Studies of benzyl hydroxamic acid/calcium lignosulphonate addition order in the flotation separation of smithsonite from calcite

Flotation separation of smithsonite from calcite is difficult due to their similar surface properties.In the present study,a reagent scheme of depressant calcium lignosulphonate(CLS) and collector benzyl hydroxamic acid(BHA) was introduced in the flotation of smithsonite from calcite.Microflotation tests revealed that the efficient flotation of smithsonite from calcite could only be obtained with the addition order of BHA before CLS,which was opposite to the widely-used order that adding depressant prior to the collector.The zeta potential measurements indicated that BHA selectively adsorbed onto smithsonite surface,then not allowed the CLS adsorption onto the smithsonite surface rather than calcite surface because of the steric hindrance,thereby the smithsonite surface remained hydrophobic while calcite surface became more hydrophilic after the addition of CLS.As a result,the calcite flotation was completely depressed while the smithsonite flotation recovery was still in high value,leading to the optimal flotation separation performance.

SYNERGISM OF WOLFRAMITE FLOTATION WITH BENZYL ARSONIC ACID AND SODIUM BUTYL XANTHATE

Wolframite notation with benzyl arsonic acid and sodium butyl xanthate is studied,at first.It shows the efficiency of mineral processig is good when the two agents are added together.Then the synergism of sodium butyl xanthate and benzyl arsonic acid is studied also by HPLC.

A SYNTHESIS OF TETRAMETHYL ETHER OFROSMARINIC ACID BENZYL ESTER

A rosmarinic acid derivative, tetramethyl ether of rosmarinic acid benzyl ester, was synthesized. This is the first report of building this structural skeleton.

Synthesis of Pharmaceutical Intermediates by Toluene Benzylation over Heteropoly Acids on Different Support

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.

The Synthesis of Hexamethyl Ether of Salvianolic Acid A Benzyl Ester

A salvianolic acid A derivative, hexamethyl ether of salvianolic acid A benzyl ester, was synthesized in fourteen steps. The overall yield was 3.4 parts per thousand. The compound was identified by (1)HNMR and MS. This is the first report of building this structural skeleton.

SYNTHESIS OF 3-BENZYL-GLYCERIC ACID:A KEY INTERMEDIATE OF A NOVEL CYCLIC ESTER MONOMER

A route was proposed to synthesize 3-benzyl-glyceric acid (3-BGA) as an important intermediate for the synthesis of a novel six-membered cyclic ester monomer-3-benzyloxymethyl-1,4-dioxane-2,5-dione (3-BMG). According to this route, 3-BGA was obtained from ring-opening reaction of benzyl alcohol with methyl glycidate, which was prepared from the epoxidation of methyl acrylate using sodium hypochlorite as the oxidant.

Optical 2-benzyl-5-hydroxy-4-oxopentanoic acids against carboxypeptidase A:Synthesis,kinetic evaluation and X-ray crystallographic study

2-Benzyl-5-hydroxy-4-oxopentanoic acid 1 and its enantiomers were designed,synthesized and assayed for inhibitory activity against carboxypeptidase A(CPA,EC 3.4.17.1).To verify the role of the terminal hydroxyl group in 1 binding to CPA,2-benzyl-5- benzyloxy-4-oxopentanoic acid 2 was also synthesized and evaluated.The inhibition constants show that both L-1 and D-1 were shown to have strong binding affinity with L-1 being more potent than its enantiomer by 165-fold.On the other hand,the inhibition constant ...

Possibility of the Benzoic Acids Formation by Oxidation of Benzyl Chlorides in the Sand

Seeking the possibility of the formation of benzoic acids from benzyl halides in natural soil, a model oxidation reaction of the halides was carried out in the presence of water and soil in an open air under UV light irradiation. Addition of TiO2 to soil raised the yield of the acid, implying such a metal oxide plays a real catalytic role in this oxidation. By these supplementary experiments, one of the possibilities for the formation of benzoic acids in natural soil from benzyl chlorides was supported.

Kinetics of Reaction of Bromo-epoxy Resin with Oleic Acid catalyzed by Dimethyl benzyl amine

The kinetics of reaction of bromo-epoxy resin with oleic acid in the presence of dimethylbenzylamine catalyst was studied. The reaction is a zero order reaction with respect to oleic acid, first order with respect to epoxy group and 0. 74 order with respect to dimethylbenzylamine. The reaction rate constants at various temperatures and activation energy were determined. The mechanism of this reaction was discussed. Keywords Tetrabromobisphenol-A, Bromo-epoxy resin, Oleic acid kinetics, Reaction mechanism

由苯甲醇合成苯甲酸乙酯综合制备实验的课程思政设计

将苯甲酸合成与苯甲酸乙酯制备两个经典实验改造为综合实验,并以改进合成过程实现绿色、高效转化为案例,引导学生通过查阅文献,综合分析合成过程,指出原合成方法存在的问题和不足,提出改进的建议,在此过程中,引导学生将法律法规、实验规范、学科伦理、绿色理念、环保和可持续发展理念等融入实验的设计和实施全过程,使学生在受到基本操作训练的同时得到素质的全面提升。

强化苄基胂酸浮选细粒锡石的研究

砷(As)作为硫化矿中共伴生的主要有毒有害元素之一,选矿过程中主要以毒砂的形式存在于选矿产品中,经过冶炼系统处理后生成各类含砷物料,将这些含砷物料产品化是冶炼系统砷开路的有效途径,苄基胂酸就是砷开路的主要产品之一,主要用作浮选捕收剂,但因其捕收性较差,在细粒锡石浮选中逐渐被浮选性能更好的羟肟酸类药剂替代。为了进一步提高苄基胂酸对锡石的浮选效果,针对苄基胂酸浮选低品位细粒锡石进行了选矿试验研究。通过单矿物浮选、吸附量测定和红外光谱分析等机理研究,查明了其对锡石的浮选捕收作用较差是苄基胂酸单一作用吸附比例较低、脉石矿物消耗了pH调整剂中的氢离子及脉石矿物直接影响了苄基胂酸在锡石矿物表面的吸附导致的。在此基础上进行了强化苄基胂酸捕收性的研究,找到了两种能明显提高苄基胂酸在锡石表面化学吸附作用效果的活化剂A和B。通过优化苄基胂酸、pH值调整剂、活化剂、抑制剂组合及用量,在给矿含锡0.54%的情况下,使用苄基胂酸+活化剂B的组合药剂,获得了锡精矿品位7.864%、作业回收率82.19%的技术指标,在浮选作业回收率相当的条件下,较生产上使用的羟肟酸类药剂精矿品位提高了1.867个百分点。试验结果为苄基胂酸浮选同类细粒锡石提供了参考依据,为冶炼系统砷的开路提供了技术支撑。

HPLC法测定硫酸阿托品滴眼液中4种常用抑菌剂的含量

目的建立反向高效液相色谱法同时测定硫酸阿托品滴眼液中4种常用抑菌剂(4-羟基苯甲酸、苯甲酸、苯甲醇、山梨酸)的含量。方法应用RP-HPLC等度洗脱法,采用C_(18)色谱柱(250 mm×4.6 mm,5μm),以0.05 mol·L^(-1)磷酸二氢钾溶液(含0.0025 mol·L^(-1)庚烷磺酸钠)-乙腈(84∶16)(用三乙胺调节pH值至5.0)为流动相,检测波长为225 nm,流速为1.0 mL·min^(-1),柱温30℃。结果在该色谱条件下,主成分峰与各抑菌剂完全分离,滴眼液中基质无干扰;方法重复性良好、稳定性良好;4种抑菌剂在各自浓度范围内具有良好的线性关系。结论本法专属性、重复性良好,结果稳定,可用于硫酸阿托品滴眼液中四种常用抑菌剂含量的检测。

苯甲·嘧菌酯与水溶肥料混合使用全程防治杨梅白腐病为主的综合病害效果示范

[目的]筛选出更好的药剂组合供杨梅生产选择使用。[方法]选择32.5%苯甲·嘧菌酯SC与11%含氨基酸水溶肥料混合使用进行以杨梅白腐病为主的综合病害全程防治效果示范。[结果]该组合对杨梅白腐病为主的综合病害有较好的预防与控制作用,在杨梅谢花后、幼果-硬核期和转色期连续用药3次后,对杨梅白腐病的防效达90.61%,极显著优于农户自防区,同时对杨梅褐斑病、炭疽病等其他病害的综合效果也比较理想,且安全性好。[结论]该研究结果为进一步提高杨梅产量和品质、保证食用安全、促进杨梅产业健康可持续发展奠定了科学基础。

The Role of Vanadia for the Selective Oxidation of Benzyl Alcohol over Heteropolymolybdate Supported on Alumina

A series of 12-molybdophosphoric acid (MPA) supported on V2O5 dispersed γ-Al2O3 catalysts with different vanadia loadings were prepared by impregnation and characterized by N2 adsorption-desorption, X-ray diffraction, temperature-programmed reduction, in situ laser Raman spectroscopy, UV-Vis diffused reflectance spectroscopy, scanning electron microscopy, and temperature-programmed desorption of NH3 techniques. Their catalytic activities were evaluated for the vapor phase aerobic oxidation of benzyl alcohol. The catalysts exhibited high catalytic activity and the conversion of benzyl alcohol depended on the vanadia content while the catalyst with 15 wt% V2O5 content showed optimum activity. The characterization results suggest the presence of well-dispersed V2O5 and partially disintegrated Keggin ions of MPA on the support. In situ Raman studies showed a reduced Mo(IV) species when the catalysts were calcined at high temperatures. The high oxidation activity of the catalysts is related to the synergistic effect between MPA and V2O5.

Formation of Benzyl Oxazole, A Competitive Path with the Classical Bishler-Napieralski Reaction

Several aromatic ring-substituted N-acetyl-phenylalanine methyl esters were treated with POCl3 in refluxing benzene, which is the typical condition of B-N reaction. It was found that the normal B-N product 3, 4-dihydroisoquinoline-3-carboxylic acid methyl ester and/or 5-benzyl-2-methyl-4-methoxy oxazole could be obtained. The result depended mainly upon the electron-donating property of the substitutes on the benzene ring. Strong electron-donating groups located at para- or ortho- to the cyclization site will facilitate the formation of the normal B-N product 2. On the other hand, the absence or weak electron-donating groups tended to yield the oxazole product 3. It was established that the formation of benzyl oxazole is the competitive path with the B-N reaction. In this article, an explanation was given based on the mechanism of Bishler-Napieralski reaction.

Synthesis of a Novel UV-Curable Diluent Benzyl Glycidyl Ether Acrylate and Its Application

A novel UV-curable diluent benzyl glycidyl ether acrylate(BGEA) was synthesized by utilizing benzyl glycidyl ether(BGE) and acrylic acid(AA) as starting materials,N,N-dimethylbenzylamine as catalyst and p-hydroxyanisole as inhibitor.The optimum synthetic conditions were that the concentration of N,N-dimethylbenzylamine was 0.90% of reactants by weight,the concentration of p-hydroxyanisole was 0.20% of reactants by weight,the reaction temperature was 90-100℃,and the molar ratio of BGE to AA was 1.00:1.10.The experiment shows that BGEA is a kind of good diluent.The mechanical properties of the UV-cured films with BGEA as diluent to prepare UV-curing coating were superior to that of the UV-cured films with butyl acrylate as diluent to prepare UV-curing coating.

定量核磁共振氢谱法测定苄基喹啉季铵盐产品中二聚体的含量

目的苄基喹啉季铵盐(BQC)是一种常用的酸化缓蚀剂,其合成中的副产物苄基喹啉季铵盐二聚体(BQD)被发现对金属腐蚀具有更高效的缓蚀作用。为了明确合成产物中BQD的有效含量,建立了测定BQD含量的定量核磁共振氢谱法。方法通过合成并提纯得到了BQD,使用元素分析、质谱、核磁、红外等手段对其结构进行表征;以氘代氯仿作溶剂,选择化学位移在δ12附近的BQD单峰和化学位移在δ5附近的内标物二溴甲烷的单峰作为定量峰,根据两峰的面积之比,计算得到产物中BQD的有效含量。结果合成产物中BQD质量分数为11.6%,与加入BQD纯品的比对实验结论基本一致。结论建立的核磁共振氢谱内标法是一种简便、快捷、结果可靠的BQD含量检测方法。

连续条件下氨基酸的N-苄基化反应研究

以氨基酸、苯甲醛、氢氧化钠、硼氢化钠为原料合成了一系列N-苄基氨基酸类化合物,并选取典型天然氨基酸进行连续N-苄基化反应,考察了缩合反应中苯甲醛摩尔分数、反应温度、停留时间等因素对反应的影响;以及还原反应中硼氢化钠摩尔分数、反应温度、停留时间等因素对反应的影响。对典型案例进行连续和间歇反应结果的对比,结果表明,连续法能大大缩短反应时间、简化操作、提高装备效率与收率,该研究为氨基酸的连续N-苄基化生产应用奠定了理论基础。

4种测定苯甲醇、苯甲醛、苯甲酸的高效液相色谱法的比较研究

本文比较研究了4种高效液相色谱法测定混合物中苯甲醇、苯甲醛、苯甲酸的含量。通过比较甲醇与水、乙腈与水、乙腈与甲醇、乙腈与甲酸等流动相,发现流动相为乙腈与甲酸(0.02%)溶液的分离分析效果最佳。优化后的色谱条件为:流动相,V乙腈∶V0.02%甲酸=40:60;检测波长,250 nm;柱温,35℃;流速,1 mL/min;进样量,10μL。三种物质标准曲线的R值分别为R苯甲醇=0.999 8、R苯甲醛=0.999 7、R苯甲酸=0.999 8。

改性ZSM-5分子筛及其催化苯甲醇烷基化反应

采用酸碱改性对ZSM-5分子筛进行了改性,通过XRD、SEM、N2吸-脱附和NH3-TPD等手段对处理前后的样品进行了表征,并研究改性分子筛催化剂的苯甲醇烷基化催化性能。结果表明:适宜的酸碱改性浓度分别为0.1 mol/L和0.3 mol/L,通过碱改性,可以脱除分子筛部分骨架硅,再由酸液洗涤,可去除催化剂表面的附着物,引入一定量的介孔,比表面积增大,暴露出更多的活性位。与改性前相比,介孔体积由0.10 m3/g提高至0.47 m^(3)/g,比表面积由385 m^(2)/g增至452 m^(2)/g,酸量基本保持不变;在温度460℃,总质量空速2.0 h-1,苯与甲醇摩尔比1:1,压力0.5 MPa(H2)时,最优催化剂可连续运行2 016 h,苯转化率最大为63.31%,甲苯和二甲苯选择性最大为95.71%,对二甲苯选择性为26.89%,苯甲醇烷基化催化性能和稳定性能良好。