3-甲基-4-乙氧甲酰-2-环己烯酮合成方法的改进

甲基乙氧羰基环己烯酮;多聚甲醛;3-甲基-4-乙氧甲酰-2-环己烯酮合成方法的改进     

2-甲酰基-3-乙酰基-4-甲基-5-苄氧羰基吡咯的合成

甲酰基乙酰基甲基苄氧羰基吡咯;二甲基乙酰基苄氧羰基吡咯;加成环化;选择性氧化     

3-N-乙酰基-2-取代芳基-5-[5'-甲基-异噁唑-3']-Δ3-1,3,4－噁唑啉类化合物的合成

甲基-异噁唑甲酰肼;3-N-乙酰基-2-取代芳基-5-[5'-甲基-异噁唑-3']-Δ3-1;3;4－噁唑啉类化合物的合成     

催化分子氧氧化合成3-甲基-4-硝基苯甲酸

催化分子氧氧化合成3-甲基-4-硝基苯甲酸;液相氧化;二甲基硝基苯;甲基硝基苯甲酸;合成     

4-乙酰基-2-硝基苯甲醛的简便合成

从4-乙酰基-2-硝基甲苯出发, 经溴化、羟化、氧化以88.5%的总收率制备得到4-乙酰基-2-硝基苯甲醛.     

5-甲基-3-硝基-4-异噁唑甲酰腙的晶体结构、电子光谱、抑菌活性及其量化计算

将3-硝基水杨醛和5-甲基-4-异噁唑甲酰肼于中温混合溶剂热体系中合成了标题化合物5-甲基-3-硝基-4-异噁唑甲酰腙(C12H10O4N4,3),并对其进行了单晶结构解析、紫外、荧光和热重分析等表征.结果表明,晶体属正交晶系,Pna21空间群.晶胞参数:a=1.28783(6)nm,b=1.13108(6)nm,c=0.86535(4)nm,V=1.2605nm3,Z=4.标题物3的水溶液在486nm处呈现一强蓝色荧光发射峰,归属于激发态分子内质子转移电荷发光;标题物3对枯草芽孢杆菌、铜绿脓杆菌、大肠杆菌和金黄色葡萄球菌等都有明显的抑菌活性;分子的静电势图(EPM)再现其具有较强的广谱抗菌活性.     

3-（3-乙酰基-5-芳氧亚甲基-2,3-二氢-1,3,4-噁二唑-2-基）色酮类化合物的合成

3-（3-乙酰基-5-芳氧亚甲基-2;3-二氢-1;3;4-噁二唑-2-基）色酮类化合物的合成;噁二唑啉;色酮;合成     

2-乙氧羰基-3-溴-4-甲基-5-甲酰基-吡咯的合成

2-乙氧羰基-3-溴-4-甲基-5-甲酰基-吡咯的合成;乙氧羰基二甲基吡咯;乙氧羰基溴二甲基吡咯;乙氧羰基溴甲基甲酰基吡咯     

用新方法催化合成6-乙酰基-1-甲基环己烯

室温下用HY沸石取代传统催化剂通过1-甲基环己烯与乙酐的酰基化反应合成了6-乙酰基-1-甲基环己烯，考察了HY沸石的SiO2／Al2O2摩尔比、用量和活化时间以及反应时间对该酰化反应的影响．当1-甲基环己烯／乙酐／HY沸石(SiO2／Al2O3摩尔比=29)=1mmol／10mmol／0．200g、反应温度25℃、反应时间3h时，所得酰化产品的产率为60％，HY沸石能够回收和重新使用，显示出与新鲜催化剂几乎相同的催化活性．     

一种高效的消旋(S)-3-氨甲酰甲基-5-甲基-己酸的方法

3-氨甲酰甲基-5-甲基-己酸经拆分后得到的(R)-构型体是合成抗癫痫药物普瑞巴林(pregabalin, PGB)的关键中间体,余下的对映体(S)-构型体一般经酸化成无手性中心的3-异丁基戊二酸后再通过化学反应使之生成3-氨甲酰甲基-5-甲基-己酸的消旋体以重复利用,该方法步骤较多,费时较长（约40小时）,收率只有29.5%。本文在二甲苯中加热(S)-构型体,使之转化为3-异丁基戊二酰亚胺,后者在氢氧化钠水溶液中经水解得到3-氨甲酰甲基-5-甲基-己酸的消旋体。此方法耗时短（约20小时）且收率高（76.4%）。     

Die Kristallstruktur des W3CoB3 und der dazu isotypen Phasen Mo3CoB3, Mo3NiB3 und W3NiB3

Zusammenfassung Mo₃CoB₃, Mo₃NiB₃, W₃CoB₃ und W₃NiB₃ kristallisieren in einem eigenen Typ (W₃CoB₃-Struktur). Das trigonal prismatische Bauelement [T ₆B]^* ist zu Ketten vereinigt, wobei B₃-Gruppen entstehen. Die Phasen sind vermutlich Bor-reicher als obiger Formel entspricht.

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The crystal structure of W₃CoB₃ and the isotypic phases Mo₃CoB₃, Mo₃NiB₃, and W₃NiB₃

Mo₃CoB₃, Mo₃NiB₃, W₃CoB₃, and W₃NiB₃ were found to possess a new type of crystal structure (W₃CoB₃-structure type). Trigonal prismatic groups [T ₆B]^* are linked together forming chains in such a way that B₃-groups occur. These borides do probably exist with a larger amount of boron as to compared with the formula.

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Synthesis of γγγ-trifluorocarbonyl compounds

γγγ-Trifluorocarbonyl compounds are easily obtained in a good yield by introduction of the 1,1,1-trifluoroethyl moiety (CF₃-CH₂-) on the -methylene group of a ketone.     

γ-Nitro-γ-butyrolacton

γ-Nitro-γ-butyrolactone By oxidation of 3-(1-nitro-2-oxocyclohexyl)propanal ( 1 ) with KMnO₄, besides 3-(1′-nitro-2′-oxocyclohexyl)pripionic acid ( 2 ), the complete hydrolysis product 4-oxononanedioic acid ( 4 ) and the oxidized semi-hydrolysis product 5-(2-nitro-5-oxotetrahydro-2-furyl)pentanoic acid ( 3 ) were formed. The crystalline 3 decomposes at r.t. forming 4 and nitrous gases; its structure was established by X-ray determination.     

Freezing the polarization of CH3NH3PbI3 and CH3NH3PbI3-xClx perovskite films

Thin films of methylammonium lead halides, CH₃NH₃PbI₃ and CH₃NH₃PbI_3-xCl_x, were deposited onto symmetrical microstructured electrode arrays of gold or platinum on Si/SiO₂ wafers. Polarization studies were carried out on perovskite films under vacuum in the dark. For poling, a constant voltage was applied to the samples while the temperature was cycled between 295 K and 4 K. The measured current densities depending on the temperature showed distinct characteristics relating strongly to the crystal phase and the dielectric properties of the perovskite films. Voltage sweeps were carried out at different scan rates at specific temperature intervals after poling. The polarization of the films due to the migration of iodide vacancies in direction of the blocking perovskite/metal interface was frozen almost up to room temperature. Charge carriers were only able to cross the blocking barrier and contribute to the current where the ions have accumulated during poling. All J-V curves showed hysteresis: inverted and regular hysteresis at room temperature and below, respectively. Inverted hysteresis originates from the slow accumulation of ions at the blocking barrier, while regular hysteresis arises from a distortion in the adjacent crystals which will be discussed.     

K3BiSe3, Rb3BiSe3 und Cs3BiSe3 – Substitutionsvarianten des Th3P4-Typs

K₃BiSe₃, Rb₃BiSe₃, and Cs₃BiSe₃ – Derivatives of the Th₃P₄ Structure Type The compounds K₃BiSe₃, Rb₃BiSe₃, and Cs₃BiSe₃ were synthesized by heating mixtures of Bi₂O₃ and the respective alkalicarbonate in a stream of hydrogen saturated by selenium at 850°C. Thin crystals of the compounds appear red in transmitted light. They crystallize isostructural with Na₃AsS₃, space group P2₁3, lattice constants a = 9.771(5) Å, a = 10.161(3) Å, and a = 10.587(5) Å for K₃BiSe₃, Rb₃BiSe₃, and Cs₃BiSe₃, respectively. The Na₃AsS₃ structure type is a derivative of the Th₃P₄ structure type.     

3x-pyrrolizin-3-ones

Condensation of pyrrole-2-dithiocarboxylates with CH acids containing ester groups, in the KOH-DMSO system, was used to prepare previously unknown 1-alkylthio-3H pyrrolizin-3-ones. The latter, treated with secondary amines, are readily converted to the corresponding 1-amino derivatives.     

3-H-pyrrolizin-3-ones

Previously unknown 1-alkylthio-3H-pyrrolizin-3-ones have been obtained by the condensation of pyrrole-2-dithiocarboxylates with CH acids containing ester groupings in the KOH-DMSO system. On treating the products with secondary amines they are readily converted into the corresponding 1-amino derivatives.Irkutsk Branch of the Russian Academy of Sciences, Irkutsk 664033. Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 7, pp. 919–924, July, 1996. Original article submitted May 2, 1996.     

Die Akzeptoreigenschaften von AsCl3, AsBr3, asJ3, SbCl3, SbBr3 und SbJ3

Zusammenfassung Es wurden die Enthalpien der Reaktionen von AsCl₃, AsBr₃, AsJ₃, SbCl₃, SbBr₃ und SbJ₃ mit Tributylphosphat, N,N-Dimethylacetamid und Hexamethylphosphorsäuretriamid bestimmt. Das Verhalten der Addukte bei Gegenwart eines Überschusses der Donoren wird beschrieben.

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Acceptor properties of AsCl₃, AsBr₃, AsI₃, SbCl₃, SbBr₃, and SbI₃

The enthalpies of the reactions of AsCl₃, AsBr₃, AsI₃, SbCl₃, SbBr₃ and SbI₃ with tributylphosphate, N,N-dimethylacetamide and hexamethylphosphoric acid triamide were measured. The behavior of the adducts in the presence of excess donor molecules is described.

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