Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyldiphenylmethane, benzyl toluene and benzoic acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was ...Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyldiphenylmethane, benzyl toluene and benzoic acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was systematically studied over plane clay (K-10, montmorillonite), plane H-Beta, plane MFI structured titanosilicate (TS-1) and heteropoly acids [HPA, namely dodecatungstophosphoric acid [H3PO4.12WOa-xH2O] (TPA), dodeca-molybdo phosphoric acid ammonium salt hydrate [H12Mo12N3040P+aq] (DMAA), sodium tungstate hydrated purified [Na12WO4.2H2O] (STH)] supported on clay, H-beta and TS-1. The 20%TPA/Clay, 30%TPA/H-Beta and 30%TPA/TS-1, were observed to be the best catalyst samples over plane clay, plane H-Beta and plane TS-1. The catalyst samples are compared with respect to benzyl chloride conversion and selectivities for diphenylmethane, dimethyl-diphenylmethane, benzyl toluene and benzoic acid. The reaction follows the pseudo-first order rate power law model. The apparent rate constants are calculated and compared with the reported ones.展开更多
The incidence of cathartic colon has been increasing,but satisfactory treatments are still lacking.In order to study the pathological mechanisms of the disorder and identify effective treatment methods,researchers hav...The incidence of cathartic colon has been increasing,but satisfactory treatments are still lacking.In order to study the pathological mechanisms of the disorder and identify effective treatment methods,researchers have established different animal models of cathartic colon.This minireview briefly summarizes several common cathartic colon animal models,induced with anthraquinone laxatives such as rhubarb,total anthraquinone,rhein,and emodin,or induced with diphenylmethane laxatives such as phenolphthalein.The advantages and limitations of these models are evaluated and analyzed.We hope that this review will facilitate the selection of suitable models and improve relevant modeling methods.We anticipate the development of more convenient and stable models that can reflect the characteristics of cathartic colon in humans,and serve as useful tools for further studies.展开更多
Selective oxidation of diphenylmethane to benzophenone requires active and selective catalysts. The framework incorporation of cerium in AlPO-5 molecular sieves creates active cerium sites in isolation. These active s...Selective oxidation of diphenylmethane to benzophenone requires active and selective catalysts. The framework incorporation of cerium in AlPO-5 molecular sieves creates active cerium sites in isolation. These active sites are responsible for selective oxidation. Cerium incorporated AlPO-5 with different Al/Ce ratios were synthesized, and the vapor phase oxidation of diphenylmethane in air over these catalysts was studied at 250, 275, 300, 325, and 350 °C. The diphenylmethane conversion and selectivity for benzophenone were more than 90%. CeAlPO-5(25) was found to be more active than other catalysts. The stability of the catalyst was verified by the time on stream study which indicated steady diphenylmethane conversion and benzophenone selectivity. Hence framework incorporated CeAlPO-5 molecular sieves are stable and active catalysts for the selective oxidation of diphenylmethane.展开更多
FeO_x/HZSM-5 catalyst with 8 wt.%Fe-loading(8-FeZ) exhibited significantly higher reactivity in the benzylation of benzene with benzyl chloride than FeO_x/HZSM-5 catalyst with 2.5 wt.%Fe-loading(2.5-FeZ) because t...FeO_x/HZSM-5 catalyst with 8 wt.%Fe-loading(8-FeZ) exhibited significantly higher reactivity in the benzylation of benzene with benzyl chloride than FeO_x/HZSM-5 catalyst with 2.5 wt.%Fe-loading(2.5-FeZ) because the synergistic catalysis between isolated Fe^(3+) and superfine Fe_2O_3 occurred on 8-FeZ in the reaction.展开更多
A novel 2,6-dimethyl-b-CD bonded and silica based HPLC chiral stationary phase(CSP) was prepared.The diphenylmethane diisocyanate(MDI) was applied for the first time in the immobilization of 2,6-dimethyl-b-CD onto...A novel 2,6-dimethyl-b-CD bonded and silica based HPLC chiral stationary phase(CSP) was prepared.The diphenylmethane diisocyanate(MDI) was applied for the first time in the immobilization of 2,6-dimethyl-b-CD onto the surface of aminized silica gel under mild conditions. The composite materials obtained were used as the CSP for chiral separation processes and this kind of CSP exhibits good enantioselectivity for a variety of chiral compounds under reversed-phase conditions.展开更多
文摘Selective formation of pharmaceutical intermediates like diphenylmethane, dimethyldiphenylmethane, benzyl toluene and benzoic acid by liquid phase, toluene benzylation with benzyl chloride as a benzylating agent, was systematically studied over plane clay (K-10, montmorillonite), plane H-Beta, plane MFI structured titanosilicate (TS-1) and heteropoly acids [HPA, namely dodecatungstophosphoric acid [H3PO4.12WOa-xH2O] (TPA), dodeca-molybdo phosphoric acid ammonium salt hydrate [H12Mo12N3040P+aq] (DMAA), sodium tungstate hydrated purified [Na12WO4.2H2O] (STH)] supported on clay, H-beta and TS-1. The 20%TPA/Clay, 30%TPA/H-Beta and 30%TPA/TS-1, were observed to be the best catalyst samples over plane clay, plane H-Beta and plane TS-1. The catalyst samples are compared with respect to benzyl chloride conversion and selectivities for diphenylmethane, dimethyl-diphenylmethane, benzyl toluene and benzoic acid. The reaction follows the pseudo-first order rate power law model. The apparent rate constants are calculated and compared with the reported ones.
基金Supported by Xinglin Scholar,Xinglin Young Talent Program,No.RC-2017-02-07Shanghai Three-year Action Plan for Accelerating the Development of Traditional Chinese Medicine,No.ZY(2018-2020)-CCCX-2002-01and Research Fund of Longhua Hospital,No.2018YM05.
文摘The incidence of cathartic colon has been increasing,but satisfactory treatments are still lacking.In order to study the pathological mechanisms of the disorder and identify effective treatment methods,researchers have established different animal models of cathartic colon.This minireview briefly summarizes several common cathartic colon animal models,induced with anthraquinone laxatives such as rhubarb,total anthraquinone,rhein,and emodin,or induced with diphenylmethane laxatives such as phenolphthalein.The advantages and limitations of these models are evaluated and analyzed.We hope that this review will facilitate the selection of suitable models and improve relevant modeling methods.We anticipate the development of more convenient and stable models that can reflect the characteristics of cathartic colon in humans,and serve as useful tools for further studies.
基金supported by the Department of Science and Technology (DST, SR/S1/PC-10/2009)Government of India, New Delhithe University Grants Commission (UGC), New Delhi
文摘Selective oxidation of diphenylmethane to benzophenone requires active and selective catalysts. The framework incorporation of cerium in AlPO-5 molecular sieves creates active cerium sites in isolation. These active sites are responsible for selective oxidation. Cerium incorporated AlPO-5 with different Al/Ce ratios were synthesized, and the vapor phase oxidation of diphenylmethane in air over these catalysts was studied at 250, 275, 300, 325, and 350 °C. The diphenylmethane conversion and selectivity for benzophenone were more than 90%. CeAlPO-5(25) was found to be more active than other catalysts. The stability of the catalyst was verified by the time on stream study which indicated steady diphenylmethane conversion and benzophenone selectivity. Hence framework incorporated CeAlPO-5 molecular sieves are stable and active catalysts for the selective oxidation of diphenylmethane.
基金financially supported by Ministry of Education(No.NCET-10-878,20096101120018,2009-37th of SRFROCS)Shaanxi Province(No.2009ZDKG-70,09JK793)+1 种基金Northwest University(No.PR200905)State Key Lab for SSPC(2009)
文摘FeO_x/HZSM-5 catalyst with 8 wt.%Fe-loading(8-FeZ) exhibited significantly higher reactivity in the benzylation of benzene with benzyl chloride than FeO_x/HZSM-5 catalyst with 2.5 wt.%Fe-loading(2.5-FeZ) because the synergistic catalysis between isolated Fe^(3+) and superfine Fe_2O_3 occurred on 8-FeZ in the reaction.
文摘A novel 2,6-dimethyl-b-CD bonded and silica based HPLC chiral stationary phase(CSP) was prepared.The diphenylmethane diisocyanate(MDI) was applied for the first time in the immobilization of 2,6-dimethyl-b-CD onto the surface of aminized silica gel under mild conditions. The composite materials obtained were used as the CSP for chiral separation processes and this kind of CSP exhibits good enantioselectivity for a variety of chiral compounds under reversed-phase conditions.