Enantioselective hydrogenation of ethyl 2-oxo-4-phenylbutyrate to ethyl （R）-2-hydroxy-4-phenyl- bu- tyrate on Pt/γ-Al2O3 modified by 10,11-dihydrocinchonidine was studied by investigating the influences of the amou...Enantioselective hydrogenation of ethyl 2-oxo-4-phenylbutyrate to ethyl （R）-2-hydroxy-4-phenyl- bu- tyrate on Pt/γ-Al2O3 modified by 10,11-dihydrocinchonidine was studied by investigating the influences of the amount of modifier, initial concentration of reactant, pressure and temperature on conversion and enantiometric excess in a stirred autoclave and the effects of the liquid velocity, gas velocity, modifier concentration and various catalytic beds in a trickle-bed reactor. The maximum optical yields were about 50% and 60% in the two types of reactors, respectively. It was assumed that the total hydrogenation rate included the reaction rates over the unmodified and modified active sites on platinum surface and a kinetic model, which fitted the experimental data well in autoclave, was obtained. A simplified plug-flow model was proposed to describe the bed average efficiency of trickle-bed reactor.展开更多
The crystal structure of the title compound, C26H27O6P, has been determined by single--crystal X-ray diffraction. The crystal is monoclinic with space groupP21, a=16. 193(l), b=5. 804(1), c=12. 512(2) A, β=93. 187(5)...The crystal structure of the title compound, C26H27O6P, has been determined by single--crystal X-ray diffraction. The crystal is monoclinic with space groupP21, a=16. 193(l), b=5. 804(1), c=12. 512(2) A, β=93. 187(5)°, V=1174. 13A3, Dc=1. 319 g/cm3, F(000) =492, μ= 13. 52 cm-1, Z= 2, and final R= 0. 042and Rw= 0. 040 for 2349 reflections (I≥3σ(I)). Structure analysis revealed that thepyranose and 4, 6-O-benzylidene ring of the title compound adopts a distorted chair conformation.展开更多
This research deals with an investigation of the adsorption of two acids, namely, 5-amino- 2-chlorotoluene-4-sulfonic and chlorhydric acids from their solution onto weakly basic resin. The screening of res-ins, kineti...This research deals with an investigation of the adsorption of two acids, namely, 5-amino- 2-chlorotoluene-4-sulfonic and chlorhydric acids from their solution onto weakly basic resin. The screening of res-ins, kinetics, and isotherm were studied. The results indicate that the D301R is more appropriate for the removal of acids from solution. The adsorption of acids obeys Langmuir isotherm and the first-order kinetics model. Sorptive affinity of the two acids on D301R was found to be in the order of 5-amino-2-chlorotoluene-4-sulfonic acid> chlorhydric acid. Thermodynamic parameters for the adsorption of acids were calculated and discussed. The maxi-mum removal of acids was observed around 97% and 76% at 25℃ for 5-amino-2-chlorotoluene-4-sulfonic acid and chlorhydric acid , respectively.展开更多
文摘Enantioselective hydrogenation of ethyl 2-oxo-4-phenylbutyrate to ethyl （R）-2-hydroxy-4-phenyl- bu- tyrate on Pt/γ-Al2O3 modified by 10,11-dihydrocinchonidine was studied by investigating the influences of the amount of modifier, initial concentration of reactant, pressure and temperature on conversion and enantiometric excess in a stirred autoclave and the effects of the liquid velocity, gas velocity, modifier concentration and various catalytic beds in a trickle-bed reactor. The maximum optical yields were about 50% and 60% in the two types of reactors, respectively. It was assumed that the total hydrogenation rate included the reaction rates over the unmodified and modified active sites on platinum surface and a kinetic model, which fitted the experimental data well in autoclave, was obtained. A simplified plug-flow model was proposed to describe the bed average efficiency of trickle-bed reactor.
文摘The crystal structure of the title compound, C26H27O6P, has been determined by single--crystal X-ray diffraction. The crystal is monoclinic with space groupP21, a=16. 193(l), b=5. 804(1), c=12. 512(2) A, β=93. 187(5)°, V=1174. 13A3, Dc=1. 319 g/cm3, F(000) =492, μ= 13. 52 cm-1, Z= 2, and final R= 0. 042and Rw= 0. 040 for 2349 reflections (I≥3σ(I)). Structure analysis revealed that thepyranose and 4, 6-O-benzylidene ring of the title compound adopts a distorted chair conformation.
基金Supported by the Natural Science Foundation of Jilin Province (No.990337).
文摘This research deals with an investigation of the adsorption of two acids, namely, 5-amino- 2-chlorotoluene-4-sulfonic and chlorhydric acids from their solution onto weakly basic resin. The screening of res-ins, kinetics, and isotherm were studied. The results indicate that the D301R is more appropriate for the removal of acids from solution. The adsorption of acids obeys Langmuir isotherm and the first-order kinetics model. Sorptive affinity of the two acids on D301R was found to be in the order of 5-amino-2-chlorotoluene-4-sulfonic acid> chlorhydric acid. Thermodynamic parameters for the adsorption of acids were calculated and discussed. The maxi-mum removal of acids was observed around 97% and 76% at 25℃ for 5-amino-2-chlorotoluene-4-sulfonic acid and chlorhydric acid , respectively.
