共查询到20条相似文献,搜索用时 31 毫秒
1.
Emanuel Makrlík Ji?í Dybal Petr Vaňura 《Monatshefte für Chemie / Chemical Monthly》2009,286(1):1289-1292
Abstract From extraction experiments in the two-phase water–nitrobenzene system and γ-activity measurements, the stability constant
of protonated tetraethyl p-tert-butylcalix[4]arene tetraacetate in nitrobenzene saturated with water was determined. By using DFT calculations, the most
probable structure of the tetraethyl p-tert-butylcalix[4]arene tetraacetate·H3O+ complex species was derived.
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2.
Emanuel Makrlík Jiří Dybal Petr Vaňura 《Monatshefte für Chemie / Chemical Monthly》2009,140(3):251-254
Abstract From extraction experiments in the two-phase water–nitrobenzene system and γ-activity measurements, the stability constant
of the valinomycin–lithium complex in nitrobenzene saturated with water was determined. Further, the structure of the resulting
complex was indicated by means of the density functional level of theory (DFT) calculations.
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3.
Marco Rupprich Clemens Decristoforo Barbara Matuszczak 《Monatshefte für Chemie / Chemical Monthly》2009,140(4):405-407
Abstract In contrast to the results presented in a previous report, the direct conversion of alcohols to alkyl fluorides with triphenylphosphine
and potassium fluoride in CCl4/DMF under mild conditions failed.
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4.
Bohumil Proksa Richard Hercek Tibor Liptaj Nada Prónayová 《Monatshefte für Chemie / Chemical Monthly》2009,140(5):485-487
Abstract A new compound was isolated from the reaction mixture after O-demethylation of 6-O-acetyl-10α-acetoxycodeine with boron tribromide. The structure of this compound, 10α-hydroxy-β-isomorphine, was elucidated by spectral data, and its spatial arrangement was deduced from an NOE experiment. Capillary zone
electrophoresis was used for separation of morphine and its 10-hydroxy analogues.
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5.
A. López-Hernández K. Venkatesan H. W. Schmalle Heinz Berke 《Monatshefte für Chemie / Chemical Monthly》2009,140(7):845-857
Abstract Stable paramagnetic Cr(II) and Cr(III) bis(alkynyl) complexes of the type [trans(RC≡C)2Cr(dmpe)2]
n+ (R = Ph, SiMe3, SiEt3, C≡C–SiMe3
n = 0, 1) were prepared and characterised by NMR, cyclic voltammetry, EPR, magnetic measurements, and X-ray single-crystal
diffraction studies.
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6.
M. Dabiri Ali A. Mohammadi Hassan Qaraat 《Monatshefte für Chemie / Chemical Monthly》2009,140(4):401-404
Abstract An efficient and direct procedure for the synthesis of novel spiro[isoindoline-1,2′-quinazoline]-3,4′(3′H)-dione derivatives is described. The process employs a condensation reaction of 2-aminobenzamides and isatins in the presence
of a catalytic amount of KAl(SO4)2.12H2O (alum) in ethanol under reflux.
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7.
Abstract UV–visible spectral observations indicate that the J-aggregation of protonated meso-tetra(4-sulfonatophenyl)porphyrin ([H2TSPP]2+) under acidic conditions is completely inhibited by the π–π counteraction between 1-butyl-pyridinium tetrafluoroborate ([bpy]BF4) and [H2TSPP]2+. The studies also suggest that the intermolecular π–π force is of relative importance for the J-aggregates of [H2TSPP]2+ and the intermolecular electrostatic force for the H-aggregates.
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8.
Zhi-zhong Wang Wei Jiao Guang-yun He Run-hua Lu 《Monatshefte für Chemie / Chemical Monthly》2009,140(1):79-81
Abstract A simple method for the straightforward regioselective synthesis of 2,3-mannoepoxy-β-cyclodextrin, which is a valuable precursor for further functionalization of β-cyclodextrin, is achieved under aqueous conditions without any organic solvents at a moderate yield.
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9.
Rahman Hosseinzadeh Mahmood Tajbakhsh Maryam Mohadjerani Zahra Lasemi 《Monatshefte für Chemie / Chemical Monthly》2009,140(1):57-60
Abstract Ethylenebis(N-methylimidazolium) ditribromide, a stable crystalline solid, is easily prepared by reaction of the corresponding dibromide
salt with bromine in n-hexane. 1,3-Diketones and β-ketoesters can be brominated chemoselectively to the corresponding α-monobrominated products
by using this reagent at 0–5 °C. Under the same reaction conditions, diethyl malonate, ethyl cyanoacetate, and malonitrile
were monobrominated at moderate yield.
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10.
Jolanta Pawłowska Krzysztof K. Krawczyk Krystyna Wojtasiewicz Jan K. Maurin Zbigniew Czarnocki 《Monatshefte für Chemie / Chemical Monthly》2009,140(1):83-86
Abstract (+)-Lortalamine was synthesised using (S)-(−)-α-methylbenzylamine as a chiral auxiliary. The stereochemistry of an intermediate compound was established on the basis
of X-ray crystallography, allowing unambiguous assignment of the absolute configuration.
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11.
Maher F. El-Zohry Thanaa A. Mohamed Essam M. Hussein 《Monatshefte für Chemie / Chemical Monthly》2009,140(3):265-272
Abstract 2-Methylbenzimidazole 1 reacted with 3-dicyanomethylidine-1-ethyl-2-oxoindoline 2 in ethyl acetate to afford 1-amino-2-cyano-3,4-dihydro-1′-ethylspiro{benzimidazo[1,2-a]pyridine-3,3′-indolin}-2′-one 6, which was used as a key intermediate in the synthesis of fused spiropolyheterocyclic derivatives of benzimidazopyridopyrimidine
and/or benzimidazonaphthyridine nucleus incorporating an indoline moiety.
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12.
Ashraf A. Mohamed 《Monatshefte für Chemie / Chemical Monthly》2009,140(1):9-14
Abstract Two simple, sensitive, and selective spectrophotometric methods were developed for determining amodiaquine (AQ) and chloroquine
(CQ) based on their oxidation with potassium iodate and potassium bromate, respectively. The initial rates of oxidation of
AQ and CQ were monitored at 342 and 343 nm, the wavelengths of maximum absorptions of the two drugs. The various experimental
parameters affecting oxidation reactions were thoroughly studied and optimized. Beer’s law was obeyed for 0.2–4.0 and 0.5–5.0 μg cm−3, with correlation coefficients of 0.9999 and 0.9998 (n = 6) and a detection limit (based on the 3S
b
-criterion) of 0.04 and 0.06 μg cm−3 for AQ and CQ. The proposed methods were conveniently applied to determining AQ and CQ in pure and dosage forms.
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13.
Ruta Lazauskaite Maryte Daskeviciene Vytautas Getautis Juozas V. Grazulevicius 《Monatshefte für Chemie / Chemical Monthly》2009,140(5):565-571
Abstract Photoinitiated cationic polymerizations of various epoxy monomers bearing a carbazole moiety, 9-[3-(allyloxy)-2-(oxiran-2-ylmethoxy)propyl]-9H-carbazole, 9-[3-methoxy-2-(oxiran-2-ylmethoxy)propyl]-9H-carbazole, 9-[2-(oxiran-2-ylmethoxy)ethyl]-9H-carbazole, as well as a composition of 3,6-dibromo-9-(oxiran-2-ylmethyl)-9H-carbazole with 3,4-epoxycyclohexylmethyl 3,4-epoxycyclohexane carboxylate were investigated in bulk using triphenyl carbenium
salts having anions such as BF4
−, SnCl5
−, and SbCl6
−. Dark polymerizations of the carbazolyl monomers in the presence of the initiators are studied. These photoinduced polymerization
reactions give oligomers of degree of polymerization 4-22. The effect of the anion of the photoinitiator and polymerization
time on the polymerization reaction is discussed.
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14.
Do-Min Lee Gullapalli Kumaraswamy Kee-In Lee 《Monatshefte für Chemie / Chemical Monthly》2009,140(1):73-78
Abstract Catalytic transfer hydrogenation of α-tosyloxyarylketones mediated by a chiral rhodium complex using an azeotropic mixture
of formic acid/triethylamine afforded the corresponding 1-arylethanediol monotosylates in excellent yield with high enantioselectivity.
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15.
Abstract A classical convergent approach for the synthesis of the anticancer drug imatinib has been substantially improved. Imatinib
was assembled by coupling the amine and carboxylic acid precursors by using N,N′-carbonyldiimidazole (CDI) as a condensing agent. Both intermediates have been synthesized by novel efficient methods.
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16.
Fangfang Dang Xinwei Wang Guoping Han Yahong Yao 《Monatshefte für Chemie / Chemical Monthly》2009,140(6):615-617
Abstract A 3D metal-organic framework, [C6H3CdN2O4]·NH4, was synthesized solvothermally and structurally characterized by single-crystal X-ray structure determination. This compound
crystallizes in the tetragonal system with the space group P42/nmc. The crystal structure presents a 3D framework and open channels, exhibiting guest-coordination sites at channel walls and
strong fluorescent emission.
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17.
Lu Chen Xu-Jiang Huang Yi-Qun Li Mei-Yun Zhou Wen-Jie Zheng 《Monatshefte für Chemie / Chemical Monthly》2009,140(1):45-47
Abstract A simple, clean, and environmentally benign three-component process to the synthesis of 2-amino-4H-chromenes using N,N-dimethylaminoethylbenzyldimethylammonium chloride, [PhCH2Me2N+CH2CH2NMe2]Cl−, as an efficient catalyst under solvent-free condition is described. A wide range of aromatic aldehydes easily undergo condensations
with α-naphthol and malononitrile under solvent-free condition to afford the desired products of good purity in excellent
yields. Taking into account environmental and economical considerations, the protocol presented here has the merits of environmentally
benign, simple operation, convenient work-up and good yields. Furthermore, the catalyst can be easily recovered and reused
for at least five cycles without losing its activities.
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18.
Svetlana Marković Sonja Stanković Slavko Radenković Ivan Gutman 《Monatshefte für Chemie / Chemical Monthly》2009,140(2):153-156
Abstract Two mechanisms for the isomerization of cyclopenta[fg]aceanthrylene to acefluoranthene were revealed. The first pathway occurs via a cyclobutyl intermediate, whereas the second
pathway involves a transition state that contains an sp
3-hybridized carbon atom. Both patterns show that the Stone-Wales rearrangement requires extremely high activation energy and
indicate that the isomerization process can occur only under a drastic temperature regime.
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19.
Hitoshi Shirase Yukie Mori Yutaka Fukuda Masanobu Uchiyama 《Monatshefte für Chemie / Chemical Monthly》2009,140(7):801-805
Abstract Bis[N-(1-pyrenylmethyl)salicylideneaminato]zinc(II) emits intense fluorescence on excitation of the pyrenyl group. This fluorescence
originates from the excited state of the salicylideneamine moiety, indicating that efficient intramolecular energy transfer
takes place. The occurrence of such efficient energy transfer is accounted for by significant spectral overlap between the
emission from the S1 state of the pyrenyl group and the absorption of the salicylideneamine–zinc complex.
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20.
Synthesis of 5-spirocyclohexyl-2,4-dithiohydantoin derivatives: a potential anti-leishmaniasis agent
Abdel-Sattar S. Hamad Elgazwy Saad R. Atta-Allha Sherif M. A. S. Keshk 《Monatshefte für Chemie / Chemical Monthly》2009,140(2):243-249
Abstract A series of spiro-dithiohydantoins were synthesized by heating a mixture of 5-spirocyclohexyl-2,4-dithiohydantoin potassium
salt and 3-chloropropanoyl chloride. These compounds were synthesized and evaluated for their activity against five Leishmanial strains in the promastigote stage in vitro. Seventy-two hours inoculation of a variety of products gave an IC
100
and average IC
50 values of 1.25 and 0.376 mg/cm3 against all Leishmanial strains tested.
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