular sieve catalytic ethylbenzene with the reaction one-step process for preparing phthalic anhydride 2-ethyl anthraquinone method
-
The invention relates to a method for preparing 2-ethyl anthraquinone with a one-step method, in particular to a method for preparing the 2-ethyl anthraquinone through a one-step reaction of ethylbenzene and phthalic anhydride under catalysis of an alkali desilication modified Hbeta molecular sieve, and aims to solve technical problems that the production technology is complex, a large amount of acid wastewater is produced, equipment is corroded severely, catalysts cannot be recycled and continuity of the production process cannot be realized due to the fact that two homogeneous catalysts, namely, anhydrous aluminum trichloride and concentrated sulfuric acid, are used respectively when the 2-ethyl anthraquinone is prepared through a two-step reaction of the ethylbenzene and the phthalic anhydride at present. The method comprises steps as follows: the phthalic anhydride and the ethylbenzene are evenly mixed, then the catalyst, namely, the alkali desilication modified Hbeta molecular sieve, is added, the mixture reacts at the reaction temperature of 170-230 DEG C for 1.2-5 h, a solid-liquid mixture is obtained, the solid catalyst, namely, the alkali desilication modified Hbeta molecular sieve, is separated after cooling, and the 2-ethyl anthraquinone is obtained. The method is mild in reaction condition, high in product yield and high in phthalic anhydride conversion rate.
- -
-
Paragraph 0037-0043; 0054; 0061
(2018/02/04)
-
- Direct, copper-catalyzed oxidation of aromatic C-H bonds with hydrogen peroxide under acid-free conditions
-
The direct oxidation of benzene into phenol using hydrogen peroxide has been achieved in the absence of any acid with TpxCu(NCMe) complexes as the catalysts. In the case of anthracenes as the substrates, valuable anthraquinones have been quantitatively obtained in the same manner.
- Conde, Ana,Mar Diaz-Requejo,Perez, Pedro J.
-
supporting information; scheme or table
p. 8154 - 8156
(2011/09/14)
-
- Hypervalent iodine oxidation of phenol derivatives using a catalytic amount of 4-iodophenoxyacetic acid and Oxone as a co-oxidant
-
Reaction of p-substituted phenols 2 with a catalytic amount of 4-iodophenoxyacetic acid (1) and Oxone as a co-oxidant in tetrahydrofuran (THF) or 1,4-dioxane-water gave the corresponding p-quinols 3 in excellent yields. Reaction of p-dialkoxyarenes 4 in 2,2,2-trifluoroethanol- water gave the corresponding p-quinones 5 in excellent yield without purification. These reactions provide efficient and practical methods for the preparation of p-quinols and p-quinones from p-substituted phenols and p-dialkoxyarenes, respectively. This quinone synthesis was applied to synthesis of blattellaquinone (13), the sex pheromone of the German cockroach Blattella germanica.
- Yakura, Takayuki,Omoto, Masanori,Yamauchi,Tian, Yuan,Ozono, Ayaka
-
experimental part
p. 5833 - 5840
(2010/09/11)
-
- A novel process for selective Ruthenium-Catalyzed oxidation of naphthalenes and phenols
-
Arenes are selectively oxidized to the corresponding quinones employing ruthenium(2,2′,6′:2″-terpyridine)(2,6-pyridinedicarboxylate) [Ru(tpy)(pydic] as catalyst and hydrogen peroxide as the terminal oxidant. Applying alkylated naphthalenes and phenols, benzo- and naphthoquinones are obtained in up to 93% yield. The industrially interesting oxidation of 2-methylnaphthalene gave 74% of the corresponding quinones and 60% of menadione (vitamin K3). 2,3,5-Trimethylbenzoquinone which constitutes the key intermediate for vitamin E is obtained in 83% yield.
- Wienhoefer, Gerrit,Schroeder, Kristin,Moeller, Konstanze,Junge, Kathrin,Beller, Matthias
-
scheme or table
p. 1615 - 1620
(2010/09/05)
-
- Nitrous oxide oxidation catalyzed by ruthenium porphyrin complex
-
Dinitrogen oxide was employed as a clean oxidant for various oxidations in the presence of a catalytic amount of dioxoruthenium tetramesitylporphyrin complex (Ru(tmp)(O)2). A variety of olefins, secondary alcohols, and benzyl alcohols were smoothly oxidized to the corresponding epoxides, ketones, and aldehydes in high yields. In the oxidation of 9,10-dihydroanthracene derivatives, the competitive reactions affording anthraquinones and anthracenes could be regulated by the reaction conditions. At a high temperature (200°C), anthraquinones were selectively produced, while the anthracenes were selectively produced by the addition of sulfuric acid.
- Tanaka, Hirotaka,Hashimoto, Kentaro,Suzuki, Kyosuke,Kitaichi, Yasunori,Sato, Mitsuo,Ikeno, Taketo,Yamada, Tohru
-
p. 1905 - 1914
(2007/10/03)
-
- Selective nitrous oxide oxidation for C-H oxidation and aromatization of 9,10-dihydroanthracene derivatives
-
During the nitrous oxide oxidation of 9,10-dihydroanthracene derivatives catalyzed by the ruthenium-porphyrin complexes, anthraquinones were selectively afforded by the C-H oxidation of the benzylic carbon under the appropriate reaction conditions, whereas anthracenes as a result of oxidative aromatization were selectively obtained in the presence of sulfuric acid.
- Hashimoto, Kentaro,Tanaka, Hirotaka,Ikeno, Taketo,Yamada, Tohru
-
p. 582 - 583
(2007/10/03)
-
- Facile Oxidation of Fused 1,4-Dimethoxybenzenes to 1,4-Quinones Using NBS: Fine-Tuned Control over Bromination and Oxidation Reactions
-
(Matrix Presented) Fused 1,4-dimethoxybenzenes could be oxidized to benzoquinones by either direct oxidation or demethylation-oxidation. The oxidative demethylation of 5,8-dimethoxy-2-methylquinoline using 1.1 equiv of NBS in aqueous THF and a catalytic amount of H2SO4 at 20°C for 5 min gave 2-methylquinoline-5,8-dione in 98% yield without bromination. Moreover, we can control either bromination or oxidative demethylation, or both reactions.
- Kim, Dong Wook,Choi, Han Young,Lee, Kee-Jung,Chi, Dae Yoon
-
p. 445 - 447
(2007/10/03)
-
- Novel and efficient synthesis of p-quinones in water via oxidative demethylation of phenol ethers using hypervalent iodine(III) reagents
-
A new method for preparing p-quinone derivatives from phenol ether derivatives in water using the hypervalent iodine(III) reagent, phenyliodine(III) bis(trifluoroacetate) (PIFA) was developed. The present reaction proceeds in good to excellent yields under mild reaction conditions. This oxidation is expected to be environmentally benign since it uses recyclable poly-bis(trifluoroacetoxyiodo)styrene (PBTIS) in water.
- Tohma, Hirofumi,Morioka, Hironori,Harayama, Yu,Hashizume, Miki,Kita, Yasuyuki
-
p. 6899 - 6902
(2007/10/03)
-
- Photophysical and photochemical processes of 2-methyl, 2-ethyl, and 2-tert-butylanthracenes on silica gel. A substituent effect study
-
PAH are organic pollutants formed and released into the environment by the incomplete combustion of fossil fuel, coal, wood, gas, oil, garbage, tobacco, and charbroiled meat. The photophysics and photochemistry of 2-methylanthracene (2MA), 2-ethylanthracene (2EA), and 2-tert-butylanthracene (2TBA) adsorbed on silica were studied at a silica/air interface. 2MA, 2EA, and 2TBA showed no evidence of ground state pairing even at high surface coverages, and crystallized on the surface at higher surface coverages. The photolysis of 2MA, 2EA, and 2TBA at a silica/air interface proceeded more efficiently than the photolysis of anthracene, to produce the corresponding 9,10-endoperoxides formed by the addition of singlet molecular oxygen (type II) to the ground state molecules. At low surface coverages, no evidence of any dimer was observed in photolyzed 2MA, 2EA, and 2TBA samples. A small amount of dimers (isomeric) were observed at higher surface coverages, suggesting that the crystal forms of these molecules may be involved in the dimerization process. The photolysis rate decreased with increasing surface coverage, due to an inner effect induced by crystal formation. Photolysis rate decreased by an order of magnitude in the presence of 1 monolayer of physisorbed water. Time-resolved transient studies of excited triplet states of 2MA, 2EA, and 2TBA showed that triplet lifetimes were shortened on wet silica. The efficiency of singlet molecular oxygen formation significantly decreased on wet silica. These results indicated that decreased photolysis rate was caused by reduced singlet quantum yield in the presence of physisorbed water.
- Dabestani, Reza,Higgin, Jashua,Stephenson, Daniel,Ivanov, Ilia N.,Sigman, Michael E.
-
p. 10235 - 10241
(2007/10/03)
-
- INVESTIGATION OF THE COMPOSITION OF PETROLEUM ANTHRACENE HYDROCARBONS
-
The optimum conditions of adduct formation with maleic anhydride for the isolation of ca. 100percent anthracene hydrocarbons from a mixture with phenanthrenes and other compounds are set out.Gas-liquid chromatography has been used to study the individual composition of anthracene and C1-C3 anthracenes isolated by the method proposed from concentrates of triaromatic hydrocarbons of crude oils from the Okha, Katangli (Sakhalin) and Dorokhovsk (Urals-Volga) fields.With the aid of the individual compounds synthesized, for the first time 2-ethylanthracene and 1,3- and 2,3-dimethylanthracene have been identified in crude oils, and the retention indices have also been calculated for certain C2- and C3-substituted anthracene hydrocarbons for chromatographic phase SE-54.
- Ivanov, V. I.,Golovko, A. K.
-
p. 504 - 512
(2007/10/02)
-
- Process for preparation of 2-substituted 1,4-naphthoquinone
-
A process for preparation of a 2-substituted-1,4-naphthoquinone which comprises oxidizing a 2-substituted naphthalene to obtain reaction products comprising a 2-substituted-1,4-naphthoquinone and a 6-substituted-1,4-naphthoquinone; adding a diene compound to the reaction products and heating the mixture to form a Diels-Alder reaction adduct between the diene compound and the 6-substituted-1,4-naphthoquinone in the reaction products; and separating the 2-substituted-1,4-naphthoquinone from the adduct.
- -
-
-
- REACTION OF ALKYL RADICALS WITH ANTHRAQUINONE
-
The thermal decomposition of propionyl and lauroyl peroxides in chlorobenzene and benzene was used as a source of alkyl radicals for the production of α- and β-alkylanthraquinones from anthraquinone.The process was realized at 80-140 deg C with anthraquinone-diacyl peroxide molar ratios between 2:1 and 1:2.The yields of the alkylanthraquinones amounted to 10percent on the reacted diacyl peroxide.
- Opeida, I. A.,Timokhin, V. I.,Mironenko, N. I.,Simonov, M. A.,Petrenko, V. V.
-
p. 1161 - 1163
(2007/10/02)
-
- Process for the preparation of anthraquinone and its substituted derivatives
-
A process for the preparation of anthraquinone compounds by condensation of phthalic anhydride with a benzene derivative wherein a mixture of hydrofluoric acid and boron trifluoride is utilized as catalyst.
- -
-
-
- Process for the production of substituted anthraquinones
-
Substituted anthraquinones are obtained by thermal or catalytic dehydrochlorination of the corresponding substituted ortho-benzoylbenzoic acid chloride. They may be used for the production of hydrogen peroxide and the synthesis of dyes.
- -
-
-
