Synthesis of Important New Pyrrolo[3,4‐c]Pyrazoles and Pyrazolyl‐Pyrrolines from Heterocyclic β‐Ketonitriles

Treatment of heterocyclic β‐ketonitriles 1a,b with hydrazine hydrate and phenylhydrazine afforded the hydrazine derivatives 2a‐d which cyclized in PPA into pyrrolo[3,4‐c]pyrazoles 3a‐d. Reaction of 1a,b with cyanoacetohydrazide furnished the cyanoacetyl pyrrolo[3,4‐c]pyrazoles 4a,b. The hydrazine 2c reacted with β‐diketone and β‐ketoesters to afford pyrazolyl‐pyrrolines 5‐7. Also the later hydrazine reacted with some D‐aldoses and aceteophenone to give the corresponding hydrazones 10‐12 and hydrazine carboxamide derivatives 15a,b respectively.     

稀土在熔盐被覆铬碳化物中的作用研究

研究了熔盐被覆铬碳化物的工艺过程，着重探讨了稀土对Ｔ１２Ａ钢熔盐渗铬的催渗及微合金化作用机理。结果表明，在加入稀土的熔盐中渗中提高渗速３０％－５６％，同时还能提高工件表面的抗氧化和耐腐蚀性能以及工件的使用寿命。     

Antineoplastic anthraquinones. II. Design and synthesis of 1,2-Heteroannelated anthraquinones

Based on the “2-phenyinaphthalene-type” structural pattern hypothesis, a number of heterocycle-fused anthraquinones were designed by taking morindaparvin-A ( 2a ) as the lead structure. The compounds we synthesized and tested for antineoplastic activity include 1,2-alkylenedioxyanthraquinone, naphtho [2,3-f]-quinoxaline-7,12-dione, anthra[1,2-d]imidazole-6,11-dione and naphtho[2,3-f]quinoxaline-7,12-dione derivatives. Most of the synthesized anthraquinones possessed various degrees of anticancer activity. One of these compounds, 2-chloromethyl-1H-anthra[1,2-d]imidazole-6,11-dione ( 4b ), exhibited cytotoxic activity against all tested human carcinoma cell lines.     

碱性溶液中金电极上氧还原中间物研究

应用改进了的旋转全电极上的电势阶跃计时库仑法,分别测定了不同电极电势下氧还原过程中电极吸附中间物和溶解中间物氧化所需的电量,实验证明,在此过程中电极上确有吸附中间物存在,而且是电极电势的函数,但其分子属性尚需进一步鉴别。     

Determination of catecholamines in pheochromocytoma cell (PC-12) culture medium by microdialysis-microbore liquid chromatography

An in vitro microdialysis system was constructed for the measurement of catecholamines in pheochromocytoma cell culture medium. The novel microdialysis device is composed of a petri dish, a dialysis membrane and two transmission tubes. The dialysis membrane is located in the space of a petri dish such that it is immersed in the culture medium. Catecholamines contained in the culture medium diffused into a designed dialysis membrane with sufficient recovery (about 60%). Dialysates were collected by a sampling loop and introduced by an on-line injector to a microbore liquid chromatographic system for analysis of catecholamines. This assay yielded a detection limit of 0.2–0.5 pg/injection with acceptable intra- and inter-assay reproducibilities in 5 μl of dialysates. To evaluate the on-line microdialysis system, PC-12 cells were cultured in a petri dish within an incubator. The baseline concentration of dopamine in PC-12 cell culture medium was about 0.29 ng/ml which was elevated to 2.43 ng/ml after treatment with 0.5 mM potassium cyanide. In conclusion, the present microassay provides for the sensitive, direct measurement of catecholamines in culture medium while minimizing pretreatment procedures for sample preparation.     

Mass spectrometric study of gamma-aryl-alpha,-gamma-diethoxy-alpha, beta-butenolides

Electron impact mass spectra of eight of the title compounds are reported. Abundant fragment ions were produced under electron impact (EI) conditions and, with one exception, the ($?hbox?ArC??equiv$ O) ions were the base peaks. The EI fragmentation mechanisms of two representative compounds were studied with the aid of high-resolution and mass-analyzed ion kinetic energy spectrometry (MIKES) data. The M(+) ions fragment to give both an odd-electron ion and an even-electron fragment ion. Two H-atom rearrangements proceeding via four-membered ring intermediates and three losses of CO through i- and alpha-fragmentations were observed under EI. On comparing fragmentations under EI conditions with those under FAB conditions for two of the compounds, the fragmentation mechanisms were reasonably similar, with additional fragmentations rationalized in terms of the ionization proton being located on the oxygen atom of the beta-ethoxy group.     

Catalysts for the determination of oxygen in organic compounds

Summary Thermal decomposition of metal-organic complexes of nickel, cobalt and iron has given catalysts which are very effective at about 900° for the conversion of carbon dioxide, water and other oxygencontaining sample decomposition products to carbon monoxide in the direct determination of oxygen in organic compounds when using a modified Unterzaucher type apparatus. A copper catalyst similarly prepared required a temperature of 1030° whereas a manganese complex decomposition product was ineffective.

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Katalysatoren zur Sauerstoffbestimmung in organischen Substanzen

Zusammenfassung Durch thermische Zersetzung metallorganischer Komplexe von Ni, Co und Fe erhält man Katalysatoren, die die Umwandlung von CO₂, H₂O und anderen sauerstoffhältigen Zerfallsprodukten zu CO bei etwa 900° C bei der direkten Sauerstoffbestimmung in einer modifizierten Unterzaucher-Apparatur sehr wirksam fördern. Ein ähnlich hergestellter Cu-Katalysator erfordert 1030° C und das Zersetzungsprodukt eines Mn-Komplexes ist unwirksam.

     

Catalytic Adsorptive Stripping Voltammetry of Germanium(IV) in the Presence of Gallic Acid and Vanadium(IV)‐EDTA

A highly sensitive and selective catalytic adsorptive cathodic striping procedure for the determination of trace germanium is presented. The method is based on adsorptive accumulation of the Ge(IV)‐gallic acid (GA) complex onto a hanging mercury drop electrode, followed by reduction of the adsorbed species. The reduction current is enhanced catalytically by addition of vanadium(IV)‐EDTA. The optimal experimental conditions include the use of 0.03 mol/L HClO₄ (pH1.6), 6.0×10^?3 mol/L GA, 3.0×10^?3 mol/L V(IV), 4.0×10^?3 mol/L EDTA, an accumulation potential of ?0.10 V(vs. Ag/AgCl), an accumulation time of 120 s and a differential pulse potential scan mode. The peak current is proportional to the concentration of Ge(IV) over the range of 3.0×10^?11 to 1.0×10^?8 mol/L and the detection limit is 2×10^?11 mol/L for a 120 s adsorption time. The relative standard deviation at 5.0×10^?10 mol/L level is 3.1%. No serious interferences were found. The method was applied to the determination of germanium in ore, mineral water and vegetable samples with satisfactory results.     

磷钼钒杂多酸在苯直接羟化反应中的催化作用——O2活化机理的探讨

磷钼钒杂多酸在有供电子体存在下具有活化氧和使苯直接羟化的催化性能。以抗坏血酸和亚硫酸钠为还原剂的实验表明不同的还原体系吸氧动力学和羟化活性不同。根据氧化还原滴定、循环伏安法、电解还原羟化反应以及光谱实验等测定结果, 对这两个不同体系提出了各自可能的氧的活化机理。认为在以抗坏血酸为还原剂的情况下, 杂多酸阴离子通过三电子传递过程直接络合氧, 氧与阴离子形成中间络合物为控制步骤。在以亚硫酸钠为还原剂的情况下, 供电子体可能先与阴离子络合活化, 直接参与氧的活化过程, 供电子体与阴离子的还原络合为控制步骤。     

利用高炉水淬渣制备(Ca/Y)-α-Sialon陶瓷的组织与性能

以高炉水淬渣合成的Ca-α-Sialon粉体为原料采用无压烧结技术制备了（Ca/Y）-α-Sialon陶瓷。通过用排水法、三点弯曲实验法、金相显微镜法、XRD法等手段研究了（Ca/Y）-α-Sialon陶瓷的烧结致密化过程、材料的力学性能、显微组织、相组成和材料的断裂特征。结果表明,适量的Y2O3促进材料的烧结致密化和提高材料的力学性能,但Y2O3过量（大于10%）时对材料的烧结和力学性能不利。掺杂Y^3＋的（Ca/Y）-α-Sialon呈柱状晶,随着Y2O3含量的增加和烧结温度的提高,（Ca/Y）-α-Sialon呈柱状晶出现粗化和等轴化。含10%Y2O3的材料在1700℃烧结时可获得较高的力学性能。