The Experts below are selected from a list of 249 Experts worldwide ranked by ideXlab platform
Suguna S. Naik - One of the best experts on this subject based on the ideXlab platform.
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clay supported liquid liquid solid phase transfer catalysis synthesis of Benzoic Anhydride
Organic Process Research & Development, 2000Co-Authors: G Yadav D And, Suguna S. NaikAbstract:Solid-supported phase transfer catalysed reactions typically involve polystyrene supports cross-linked with divinyl benzene. The use of commercially available clay as a support for the PTC reaction is attractive. This paper reports the preparation of Benzoic Anhydride from benzoyl chloride and sodium benzoate using clay-supported quaternary ammonium salts at 30 °C. The selectivity to the product is 100%. The mechanistic and kinetic aspects are also reported. The clay-supported catalyst was found to be more active than polymer-supported catalysts.
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Clay-Supported Liquid−Liquid−Solid Phase Transfer Catalysis: Synthesis of Benzoic Anhydride
Organic Process Research & Development, 2000Co-Authors: G. D. Yadav And, Suguna S. NaikAbstract:Solid-supported phase transfer catalysed reactions typically involve polystyrene supports cross-linked with divinyl benzene. The use of commercially available clay as a support for the PTC reaction is attractive. This paper reports the preparation of Benzoic Anhydride from benzoyl chloride and sodium benzoate using clay-supported quaternary ammonium salts at 30 °C. The selectivity to the product is 100%. The mechanistic and kinetic aspects are also reported. The clay-supported catalyst was found to be more active than polymer-supported catalysts.
Ganapati D. Yadav - One of the best experts on this subject based on the ideXlab platform.
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Novel alkali-promoted hydrotalcite for selective synthesis of 2-methoxy phenyl benzoate from guaiacol and Benzoic Anhydride
Clean Technologies and Environmental Policy, 2017Co-Authors: Shivaji L. Bhanawase, Ganapati D. YadavAbstract:Esters find several applications such as solvents, flavours and fragrants and intermediates in synthesis of drugs. In the present work, 2-methoxy phenyl benzoate was efficiently synthesized from guaiacol and Benzoic Anhydride by acylation. A variety of catalysts such as hydrotalcite and alkali-promoted hydrotalcite was synthesized. Potassium-promoted hydrotalcite (K/HT) calcined at 500 °C for 6 h was active, selective and reusable. It was characterized by different techniques. A slurry batch reactor was used to study reaction mechanism and kinetics. 2-Methoxy phenyl benzoate was efficiently obtained with 100% selectivity at guaiacol conversion of 98% over K/HT at 100 °C after 6 h. A power law model with second-order kinetics was fitted to obtain an apparent activation energy of reaction of 21.1 kcal mol^−1. The process is clean and green.
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Novel aluminium exchanged dodecatungstophosphoric acid supported on K-10 clay as catalyst: benzoylation of diphenyloxide with Benzoic Anhydride
RSC Advances, 2016Co-Authors: Manishkumar S. Tiwari, Ganapati D. YadavAbstract:A series of (20% w/w) aluminium exchanged dodeca-tungstophosphoric acids (DTP) (Alx-DTP, x = 0.33–1) supported on montmorillonite K-10 clay were synthesized and completely characterized by sophisticated techniques. These catalysts were used for the selective benzoylation of diphenyl oxide with Benzoic Anhydride to a mono acylated product. Al0.66-DTP/K-10 catalyst showed the best activity amongst other aluminium substituted catalysts and Cs2.5H0.5PW12O40 (Cs-DTP)/K-10. Different supports such as ZrO2, SnO2 and K-10 were used to study the effect of support on the acidic property and activity of Al0.66-DTP supported catalysts in the benzoylation reaction. The order of activity was Al0.66-DTP/K-10 > Al0.66-DTP/SnO2 > Al0.66-DTP/ZrO2. The effect of benzoylating agents such as Benzoic Anhydride, benzoyl chloride and Benzoic acid on the conversion and rate was also studied. Benzoic Anhydride showed the highest reactivity. Eley–Rideal mechanism was found to be consistent with the data. The activation energy for benzoylation of DPO was calculated as 22 kcal mol−1, which further supports that the reaction is kinetically controlled. Al0.66-DTP/K-10 was an active and robust catalyst.
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kinetics of friedel crafts benzoylation of veratrole with Benzoic Anhydride using cs2 5h0 5pw12o40 k 10 solid acid catalyst
Chemical Engineering Journal, 2015Co-Authors: Manishkumar S. Tiwari, Ganapati D. YadavAbstract:Abstract Friedel–Crafts alkylation and acylation reactions are ubiquitous in several industries and use highly polluting liquid acids as catalysts. Production of ketones and subsequently secondary alcohols is achieved by Friedel Crafts acylation using various acylating agents. Benzophenone and its family are used in intermediates, fine chemicals, dyes and pharmaceuticals industries. Use of homogeneous catalysts in benzoylation of veratrole (1,2-dimethoxybenzene) to produce 3,4-dimethoxybenzophenone (DMBP) is highly polluting. The current work deals with solvent free reaction of veratrole and Benzoic Anhydride to produce 3,4-DMBP by using different solid super acids such as 20% (w/w) Cs 2.5 H 0.5 PW 12 O 40 /K-10 clay (Cs-DTP/K-10), UDCaT-5, sulfated zirconia (S-ZrO 2 ), unsupported Cs-DTP and montmorillonite K-10 clay. Cs-DTP/K-10 was found to be best catalyst for this reaction. At a mole ratio of 1:5 of Benzoic Anhydride to veratrole, the solvent free reaction gave 89.3% conversion at 90 °C in 2 h at catalyst loading of 4% (w/v). The selectivity was 100%. The catalyst is robust and reusable. It was characterized before and after use to find its fidelity. The effect of different parameters on the rate of reaction and conversion of veratrole was studied systematically to deduce kinetics of the benzoylation reaction. The reaction follows Eley–Rideal mechanism with weak adsorption of Benzoic Anhydride. The apparent energy of activation is 20.8 kcal/mol.
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Kinetics of Friedel–Crafts benzoylation of veratrole with Benzoic Anhydride using Cs2.5H0.5PW12O40/K-10 solid acid catalyst
Chemical Engineering Journal, 2015Co-Authors: Manishkumar S. Tiwari, Ganapati D. YadavAbstract:Abstract Friedel–Crafts alkylation and acylation reactions are ubiquitous in several industries and use highly polluting liquid acids as catalysts. Production of ketones and subsequently secondary alcohols is achieved by Friedel Crafts acylation using various acylating agents. Benzophenone and its family are used in intermediates, fine chemicals, dyes and pharmaceuticals industries. Use of homogeneous catalysts in benzoylation of veratrole (1,2-dimethoxybenzene) to produce 3,4-dimethoxybenzophenone (DMBP) is highly polluting. The current work deals with solvent free reaction of veratrole and Benzoic Anhydride to produce 3,4-DMBP by using different solid super acids such as 20% (w/w) Cs 2.5 H 0.5 PW 12 O 40 /K-10 clay (Cs-DTP/K-10), UDCaT-5, sulfated zirconia (S-ZrO 2 ), unsupported Cs-DTP and montmorillonite K-10 clay. Cs-DTP/K-10 was found to be best catalyst for this reaction. At a mole ratio of 1:5 of Benzoic Anhydride to veratrole, the solvent free reaction gave 89.3% conversion at 90 °C in 2 h at catalyst loading of 4% (w/v). The selectivity was 100%. The catalyst is robust and reusable. It was characterized before and after use to find its fidelity. The effect of different parameters on the rate of reaction and conversion of veratrole was studied systematically to deduce kinetics of the benzoylation reaction. The reaction follows Eley–Rideal mechanism with weak adsorption of Benzoic Anhydride. The apparent energy of activation is 20.8 kcal/mol.
Kazushi Arata - One of the best experts on this subject based on the ideXlab platform.
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friedel crafts benzoylation of alkylbenzenes with Benzoic Anhydride catalyzed by solid superacids
Bulletin of the Chemical Society of Japan, 2004Co-Authors: Hideo Nakamura, Kazushi ArataAbstract:The liquid-solid phase benzoylation of mono-alkylbenzenes with methyl, ethyl, propyl, and butyl groups and xylenes was carried out with Benzoic Anhydride at 100-110 °C over solid superacids: SO 4 /ZrO 2 , WO 3 /ZrO 2 , and SO 4 / HfO 2 . The reactivity ratio obtained by the competitive method of reaction over WO 3 /ZrO 2 was 1 to 4.6 for toluene to p-xylene and 1.1:10:1 among o-, m-, and p-xylenes, respectively. Although the SO 4 /ZrO 2 catalyst gave high yields of 92 and 97% for toluene and ethylbenzene in a 3:7 distribution of o- and p-isomers, respectively, low yields were observed with propyl and butylbenzenes over the catalyst: that is, 5 and 2% for propylbenzene and isopropylbenzene, 14% for isobutylbenzene, and trace yields for butylbenzene, s-butylbenzene, and t-butylbenzene, respectively. The usual Friedel-Crafts benzoylation using AlCl 3 was examined in the present alkylbenzenes in order to confirm the low reactivity of both propyl and butylbenzenes. The results were similar to those with the SO 4 /ZrO 2 catalyst; that is, the yields at 0°C for 1 h were 37, 21, 6, 1, 0, 3, and 2% for toluene, ethylbenzene, propylbenzene, isopropylbenzene, butylbenzene, s-butylbenzene, and t-butylbenzene, respectively, showing an unexpected result where there was no distinction between homogeneous and heterogeneous conditions.
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Friedel-Crafts benzoylation of alkylbenzenes with Benzoic Anhydride catalyzed by solid superacids
Bulletin of the Chemical Society of Japan, 2004Co-Authors: Hideo Nakamura, Kazushi ArataAbstract:The liquid–solid phase benzoylation of mono-alkylbenzenes with methyl, ethyl, propyl, and butyl groups and xylenes was carried out with Benzoic Anhydride at 100–110 °C over solid superacids: SO4/Zr...
Toyoshi Shimada - One of the best experts on this subject based on the ideXlab platform.
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Footprint Catalysis. XI. Molecular Footprint Cavities Imprinted with Chiral Amines and Their Chiral Molecular Recognition
Bulletin of the Chemical Society of Japan, 1994Co-Authors: Kensaku Morihara, Michie Takiguchi, Toyoshi ShimadaAbstract:Chiral amines, (R)- and (S)-N-benzyl-α-methylbenzylamine, served as templates in a molecular imprinting we developed. They formed “molecular footprint” cavities on a silica (alumina) gel surface, which showed catalytic activities toward transacylation of Benzoic Anhydride. The catalyses were susceptible to enantioselective inhibitions by the rebinding of the chiral template amines. This finding proved that the cavities could show chiral recognition through their chirally marked cavity structures.
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Footprint Catalysis. VIII. Molecular Imprinting for Footprint Cavities on an Active Clay Surface.
Bulletin of the Chemical Society of Japan, 1993Co-Authors: Kensaku Morihara, Tomoko Iijima, Hiromi Usui, Toyoshi ShimadaAbstract:Our molecular imprinting procedures were used for molecular footprint cavities formation on the surface of an amorphous clay mineral. The imprinting with a template, N-benzoylsulfonamide, generated footprint cavities on the surface of Japanese Active Clay (sulfuric acid-treated Japanese Acid Clay). The cavities showed specific catalysis toward transacylation of Benzoic Anhydride that served as a corresponding substrate. This finding provided an experimental clue to study the adsorption mechanism of the Active Clay surface that has hardly been defined so far. Additionally, our comments on the significance of footprint imprinting in chemical evolution are described briefly.
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Footprint Catalysis. IV. Structural Effects of Templates on Catalytic Behavior of Imprinted Footprint Cavities
Bulletin of the Chemical Society of Japan, 1992Co-Authors: Toyoshi Shimada, Kiyoko Nakanishi, Kensaku MoriharaAbstract:Footprint catalysts are silica(alumina)gel catalysts with tailored specificities. Their catalytic sites are “molecular footprint-like” cavities formed by a molecular imprinting procedure with templates, which are referred to as transition-state or reactive-intermediate analogs of the catalyzed reactions. To clarify the relationship between the structural feature of template molecules and catalytic behavior, seven footprint catalysts were prepared by imprinting with templates of several types closely related to the substrates, Benzoic Anhydride and acetic Anhydride; their catalytic activity and thermodynamic parameters for 2,4-dinitrophenolysis were then estimated. Among these catalysts, a catalyst imprinted with N,N′-dibenzoylbenzenephosphonediamide, a tetrahedral intermediate analog for Benzoic Anhydride substrate, showed a 10-fold higher catalytic activity than did the other imprinted catalysts.
Kensaku Morihara - One of the best experts on this subject based on the ideXlab platform.
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Footprint Catalysis. XI. Molecular Footprint Cavities Imprinted with Chiral Amines and Their Chiral Molecular Recognition
Bulletin of the Chemical Society of Japan, 1994Co-Authors: Kensaku Morihara, Michie Takiguchi, Toyoshi ShimadaAbstract:Chiral amines, (R)- and (S)-N-benzyl-α-methylbenzylamine, served as templates in a molecular imprinting we developed. They formed “molecular footprint” cavities on a silica (alumina) gel surface, which showed catalytic activities toward transacylation of Benzoic Anhydride. The catalyses were susceptible to enantioselective inhibitions by the rebinding of the chiral template amines. This finding proved that the cavities could show chiral recognition through their chirally marked cavity structures.
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Footprint Catalysis. VIII. Molecular Imprinting for Footprint Cavities on an Active Clay Surface.
Bulletin of the Chemical Society of Japan, 1993Co-Authors: Kensaku Morihara, Tomoko Iijima, Hiromi Usui, Toyoshi ShimadaAbstract:Our molecular imprinting procedures were used for molecular footprint cavities formation on the surface of an amorphous clay mineral. The imprinting with a template, N-benzoylsulfonamide, generated footprint cavities on the surface of Japanese Active Clay (sulfuric acid-treated Japanese Acid Clay). The cavities showed specific catalysis toward transacylation of Benzoic Anhydride that served as a corresponding substrate. This finding provided an experimental clue to study the adsorption mechanism of the Active Clay surface that has hardly been defined so far. Additionally, our comments on the significance of footprint imprinting in chemical evolution are described briefly.
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Footprint Catalysis. IV. Structural Effects of Templates on Catalytic Behavior of Imprinted Footprint Cavities
Bulletin of the Chemical Society of Japan, 1992Co-Authors: Toyoshi Shimada, Kiyoko Nakanishi, Kensaku MoriharaAbstract:Footprint catalysts are silica(alumina)gel catalysts with tailored specificities. Their catalytic sites are “molecular footprint-like” cavities formed by a molecular imprinting procedure with templates, which are referred to as transition-state or reactive-intermediate analogs of the catalyzed reactions. To clarify the relationship between the structural feature of template molecules and catalytic behavior, seven footprint catalysts were prepared by imprinting with templates of several types closely related to the substrates, Benzoic Anhydride and acetic Anhydride; their catalytic activity and thermodynamic parameters for 2,4-dinitrophenolysis were then estimated. Among these catalysts, a catalyst imprinted with N,N′-dibenzoylbenzenephosphonediamide, a tetrahedral intermediate analog for Benzoic Anhydride substrate, showed a 10-fold higher catalytic activity than did the other imprinted catalysts.