聚苯硫醚副产物浆料的分离及氯化锂的回收研究

聚苯硫醚(PPS)的工业合成采用对二氯苯和硫化钠为原料,N-甲基-2-吡咯烷酮(NMP)为溶剂,氯化锂为助剂,经加压缩聚反应而成.该反应除了获得PPS外,还产生一部分副产物淤浆,有必要对其组成物进行分离回收和资源化利用.本文采用四氢呋喃(THF)为添加剂对这种副产物淤浆进行了分离研究,并对其中的锂盐进行了回收研究.结果表明,采用THF添加剂可以较为容易地将浆料分离为PPS低聚物、NMP以及无机盐,采用有机溶剂提取法可以回收氯化锂,LiCl的回收率可达40%.     

FOX-7的合成和反应机理研究

以2-甲基咪唑为原料合成出1,1-二氨基-2,2-二硝基乙烯(FOX-7)并进行了结构表征,从中间体过滤母液中分离出副产物2-甲基-4(5)-硝基咪唑和仲班酸.直接合成的2-甲基-4(5)-硝基咪唑和仲班酸,最佳收率分别为67.3%和63.3%.首次提出了一个较为完整而详细的合成FOX-7的反应机理,硝基重排成亚硝酸酯是反应的关键步骤.FOX-7主要是通过2-甲基咪唑→2-甲基-4(5)-二氢-5-咪唑啉酮→2-(二硝基亚甲基)-5,5-二硝基-4-咪唑烷二酮→2-(二硝基亚甲基)-4,5-咪唑烷二酮→FOX-7步骤形成.论述了各中间体形成的详细过程并进行了证明,应用该机理解释了硝化过程中主产物和副产物的变化规律.     

喹啉二酮类化合物的合成研究——形成双(二氢喹啉二酮基)甲烷的可能途径

我们曾用2-(3-甲基丁烯-2-基)丙二酸二乙酯与 N-取代芳胺在高温下环合,制备了一系列4-羟基-3-(3-甲基丁烯-2-基)二氢喹啉-2-酮类化合物.在此反应中除得到正常产物外,尚分离到若干副产物,最主要的副产物为3,3′-双(二氢喹啉-2,4-二酮基)甲烷.Young 等人曾对产生这类副产物的机理作过讨论,并提出如下途径:     

新型桥连双锌配合物的合成和结构

合成了二(2-苯并咪唑亚甲基)胺及其副产物[2，5-二(苯并咪唑亚甲基)环二肽 ]的混合配体与助Zn(Ⅱ)的双核超氧化物歧化酶模型化合物．进行了元素分析、紫 外和红外表征；对配合物采用X射线衍射方法测定了晶体结构，并采用G94W程序对 副产物[2，5—二(苯并咪唑亚甲基)环二肽]进行了量子化学计算．     

高效液相色谱分析法测定2-氯-5-三氯甲基吡啶及其类似化合物

采用高效液相色谱法对高效除草剂盖草能的中间体2-氯-5-三氯甲基吡啶(TCMP)及相关化合物的分析条件进行了探讨和优化。使用Zorbax eclipse XDB-C18色谱柱,以乙腈-水(30+70,体积比)为流动相,控制流速1 mL.min-1,采用紫外可变波长检测器,检测波长为240 nm,方法的线性关系良好,相关系数为0.998 4,回收率为99.05%。在实样分析中同时测定了合成TCMP过程中的两个主要副产物2-氯-5-氯甲基吡啶和2-氯-3-三氯甲基吡啶。     

氨甲酰基硅烷与醛反应直接合成α-羟基酰胺

N,N-二甲基氨甲酰基三甲基硅烷与一系列醛反应直接合成了α-羟基酰胺衍生物,收率多数为71%~91%,其结构用元素分析、1H NMR、13C NMR和IR等方法进行了表征.通过研究反应的影响因素发现,醛基相连基团的电子效应是影响反应的重要因素,它既影响反应完成的时间,又影响分离产物的产率.提出了可能的反应机理.该反应具有条件温和、副产物少、产物得率高和后处理简单等优点,是一种有效合成α-羟基酰胺的新方法.     

2-甲基-1,8-萘啶衍生物的甲基溴代反应

报道了2-甲基-1,8-萘啶衍生物的甲基溴化反应,以N-溴代琥珀酰亚胺(NBS)为溴化剂、红外光为引发剂,得到单溴代产物2-溴甲基-1,8-萘啶衍生物及其二溴代副产物2-二溴甲基-1,8-萘啶衍生物,对比了两种不同的反应条件,通过对影响甲基溴化产物产率的反应条件进行优化改进,得到单溴代产物的较优合成条件为：NBS的用量为原料的1.2倍,500 W红外灯为光源,反应时间为2 h。 该反应条件下,单溴代产物的产率可达到54.6%。     

催化合成4, 4'－亚甲基二苯基二氨基甲酸酯反应中生成的副产物研究

确定了4,4'－亚甲基二苯胺与碳酸二甲酯合成4,4'－亚甲基二苯基二氨基甲酸酯反应中生成的副产物的结构，并在此基础上给出了各副产物的形成机理     

对二甲苯氧化产物的高效液相色谱分析

对甲基苯甲酸是重要的化工原料与药物合成中间体。以过渡金属络合物催化剂氧化对二甲苯合成对甲基苯甲酸,粗产品或精制产品中均或多或少地含有深度氧化副产物对苯二甲酸与对羧基苯甲醛等。分析测定这些副产物对控制氧化反应条件与优化粗产品的精制过程、提高目标产物选     

从N-Fmoc-L-α-氨基酸合成同系物N-Fmoc-L-β-氨基酸(Ⅱ)

描述了应用Amdt-Eistert反应合成两种含酰胺基的N-Fmoc-L-β-氨基酸的方法,讨论了在Wolff重排过程中,N-Fmoc-L-β-谷氨酰胺重氮甲基酮和N-Fmoc-L-α-天冬酰胺重氮甲基酮的各自特点及反应过程中生成的副产物.     

Hydrothermal Synthesis and Crystal Structure of Complex Mn2（phen）2（p-MBA）4（H2O）

A novel Mn（Ⅱ） complex Mn2（phen）2（p-MBA）4（H2O） has been hydrothermally synthesized by the reaction of p-methyl benzoic acid （p-MBA） with 1,10-phenanthroline （phen）. Crystal data for this complex： monoclinic, space group C2/c, a= 2.3328（3）, b =1.5549（2）, c = 1.5557（2） nm, β = 121.726（2）°, V= 4.7997（11） nm^3, Mr = 1028.85, Dc = 1.424 g/cm^3, Z = 4, F（000） = 2128, μ（MoKa） = 0.590mm^-1, GOOF = 1.060, R = 0.0333 and wR = 0.0767. In the crystal, each Mn（Ⅱ） ion is coordinated by two nitrogen atoms from one o-phenanthroline molecule, three oxygen atoms from three p-methyl benzoic acids and one oxygen atom from one water molecule, giving a six-coordinate distorted octahedral coordination geometry. Two neighboring Mn（Ⅱ） ions are bridged by two p-methyl benzoic acid groups and one water molecule, and their end positions are respectively coordinated by one 1,10-phenanthroline and one p-methyl benzoic acid molecule, giving a binuclear cage structure, of which the Mn（Ⅱ）…Mn（Ⅱ） distance is 0.3502 nm.     

Synthesis of some substituted difluoronitroacetanilides and their reduction to substituted N-difluoronitroethylanilines

The synthesis of difluoronitroacetanilide and its p-methyl and m-methoxyl derivatives and their reduction by diborane in tetrahydrofuran to the corresponding N-difluoronitroethylanilines is described. Yields on the acetanilides ranged from 13 to 43% and on the anilines from 50 to 64%.     

MCM负载TiO2/Pd复合催化剂的制备、表征和性能

研究了用分子筛MCM多孔材料作载体,制备负载型MCM-TiO2和MCM-TiO2/Pd催化剂。用X-衍射(XRD)对样品进行了表征,在带CCD的T-64000型色散光谱仪上得到了样品的拉曼光谱。比较了样品对对甲基苯酚的光催化降解性能,并探讨了不同温度焙烧样品对对甲基苯酚光降解率的影响。     

p190RhoGAP and Rap-dependent RhoGAP (ARAP3) inactivate RhoA in response to nerve growth factor leading to neurite outgrowth from PC12 cells

Rat pheochromocytoma (PC12) cells have been used to investigate neurite outgrowth. Nerve growth factor (NGF) has been well known to induce neurite outgrowth from PC12 cells. RhoA belongs to Ras-related small GTP-binding proteins, which regulate a variety of cellular processes, including cell morphology alteration, actin dynamics, and cell migration. NGF suppressed GTP-RhoA levels after 12 h in PC12 cells and was consistently required for a long time to induce neurite outgrowth. Constitutively active (CA)-RhoA suppressed neurite outgrowth from PC12 cells in response to NGF, whereas dominant-negative (DN)-RhoA stimulated it, suggesting that RhoA inactivation is essential for neurite outgrowth. Here, we investigated the mechanism of RhoA inactivation. DN-p190RhoGAP abrogated neurite outgrowth, whereas wild-type (WT)-p190RhoGAP and WT-Src synergistically stimulated it along with accelerating RhoA inactivation, suggesting that p190RhoGAP, which can be activated by Src, is a major component in inhibiting RhoA in response to NGF in PC12 cells. Contrary to RhoA, Rap1 was activated by NGF, and DN-Rap1 suppressed neurite outgrowth, suggesting that Rap1 is also essential for neurite outgrowth. RhoA was co-immunoprecipitated with Rap1, suggesting that Rap1 interacts with RhoA. Furthermore, a DN-Rap-dependent RhoGAP (ARAP3) prevented RhoA inactivation, abolishing neurite formation from PC12 cells in response to NGF. These results suggest that NGF activates Rap1, which, in turn, up-regulates ARAP3 leading to RhoA inactivation and neurite outgrowth from PC12 cells. Taken together, p190RhoGAP and ARAP3 seem to be two main factors inhibiting RhoA activity during neurite outgrowth in PC12 cells in response to NGF.     

Study on sensitivity development of 2,3-dihydroxybenzoic acid by capillary zone electrophoresis-amperometric detection with p-methyl benzoate as stacking agent

For its high reactivity and very short half-life, the hydroxyl radical (OH.) in vivo is very difficult to be detected. Usually, it is indirectly quantified by determining 2,3-dihydroxybenzoic acid (2,3-DHBA) and 2,5-dihydroxybenzoic acid (2,5-DHBA), which are the reaction products of salicylic acid (SA) and OH.. Because 2,5-DHBA could be directly formed by the P(450) enzyme, only 2,3-DHBA is regarded as the real biomarker of OH.in biological studies. But the very low concentration of OH* in human bodies makes its determination very difficult and complicated. In this paper, a simple online stacking capillary zone electrophoresis coupled with amperometric detection (CZE-AD) method was explored to improve the detection sensitivity of 2,3-DHBA to reach the requirements in biological analysis. A mixture solution of 12.5 mmol/L Na(2)B(4)O(7)-25 mmol/L NaH(2)PO(4) (pH 7.9) was used as the running buffer and p-methyl benzoate was selected as a suitable stacker. The effects of the concentration, pH value, and injection time of p-methyl benzoate on stacking efficiency were carefully studied. Under the optimum stacking CZE-AD conditions, the detection sensitivity of 2,3-DHBA was improved about 20-fold and its detection limit reached the 10(-9) mol/L level. The experimental results showed that this was a potential method to determine OH* in vivo.     

Fluorine-containing catecholamines. Synthesis of DL-2, 5, 6-trifluorodopa

DL-2,5,6-trifluoro-3,4-dihydroxyphenylalanine (trifluorodopa) hydroiodide has been synthesized from hexafluorobenzene in a six-step procedure. The key step is the methoxylation of p-methyl tetrafluoroanisole. This reaction affords the desired 2,5,6-trifluoro-3,4-dimethoxytoluene, which is separated by preparative glc from 3,5,6-trifluoro-2,4-dimethoxytoluene. Attempts to obtain trifluorodopa by ether cleavage of the appropriately substituted dihydrobenzodioxin have not been successful.     

Phospholipid-assisted synthesis of stable F-containing colloidal particles and their film formation

This letter illustrates for the first time the preparation of p-methyl methacrylate/n-butyl acrylate/heptadecafluorodecyl methacrylate (p-MMA/nBA/FMA) colloidal dispersions containing up to 15% w/w FMA, which is accomplished by the utilization of biologically active phospholipids (PLs) and ionic surfactants. The use of monomer-starved conditions during emulsion polymerization and the utilization of 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC), sodium dodecyl sulfate (SDS), and phosphoric acid bis(tridecafluoro-octyl) ester ammonium salt (FSP) as surfactants, which function as transfer and dispersing agents, facilitate a suitable environment for the polymerization of p-MMA/nBA/FMA colloidal dispersions that exhibit nonspherical particle morphologies. Such nonspherical particles upon coalescence form phase-separated films with unique surface properties.     

Changes in neurite outgrowth but not in cell division induced by low EMF exposure: influence of field strength and culture conditions on responses in rat PC12 pheochromocytoma cells

The effects of low electromagnetic field (EMF) exposure (4.5-15.8 microT, 50 Hz AC) on neurite outgrowth and cell division in rat PC12 pheochromocytoma cells were examined. The study involved two separate experimental series in which culture conditions during exposure to the magnetic fields differed. In series 1 (14 experiments in which culture conditions were not strongly conducive to cell differentiation [15% serum]), exposure to 4.5-8.25 microT for 23 h significantly inhibited neurite outgrowth by 21.5 +/- 1.3% (by Manova, p = 0.003). In contrast, in series 2 (12 experiments in which culture conditions promoted cellular differentiation [4% serum]), exposure to 4.35-8.25 microT for 23 h significantly stimulated neurite outgrowth by 16.9 +/- 1.1% (by Manova, p = 0.009). Thus, in both series, exposure to a narrow range of low EMF has significant, but opposite effects on neurite outgrowth. Exposure to higher fields, 8.25-12.5 microT (series 1) and 8.25-15.8 microT (series 2) had no significant effect on neurite outgrowth. These data, when considered with other reports, suggest that neuronal differentiation can be altered by low level EMF exposure. While this may not be detrimental, it merits further research. At present, the reasons for the significant changes in neurite outgrowth being confined to the same narrow field strength are unclear. As stated above, culture conditions in series 2 were more conducive to cell differentiation than those in series 1. This is reflected in the lower number of cells in control samples in series 2, at the end of the 23-h incubation, than in series 1 (- 16.9 +/- 1.7%, p = 0.003). As the same numbers were plated in both series, the medium used in series 1 allows more of the PC12 cells to divide; this is consistent with some cells reverting to a non-neuronal adrenal chromaffin phenotype [L. Greene, A. Tischler. Establishment of a noradrenergic clonal line of rat adrenal pheochromocytoma cells which respond to nerve growth factor. Proc. Natl. Acad. Sci. U. S. A., 73 (1976) 2424-2426]. Exposure to both ranges of magnetic fields (4.35-8.25 and 8.25-15.8 microT) has no effect on cell division. Thus, there is no evidence in this study that there is a mitogenic effect arising from low EMF exposure.     

Hydrogenation of 2,5-dimethyl-4-phenyl(p-alkylbenzyl) pyridines over metal sulfides

The corresponding substituted piperidines were obtained in yields from 40 to 99.5% by the hydrogenation of 2,5-dimethyl-4-phenylpyridine and 2,5-dimethyl-4-[p-methyl(p-ethyl)benzyl]pyridines in the presence of rhenium, platinum, and palladium sulfides.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 1, pp. 88–90, January, 1972.     

[Co（p—Me—PPA）2（H2O）2]Cl的合成及其催化环己烯氧化反应的研究

环己烯的选择性氧化是一个较难的课题,原冈是环己烯存在两个活性部位易工发生氧化反应：一是烯两基位的氢易被氧化生成环己烯醇和环己烯酮的产物：二是双键易被氧化成环氧化物、环己酮或Ｃ—ＣＸＸ键断裂生成难成酸等。因此人们一直在努力寻找具有高活性,高选择性的催化剂用以催化环己烯的氧化反应［’＊’］。本文合成的Ｋ叶卜＊卜呷Ａ从比０）。厂１,在０。作氧源下ｍ于催化环己烯氧化反应时呈现出较好的转化率和环己烯酮选择性。１【Ｃｏ（Ｐ－Ｍｅ－ＰＰＡ）。（Ｈ。０）。」Ｃ！的合成采ｍ２一毗咙甲酸和ｐ一甲基本胺作原料合成了【…