The Experts below are selected from a list of 240 Experts worldwide ranked by ideXlab platform
Dušan Mravec - One of the best experts on this subject based on the ideXlab platform.
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tert-Butylation of Diphenylamine over zeolite catalysts comparison of different alkylation agents and catalysts
Catalysis Communications, 2012Co-Authors: Gabriel Kostrab, Martin Lovič, Andrej Turan, Pavol Hudec, Alexander Kaszonyi, Martin Bajus, Jan Uhlar, Peter Lehocký, Dušan MravecAbstract:Abstract tert -Butylation of Diphenylamine (DPA) with different tert -butylation agents isobutylene (IB), tert -butanol (TBA), and C 4 -fraction (C4-IB) in the liquid phase was studied over zeolite catalyst H-BEA (H-BEA CP 814E). This zeolite and acidic clay catalysts Nobelin and Fulcat 22B were compared in tert -butylation of Diphenylamine with isobutylene and tert -butanol. The study of the influence of tert -butylation agents in alkylation of DPA over H-BEA showed that isobutylene is the most suitable in tert -butylation of Diphenylamine over the particular H-BEA zeolite catalyst in terms of conversion and selectivity to desired products. Comparative study of catalyst type influence on tert -butylation of DPA with TBA and IB employed zeolite catalyst H-BEA and two clay ones Nobelin and Fulcat 22B. The study showed that all catalysts perform well in alkylation of DPA but H-BEA with the highest total acidity is the most active. tert -Butylation of Diphenylamine over H-BEA zeolite catalyst and acidic clays appears to be an environmental alternative to other catalysts (e.g. Friedel-Crafts) in industrial preparation of tert -butylated Diphenylamines.
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Tert-Butylation of Diphenylamine over zeolite catalysts Part 1: Catalyst screening and optimization of reaction conditions
Applied Catalysis A: General, 2008Co-Authors: Gabriel Kostrab, Martin Lovič, Martin Bajus, Ivan Janotka, Dušan MravecAbstract:Abstract tert-Butylation of Diphenylamine (DPA) with tert-butanol (TBA) in the liquid phase was studied over various zeolite catalysts H-MOR, H-BEA, H-Y and H-ZSM-5 (H-MOR CBV 21A and 90A, H-BEA CP 811E, 814E and 814Q, H-Y CBV 720 and H-ZSM-5 CBV 5020) to evaluate whether zeolite catalysts can be efficient as an alternative to the other catalysts in preparation of tert-butylated Diphenylamines. The influence of catalyst and the reaction conditions on tert-butylation of Diphenylamine with TBA as alkylating agent on catalytic activity and para-selectivity was studied. Catalyst screening revealed that H-BEA and H-Y are the most suitable zeolite catalysts in the alkylation of DPA with TBA. Among them, H-BEA CBV 814E showed the best results in the catalytic activity (91% conversion of DPA), selectivity (99% selectivity to 4-TBDPA, 91% selectivity to 4,4′-DTBDPA) and dialkylation (0.62 4,4′-DTBDPA/4-TBDPA ratio). Subsequent optimization of reaction conditions in the tert-butylation of DPA with TBA over H-BEA CBV 814E showed that the most suitable reaction temperature is 180 °C. The study of influence of reactant's molar ratio showed that TBA/DPA molar ratio 4:1 is the most suitable, but the excess of TBA is so high that it produces significant amount of isobutylene dimer (15%). However, TBA/DPA molar ratio 2:1 is comparable to 4:1, it is even better when considering the most important parameter—selectivity to 4,4′-DTBDPA and produces almost no isobutylene dimer (below 1%). The amount of catalyst charged into reaction system also significantly influences reaction parameters. Study shows that within wide range of catalyst charge (2.5% up to 30% as of DPA charge), the highest reasonable amount of catalyst with the best outcome can be obtained with 0.7 g (20% as of DPA charge) of catalyst charge in the reaction system. tert-Butylation of Diphenylamine with tert-butanol over H-BEA zeolite catalyst appears to be an alternative to other catalysts in industrial preparation of tert-butylated Diphenylamines. This paper presents the first original complex outlook on the tert-butylation of Diphenylamine over zeolite catalysts.
Gabriel Kostrab - One of the best experts on this subject based on the ideXlab platform.
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tert-Butylation of Diphenylamine over zeolite catalysts comparison of different alkylation agents and catalysts
Catalysis Communications, 2012Co-Authors: Gabriel Kostrab, Martin Lovič, Andrej Turan, Pavol Hudec, Alexander Kaszonyi, Martin Bajus, Jan Uhlar, Peter Lehocký, Dušan MravecAbstract:Abstract tert -Butylation of Diphenylamine (DPA) with different tert -butylation agents isobutylene (IB), tert -butanol (TBA), and C 4 -fraction (C4-IB) in the liquid phase was studied over zeolite catalyst H-BEA (H-BEA CP 814E). This zeolite and acidic clay catalysts Nobelin and Fulcat 22B were compared in tert -butylation of Diphenylamine with isobutylene and tert -butanol. The study of the influence of tert -butylation agents in alkylation of DPA over H-BEA showed that isobutylene is the most suitable in tert -butylation of Diphenylamine over the particular H-BEA zeolite catalyst in terms of conversion and selectivity to desired products. Comparative study of catalyst type influence on tert -butylation of DPA with TBA and IB employed zeolite catalyst H-BEA and two clay ones Nobelin and Fulcat 22B. The study showed that all catalysts perform well in alkylation of DPA but H-BEA with the highest total acidity is the most active. tert -Butylation of Diphenylamine over H-BEA zeolite catalyst and acidic clays appears to be an environmental alternative to other catalysts (e.g. Friedel-Crafts) in industrial preparation of tert -butylated Diphenylamines.
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Tert-Butylation of Diphenylamine over zeolite catalysts Part 1: Catalyst screening and optimization of reaction conditions
Applied Catalysis A: General, 2008Co-Authors: Gabriel Kostrab, Martin Lovič, Martin Bajus, Ivan Janotka, Dušan MravecAbstract:Abstract tert-Butylation of Diphenylamine (DPA) with tert-butanol (TBA) in the liquid phase was studied over various zeolite catalysts H-MOR, H-BEA, H-Y and H-ZSM-5 (H-MOR CBV 21A and 90A, H-BEA CP 811E, 814E and 814Q, H-Y CBV 720 and H-ZSM-5 CBV 5020) to evaluate whether zeolite catalysts can be efficient as an alternative to the other catalysts in preparation of tert-butylated Diphenylamines. The influence of catalyst and the reaction conditions on tert-butylation of Diphenylamine with TBA as alkylating agent on catalytic activity and para-selectivity was studied. Catalyst screening revealed that H-BEA and H-Y are the most suitable zeolite catalysts in the alkylation of DPA with TBA. Among them, H-BEA CBV 814E showed the best results in the catalytic activity (91% conversion of DPA), selectivity (99% selectivity to 4-TBDPA, 91% selectivity to 4,4′-DTBDPA) and dialkylation (0.62 4,4′-DTBDPA/4-TBDPA ratio). Subsequent optimization of reaction conditions in the tert-butylation of DPA with TBA over H-BEA CBV 814E showed that the most suitable reaction temperature is 180 °C. The study of influence of reactant's molar ratio showed that TBA/DPA molar ratio 4:1 is the most suitable, but the excess of TBA is so high that it produces significant amount of isobutylene dimer (15%). However, TBA/DPA molar ratio 2:1 is comparable to 4:1, it is even better when considering the most important parameter—selectivity to 4,4′-DTBDPA and produces almost no isobutylene dimer (below 1%). The amount of catalyst charged into reaction system also significantly influences reaction parameters. Study shows that within wide range of catalyst charge (2.5% up to 30% as of DPA charge), the highest reasonable amount of catalyst with the best outcome can be obtained with 0.7 g (20% as of DPA charge) of catalyst charge in the reaction system. tert-Butylation of Diphenylamine with tert-butanol over H-BEA zeolite catalyst appears to be an alternative to other catalysts in industrial preparation of tert-butylated Diphenylamines. This paper presents the first original complex outlook on the tert-butylation of Diphenylamine over zeolite catalysts.
Kiminori Ohta - One of the best experts on this subject based on the ideXlab platform.
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Diphenylamine-based retinoid antagonists: regulation of RAR and RXR function depending on the N-substituent.
Bioorganic & medicinal chemistry, 2011Co-Authors: Kiminori Ohta, Emiko Kawachi, Hiroshi Fukasawa, Koichi Shudo, Hiroyuki KagechikaAbstract:Abstract Based upon the structure–activity relationships of Diphenylamine derivatives with retinoid synergistic activity (RXR agonists), novel Diphenylamine derivatives with a long alkyl chain (9a and 9b) or a benzyl group (10a–f) as the N-substituent were designed and synthesized. All the synthesized compounds dose-dependently inhibited HL-60 cell differentiation induced by 3.3 × 10−10 M Am80. Among them, compound 10f showed the most potent inhibitory activity, and the mechanism was shown, by means of transactivation assay for RARs and RXRs, to involve antagonism against RARs. The N-substituent of the Diphenylamine skeleton plays an important role in determining the receptor selectivity for RARs or RXRs, as well as the agonist or antagonist nature of the activity.
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promising core structure for nuclear receptor ligands design and synthesis of novel estrogen receptor ligands based on Diphenylamine skeleton
Bioorganic & Medicinal Chemistry Letters, 2008Co-Authors: Kiminori Ohta, Yuki Chiba, Takumi Ogawa, Yasuyuki EndoAbstract:Abstract Novel Diphenylamine-type estrogen receptor ligands were designed and synthesized, and their biological activities were evaluated by means of binding assays for estrogen receptor-α and -β and cell proliferation assay using MCF-7 cells. Compounds 4f, 11b, 12c, and 8 showed moderate estrogenic activities. We propose that the Diphenylamine skeleton may be a privileged structure for various nuclear receptor ligands, including RAR, RXR, and AR ligands.
Martin Lovič - One of the best experts on this subject based on the ideXlab platform.
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tert-Butylation of Diphenylamine over zeolite catalysts comparison of different alkylation agents and catalysts
Catalysis Communications, 2012Co-Authors: Gabriel Kostrab, Martin Lovič, Andrej Turan, Pavol Hudec, Alexander Kaszonyi, Martin Bajus, Jan Uhlar, Peter Lehocký, Dušan MravecAbstract:Abstract tert -Butylation of Diphenylamine (DPA) with different tert -butylation agents isobutylene (IB), tert -butanol (TBA), and C 4 -fraction (C4-IB) in the liquid phase was studied over zeolite catalyst H-BEA (H-BEA CP 814E). This zeolite and acidic clay catalysts Nobelin and Fulcat 22B were compared in tert -butylation of Diphenylamine with isobutylene and tert -butanol. The study of the influence of tert -butylation agents in alkylation of DPA over H-BEA showed that isobutylene is the most suitable in tert -butylation of Diphenylamine over the particular H-BEA zeolite catalyst in terms of conversion and selectivity to desired products. Comparative study of catalyst type influence on tert -butylation of DPA with TBA and IB employed zeolite catalyst H-BEA and two clay ones Nobelin and Fulcat 22B. The study showed that all catalysts perform well in alkylation of DPA but H-BEA with the highest total acidity is the most active. tert -Butylation of Diphenylamine over H-BEA zeolite catalyst and acidic clays appears to be an environmental alternative to other catalysts (e.g. Friedel-Crafts) in industrial preparation of tert -butylated Diphenylamines.
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Tert-Butylation of Diphenylamine over zeolite catalysts Part 1: Catalyst screening and optimization of reaction conditions
Applied Catalysis A: General, 2008Co-Authors: Gabriel Kostrab, Martin Lovič, Martin Bajus, Ivan Janotka, Dušan MravecAbstract:Abstract tert-Butylation of Diphenylamine (DPA) with tert-butanol (TBA) in the liquid phase was studied over various zeolite catalysts H-MOR, H-BEA, H-Y and H-ZSM-5 (H-MOR CBV 21A and 90A, H-BEA CP 811E, 814E and 814Q, H-Y CBV 720 and H-ZSM-5 CBV 5020) to evaluate whether zeolite catalysts can be efficient as an alternative to the other catalysts in preparation of tert-butylated Diphenylamines. The influence of catalyst and the reaction conditions on tert-butylation of Diphenylamine with TBA as alkylating agent on catalytic activity and para-selectivity was studied. Catalyst screening revealed that H-BEA and H-Y are the most suitable zeolite catalysts in the alkylation of DPA with TBA. Among them, H-BEA CBV 814E showed the best results in the catalytic activity (91% conversion of DPA), selectivity (99% selectivity to 4-TBDPA, 91% selectivity to 4,4′-DTBDPA) and dialkylation (0.62 4,4′-DTBDPA/4-TBDPA ratio). Subsequent optimization of reaction conditions in the tert-butylation of DPA with TBA over H-BEA CBV 814E showed that the most suitable reaction temperature is 180 °C. The study of influence of reactant's molar ratio showed that TBA/DPA molar ratio 4:1 is the most suitable, but the excess of TBA is so high that it produces significant amount of isobutylene dimer (15%). However, TBA/DPA molar ratio 2:1 is comparable to 4:1, it is even better when considering the most important parameter—selectivity to 4,4′-DTBDPA and produces almost no isobutylene dimer (below 1%). The amount of catalyst charged into reaction system also significantly influences reaction parameters. Study shows that within wide range of catalyst charge (2.5% up to 30% as of DPA charge), the highest reasonable amount of catalyst with the best outcome can be obtained with 0.7 g (20% as of DPA charge) of catalyst charge in the reaction system. tert-Butylation of Diphenylamine with tert-butanol over H-BEA zeolite catalyst appears to be an alternative to other catalysts in industrial preparation of tert-butylated Diphenylamines. This paper presents the first original complex outlook on the tert-butylation of Diphenylamine over zeolite catalysts.
Martin Bajus - One of the best experts on this subject based on the ideXlab platform.
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tert-Butylation of Diphenylamine over zeolite catalysts comparison of different alkylation agents and catalysts
Catalysis Communications, 2012Co-Authors: Gabriel Kostrab, Martin Lovič, Andrej Turan, Pavol Hudec, Alexander Kaszonyi, Martin Bajus, Jan Uhlar, Peter Lehocký, Dušan MravecAbstract:Abstract tert -Butylation of Diphenylamine (DPA) with different tert -butylation agents isobutylene (IB), tert -butanol (TBA), and C 4 -fraction (C4-IB) in the liquid phase was studied over zeolite catalyst H-BEA (H-BEA CP 814E). This zeolite and acidic clay catalysts Nobelin and Fulcat 22B were compared in tert -butylation of Diphenylamine with isobutylene and tert -butanol. The study of the influence of tert -butylation agents in alkylation of DPA over H-BEA showed that isobutylene is the most suitable in tert -butylation of Diphenylamine over the particular H-BEA zeolite catalyst in terms of conversion and selectivity to desired products. Comparative study of catalyst type influence on tert -butylation of DPA with TBA and IB employed zeolite catalyst H-BEA and two clay ones Nobelin and Fulcat 22B. The study showed that all catalysts perform well in alkylation of DPA but H-BEA with the highest total acidity is the most active. tert -Butylation of Diphenylamine over H-BEA zeolite catalyst and acidic clays appears to be an environmental alternative to other catalysts (e.g. Friedel-Crafts) in industrial preparation of tert -butylated Diphenylamines.
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Tert-Butylation of Diphenylamine over zeolite catalysts Part 1: Catalyst screening and optimization of reaction conditions
Applied Catalysis A: General, 2008Co-Authors: Gabriel Kostrab, Martin Lovič, Martin Bajus, Ivan Janotka, Dušan MravecAbstract:Abstract tert-Butylation of Diphenylamine (DPA) with tert-butanol (TBA) in the liquid phase was studied over various zeolite catalysts H-MOR, H-BEA, H-Y and H-ZSM-5 (H-MOR CBV 21A and 90A, H-BEA CP 811E, 814E and 814Q, H-Y CBV 720 and H-ZSM-5 CBV 5020) to evaluate whether zeolite catalysts can be efficient as an alternative to the other catalysts in preparation of tert-butylated Diphenylamines. The influence of catalyst and the reaction conditions on tert-butylation of Diphenylamine with TBA as alkylating agent on catalytic activity and para-selectivity was studied. Catalyst screening revealed that H-BEA and H-Y are the most suitable zeolite catalysts in the alkylation of DPA with TBA. Among them, H-BEA CBV 814E showed the best results in the catalytic activity (91% conversion of DPA), selectivity (99% selectivity to 4-TBDPA, 91% selectivity to 4,4′-DTBDPA) and dialkylation (0.62 4,4′-DTBDPA/4-TBDPA ratio). Subsequent optimization of reaction conditions in the tert-butylation of DPA with TBA over H-BEA CBV 814E showed that the most suitable reaction temperature is 180 °C. The study of influence of reactant's molar ratio showed that TBA/DPA molar ratio 4:1 is the most suitable, but the excess of TBA is so high that it produces significant amount of isobutylene dimer (15%). However, TBA/DPA molar ratio 2:1 is comparable to 4:1, it is even better when considering the most important parameter—selectivity to 4,4′-DTBDPA and produces almost no isobutylene dimer (below 1%). The amount of catalyst charged into reaction system also significantly influences reaction parameters. Study shows that within wide range of catalyst charge (2.5% up to 30% as of DPA charge), the highest reasonable amount of catalyst with the best outcome can be obtained with 0.7 g (20% as of DPA charge) of catalyst charge in the reaction system. tert-Butylation of Diphenylamine with tert-butanol over H-BEA zeolite catalyst appears to be an alternative to other catalysts in industrial preparation of tert-butylated Diphenylamines. This paper presents the first original complex outlook on the tert-butylation of Diphenylamine over zeolite catalysts.