Asymmetric Synthesis of (-)-1-Trimethylsilyl-ethanol with Immobilized Saccharomyces Cerevisiae Cells in Water/Organic Solvent Diphasic System

Asymmetric synthesis of (-)-1-trimethylsilyl-ethanol with immobilized Saccharomyces cerevisiae cells in water/organic solvent biphasic system was studied. The effects of shake speed, hydrophobicity of organic solvent, volume ratio of water phase to organic phase, pH value of aqueous phase and reaction temperature on the initial reaction rate, maximum yield and enantiomeric excess (ee) of the product were systematically explored. All the above-mentioned factors had significant influence on the reaction. n-Hexane was found to be the best organic solvent for the reaction. The optimum shake speed, volume ratio of water phase to organic phase, pH value and reaction temperature were 150 r.min-1, 1/2, 8 and 30 ℃ respectively, under which the maximum yield and enantiomeric excess of the product were as high as 96.8% and 95.7%, which are 15% and 16% higher than those of the corresponding reaction performed in aqueous phase. To our best knowledge, this is the most satisfactory result obtained.     

郁李仁(R)-醇腈酶高效催化乙酰基三甲基硅烷与丙酮氰醇不对称转氰

Highly efficient asymmetric transcyanation of acetyltrimethylsilane with acetone cyanohydrin in an aqueous/organic biphasic system catalyzed with(R)-oxynitrilase from defatted Prunus Japonica seed meal for the preparation of optically active(R)-2-trimethylsilyl-2-hydroxyl-propionitrile was successfully carried out for the first time.For better understanding of the reaction,various influential variables were examined with respect to the initial reaction rate,the substrate conversion and the product enantiomeric excess(e.e.).Diisopropyl ether was found to be the best organic phase for this reaction among all the organic solvents tested.The optimal concentrations of Prunus Japonica seed meal powder,acetyltrimethylsilane and acetone cyanohydrin,volume ratio of aqueous phase to organic phase,buffer pH value and the reaction temperature were 34. 5 g.L~(-1) and 14 mmol·L~(-1) ,28 mmol.L~(-1) , 13%(by volume),5. 0 and 30℃,respectively,while the initial reaction rate,the substrate conversion and the product enantiomeric excess were 1. 34 mmol.L~(-1) .h~(-1) ,99. 0% and 99. 0%,respectively.The comparative study demonstrated that silicon atom in substrate showed great effect on the reaction and acetyltrimethylsilane was a much better substrate for(R)-hydroxynitrile lyase from Prunus Japonica seed than its carbon analogue 3,3-dimethyl-2-butanone.     

郁李仁（R）-醇腈酶高效催化乙酰基三甲基硅烷与丙酮氰醇不对称转氰

Highly efficient asymmetric transcyanation of acetyltrimethylsilane with acetone cyanohydrin in an aqueous/organic biphasic system catalyzed with （R）-oxynitrilase from defatted Prunus Japonica seed meal for the preparation of optically active （R）-2-trimethylsilyl-2-hydroxyl-propionitrile was successfully carried out for the first time. For better understanding of the reaction, various influential variables were examined with respect to the initial reaction rate, the substrate conversion and the product enantiomeric excess （e.e.）. Diisopropyl ether was found to be the best organic phase for this reaction among all the organic solvents tested. The optimal concentrations of Prunus Japonica seed meal powder, acetyltrimethylsilane and acetone cyanohydrin, volume ratio of aqueous phase to organic phase, buffer pH value and the reaction temperature were 34.5g·L^-1 and 14mmol· L^-1, 28mmol· L^-1, 13% （by volume）, 5.0 and 30℃, respectively, while the initial reaction rate, the substrate conversion and the product enantiomeric excess were 1.34 mmol·L^-1·h^-1, 99.0% and 99.0%, respectively. The comparative study demonstrated that silicon atom in substrate showed great effect on the reaction and acetyltrimethylsilane was a much better substrate for （R）-hydroxynitrile lyase from Prunus Japonica seed than its carbon analogue 3,3-dimethyl-2-butanone.     

Sulfonation of 1,4-diaminoanthraquinone leuco by chlorosulfonic acid:Kinetics and process intensification

The work herein employed a rotating packed bed(RPB) to intensify the sulfonation process of 1,4-diaminoanthraquinone leuco(DL) in an attempt to improve the yield of the product 1,4-diaminoanthra quinone-2-sulfonic acid(DSA). First, the effects of operating conditions in a stirred tank reactor(STR),including stirring speed, chlorosulfonic acid/DL molar ratio(η), solvent/DL mass ratio(ζ), reaction temperature and dropping speed of chlorosulfonic acid, on the yield of DSA were investigated. The yie...     

Enantioselective esterification of (R,S)-2-(4-methylphenyl) propionic acid via Novozym 435: Optimization and application

This paper reports on the resolution of(R,S)-2-(4-methylphenyl) propionic acid(MPPA) enantiomers by enzymatic esterification in organic solvent. Novozym 435(CALB) has the best catalytic performance compared with other lipases. Of the alcohols screened, n-hexanol is the best acyl acceptor and gives the highest enzyme activity and enantioselectivity in n-hexane. Response surface methodology(RSM) was used to evaluate the influence of the factors, such as temperature, enzyme amount, substrate concentration and reaction time on the substrate conversion(c) and enantiomeric excess(ee). The correlation coefficient R~2 for enantiomeric excess and the conversion are 0.9827 and 0.9910, respectively, indicating that can accurately predict the experimental results. By simulation and optimization, the optimal conditions were obtained, involving 600 mmol·L~(-1) MPPA concentration(0.60 mmol), 850 mmol·L~(-1) hexanol concentration(0.85 mmol), 58 mg enzyme amount, 75 ℃ temperature and 4.5 h reaction time, respectively. Under the optimized conditions, the experimental values of conversion and enantiomeric excess were 89.34% and 97.84%, respectively, which are in good agreement with the model predictions.     

有机介质中脂肪酶促动力学拆发外消旋1-三甲基硅乙醇

The enantioselective esterification of racemic 1-trimethylsilylethanol with acids catalyzed by lipase in organic solvent was successfully performed. The influence of some factors on the reaction was investigated. Among the four lipases explored, Candlda rugosa lipase (CRL) showed the highest activity and enantioselectivity. Octanoic acid was the best acyl donor among the eleven acids studied and n-hexane was the most suitable medium for the reaction. The optimum shaking rate and temperature were found to be 150 r-rain-i and 20~(3 to 30~C, respectively.The enantiomeric excess of the remaining (S)-(-)-1-trimethylsilylethanol was 93% when substrate conversion was 53% upon incubation of the reaction mixture at 30~C, 150 r-rain-i for 12 h.     

非均相羰基氧化一步合成碳酸二苯酯的研究(Ⅴ)筛选催化剂及优化合成条件

Pd/LaxPbyMnOz, Pd/C, Pd/molecular sieve and Pd-heteropoly acid catalysts for direct synthesis of diphenyl carbonate (DPC) by heterogeneous catalytic reaction were compared and the results of DPC synthesis indicated that the catalyst Pd/LaxPbyMnOz had higher activity. The Pd/LaxPbyMnOz catalyst and the support was characterized by XRD, SEM and TEM, the main phase was Lao.szPbo.asMnOa and the average diameter could be about 25.4nm. The optimuna conditions for synthesis of DPC with Pd/LasPbyMnOz were determined by orthogonal experiments and the experimental results showed that reaction temperature was the first factor of effect on the selectivity and yield of DPC, and the concentration of O2 in gas phase also had significant effect on selectivity of DPC. The optimum reaction conditions were catalyst/phenol mass ratio l to 50, pressure 4.5MPa, volume concentration of O2 25%, reaction temperature 60℃ and reaction time 4 h. The maximum yield and average selectivity could reach 13% and 97% respectively in the     

三元铁基离子液体-乙醇-水体系的湿法烟气脱硫性能研究(英文)

Fe-based ionic liquid(Fe-IL) was synthesized by mixing FeCl3?6H2O and 1-butyl-3-methylimidazolium chloride [Bmim]Cl in this paper.The phase diagram of a ternary Fe-IL,ethanol and water system was investigated to construct a ternary desulfurization solution for wet flue gas desulfurization.The effects of flow rate and concen-tration of SO2,reaction temperature,pH and Fe-IL fraction in aqueous desulfurization solution on the desulfuriza-tion efficiency were investigated.The results shows that the best composition of ternary desulfurization solution of Fe-IL,ethanol and water is 1︰1.5︰3 by volume ratio,and pH should be controlled at 2.0.Under such conditions,a desulfurization rate greater than 90% could be obtained.The product of sulfuric acid had inhibition effect on the wet desulfurization process.With applying this new ternary desulfurization solution,not only the catalyst Fe-IL can be recycled and reused,but also the product sulfuric acid can be separated directly from the ternary desulfurization system.     

垂直管式反应器中超临界甲醇连续制备生物柴油I:相含率及反应中间产物的轴向分布(英文)

Production of biodiesel with supercritical methanol is a green synthesis process.A study was carried out in a vertical tubular reactor with a length of 3700 mm and a diameter of 20 mm at 275-375°C,15 MPa,and molar ratio of methanol to soybean oil of 40︰1.The phase holdup,intermediate product,yield and axial distribution of methyl ester(ME) were investigated.Methanol and oil were mixed non-uniformly due to the formation of biodiesel and difference in their densities,even when the reaction system was in the supercritical state.From top to bottom,the phase holdup of methanol increased and that of oil decreased.As temperature increased,the concentrations of monoglyceride and diglyceride decreased gradually and the ME yield increased.When the temperature reached 300°C,the critical temperature of the system,the ME yield was 50%.Further increase in temperature led to a sharp in-crease of ME yield.However,at 375°C after 1200 s of reaction time,the decomposition rate of ME was greater than its formation rate,reducing the ME yield.     

Direct extraction of Mo(Ⅵ) from sulfate solution by synergistic extractants in the rotation column

Direct extraction of molybdenum from sulfate solution with synergistic extractants(mixture of D_2EHPA and TBP)was studied in the rotation column. The influence of extractant concentration and initial pH of aqueous phase was studied in the bench scale experiments. The outcomes demonstrated that the synergistic solvent extraction enhances the constancy of the extracted complexes for transfer into the organic phase. In the continuous experiments, the effect of different operating parameters such as speed of agitation, inlet solvent flow rate and inlet aqueous flow rate on the holdup, mean drop size, drop size distribution, slip and characteristic velocities and extraction percentage were examined. Modified correlations were proposed for prediction of hydrodynamic parameters with consideration of reaction extraction condition in the rotation column. Furthermore, these correlations were compared with the experimental data. According to the results, the direct extraction of Mo(Ⅵ) from aqueous solution and sulfuric media with extraction efficiency of 90.4% was obtained at higher rotor speed(240 r·min~(–1) rpm) in this column.     

2-正丁基-4-氯-5-甲酰基咪唑合成新工艺

以戊腈为原料,经加成、取代得到脒（2）,再与乙二醛缩合、脱一分子水得到眯唑啉酮化合物（3）,最后经氯代、氧化后得到2-正丁基-4-氯-5-甲酰基咪唑,收章40．5％。该工艺具有原料易得,反应条件温和,合成路线短,易于工业化生产等特点,是-条新的2-正丁基-4-氯-5-甲酰基咪唑（1）合成路线。     

N-丁基-3-甲酰胺基-4-甲基-6-羟基-2-吡啶酮的HPLC测定

研究了用高效液相色谱测定N－丁基－3－甲酰胺基－4－甲基－6－羟基－2－吡啶酮含量的方法，样品在ODS柱上分离，流动相为含0．2％四丁基氯化铵的甲醇－水体系，流速为1．0mL/min，紫外254nm检测，方法简便，快速，测定的变异系数为0．5％－0．9％。     

2,4,4-三甲基-3-(3-羰基-1-丁烯-1-基)-2-环己烯基-1-肟的合成研究

以环柠檬醛为原料,经过亚硝化、缩合两步反应得到2,4,4-三甲基-3-(3-羰基-1-丁烯-1-基)-2-环己烯基-1-肟,收率达65.1%。并分析了该反应中亚硝化的反应机理。     

1-氨基-4-羟基-蒽醌的合成新方法

以1-氨基-2-溴-4-羟基-蒽醌和乙二醇为原料,在碱作用下脱溴得到1-氨基-4-羟基-蒽醌,收率92．O％。     

2-溴-2-硝基-1,3-二丙二醇的合成

以硝基甲烷和四醛为原料,在碱性条件下经烷基羟基化和溴化两步合成2-溴-2-硝基-1,3-二丙二醇,考虑了烷基羟基化反应,溴化反应温度,时间,对产品收率的影响.收率可达78.6%     

对氯-γ-溴丙苯的合成

提出了对氯－r-溴丙苯的合成方法,以对氯氯为原料制取对氯苄基氯化镁,通过镁过量解决了在四氢呋喃中的偶联问题,提高了格氏试验剂的收率,此格氏试剂与环氧乙烷反应得到氯－r-苯丙醇,然后在三氯甲烷助溶剂作用下,与过量的氢溴酸反应得到对氯－r－溴丙苯,文中优化得出了最佳合成条件,为工业化生产提供了理论依据。     

2—甲基—1—丁烯异构为2—甲基—2—丁烯的研究

异戊烯是抽余碳五的一种馏分，主要由两种同分异构体2—甲基—2—丁烯(2MB2)和2—甲基—1—丁烯(2MB1)组成，其中，2—甲基—2—丁烯含量越高，应用价值越高。本研究提供了一种提高异戊烯中2—甲基—2—丁烯含量的方法，即在催化剂作用下，在一定的温度、压力和空速下，以液相形式将2—甲基—1—丁烯异构为2—甲基—2—丁烯。最佳反应条件为：反应温度25—55℃，反应空速5—20hr^-1，反应压力0．6—0．9MPa。在此条件下，异戊烯中的2—甲基—2—丁烯与2—甲基—1—丁烯的比例由原料中的1—4：1提高到10—13：1。     

3-甲基-4-丁酰氨基-5-氨基苯甲酸甲酯的合成

3-甲基-4-丁酰氨基-5-氨基苯甲酸甲酯是重要的药物中间体。以3-甲基-4-丁酰氨基苯甲酸甲酯为原料，经硝硫混酸硝化、铁粉还原得到目标化合物3-甲基-4-丁酰氨基-5-氨基苯甲酸甲酯，总收率72％。研究了硝硫混酸配比、硝化反应时间、还原反应温度、还原反应时间等因素对产物收率的影响，该工艺具有生产成本低，产品质量稳定，收率高的优点。     

有机颜料中间体N,N′—双乙酰乙酰基2—甲基—5—氯代—1,4—苯二胺的合成

以对氯甲苯为原料,经硝化,还原Ｎ－酰化,水解,乙酰乙酰化反应,制成有机颜料中间体Ｎ,Ｎ′－双乙酰乙酰基－２－甲基－５－氯代－１,４－苯二胺。对影响反应的诸因素进行了讨论。     

2-二乙氨基-6-甲基-4-羟基嘧啶的合成研究

报道了2－二乙氨基－6－甲基－4－羟基嘧啶的合成方法,探讨了各种因素对反应收率的影响,产物总收率和纯度分别大于85．0％和97％。