Search results for "Dike"
showing 10 items of 88 documents
Oligomere aus gleichsinnig angeordneten Chalkon-Bausteinen
1999
The cross-conjugated oligomers 1a–d, which contain up to eight alternately arranged chalcone building blocks, were prepared by stereoselective condensation reactions of formyl and acetyl components. The synthetic sequence started with 1,4-dibromo-2,5-dipropoxybenzene (2). Bouveault reactions with DMF and DMA yielded the aldehydes 3 and 6 and the ketones 7 and 10. After the protection of the carbonyl group (3 4 and 7 8), a further Bouveault reaction led to monoprotected dialdehyd 5 and diketone 9, respectively. Repetitive condensation reactions starting with the acetophenone derivative 11 and 5 furnished the aldehyde 12, the ketone 13 and the aldehyde 14. In the final step the target compoun…
New structural motifs in Mn cluster chemistry from the ketone/gem-diol and bis(gem-diol) forms of 2,6-di-(2-pyridylcarbonyl)pyridine: {MnII4MnIII2} a…
2016
The employment of the tripyridyl/diketone ligand 2,6-di-(2-pyridylcarbonyl)pyridine [(py)CO(py)CO(py)], in conjunction with azides (N3−), in Mn cluster chemistry has afforded the mixed-valence (II/III) complexes [MnII4MnIII2(N3)6Cl4(L1)2(DMF)4] (1) and [MnII4MnIII6O2(N3)12(L1)2(L2H)2(DMF)6] (2) in good yields. The resulting ligands L12− and L2H3− are the dianion and trianion of the ketone/gem-diol (L1H2) and bis(gem-diol) (L2H4) forms of (py)CO(py)CO(py), respectively, as derived from the metal-assisted hydrolysis of the parent dicarbonyl organic compound. Under the same synthetic conditions (i.e., reaction solvents, temperature and stirring time), the chemical identity of the two complexes…
A new synthetic entry into the tricyclo[3.3.0.03,7] octane skeleton
1987
Abstract A short synthesis of dimethyl tricyclo[3.3.0.03,7] octane-1,5-dicarboxylate, 13 , and its 3,7-dimethyl-derivative, 14 , by iodine oxidation of the bis-enolate derived from the corresponding dimethyl cis -bicyclo[3.3.0] octane-3,7-dicarboxylate, 11 or 12 , is described.
2-(4-Toluidino)pyrimidine
1984
Aus der Kondensation von 4-Tolylguanidin (1) mil den β-Diketonen 2a-g gehen die 2-(4-Toluidino)pyrimidine 3a-g hervor, unter denen sich Vertreter mit antidiabetischer und antimykotischer Wirksamkeit befinden. Antidiabetic Agents, II: 2-(4-Toluidino)pyrimidines Condensations of 4-tolylguanidine (1) with the β-diketones 2a-g yield the 2-(4-toluidino)pyrimidines 3a-g which comprise compounds exhibiting antidiabetic and antimycotic activities.
Antimykotische wirkstoffe. XX . Fluorierte 2-(4-toluidino)pyrimidine
1985
Aus der Kondensation von 4-Tolylguanidin (1) mit den β-Diketonen 2a-f gehen die fluorierten 2-(4-Toluidino)pyrimidine 3a-f hervor. Strukturtyp 3 zeichnet sich durch antimykotische Wirkung aus. Condensation of 4-tolylguanidine (1) with the β-diketones 2a-f yields the fluorinated 2-(4-toluidino)pyrimidines 3a-f. Structures of type 3 exhibit antimycotic activity.
Antimykotische wirkstoffe. XIX. 4,6-Disubstituierte 2-(cyanamino)pyrimidine
1985
Aus der Umsetzung von Dicyandiamid (1) mit β-Diketonen (2a-c) gehen die 2-Cyanaminopyrimidine (3a-c) hervor. Strukturtyp 3 wird durch spektroskopische Daten gestutzt, wahrend gleichzeitig eine 1-Cyan-2-imino-struktur (4) ausgeschlossen wird. Verbindung 3a zeigt fungistatische und nematizide Wirkungen. The reaction of city dicyandiamide (1) with β-diketones 2a-c leads to 2-(cyanoamino)pyrimidines 3a-c. Structure type 3 is supported by spectroscopic data, while at the same time a 1-cyano-2-imino structure (4) is excluded. Compound 3a exhibits fungistatic and nematicidal activity.
Verbindungen mit potentiell positiv inotroper Wirkung, 2. Mitt. Synthese von 3,4-Dihydro-2-[(3-oxo-1-cyclopenten-1-yl)amino]-1(2H)-phenanthron und 3-…
1984
Die Darstellung der Titelverbindungen aus 1,3-Cyclopentandion und 2-Amino-3,4-dihydro-1(2H)-phenanthron bzw. 2-Amino-1,2,3,4-tetrahydro-1-phenanthrol wird beschrieben. Compounds with Potentially Positive Inotropic Activity, II: Synthesis of 3,4-Dihydro-2-[(3-oxo-1-cyclopenten-1-yl)amino]-1(2H)-phenanthrone and 3-(1,2,3,4-Tetrahydro-1-hydroxy-2-phenanthrylamino)-2-cyclopentenone The synthesis of the title compounds from 1,3-cyclopentanedione and 2-amino-3,4-dihydro-1(2H)-phenanthrone and 2-amino-1,2,3,4-tetrahydro-1-phenanthrole is described.
VAR modeļu un kointegrācijas analīzes pielietojums zelta cenas analīzē
2017
Darbs tiek veltīts kointegrācijai un kļūdas korekcijas modelim. Darbā dots ieskats par vienības saknes testiem, vektoru autoregresijas vienādojumiem, kointegrāciju, kļūdu korekciju modeļiem. Metodes tika pielietotas pētot sakarības starp tādiem valūtu pāriem kā zelts pret ASV dolāru (XAU/USD) un Šveices franks pret ASV dolāru (CHF/USD). Ar Engla-Greinžera un Johansena metodēm parādīts, ka periodā no 2011. gada maija līdz 2016. gada decembrim pastāv kointegrācija starp iepriekš minētajiem instrumentiem.
Near-infrared emissive bacteriochlorin-diketopyrrolopyrrole triads: Synthesis and photophysical properties
2019
International audience; The synthesis of unprecedented energy transfer triads containing a near-infrared (NIR) emissive bacteriochlorin subunit and two diketopyrrolopyrrole (DPP) moieties linked to each other via ethynyl or zero-carbon spacers is presented. Their optical and fluorescence properties were determined in CHCl3 and toluene. These photophysical measurements highlight the ability of DPP scaffold to act as an effective energy donor, which once excited in the range 450-550 nm resulting nearly exclusively NIR emission of hydroporphyrin (ETE > 96%). Since DPP dyes are valuable structurally tunable fluorophores that may be used in the construction of high-performance multicomponent pho…
Dikerogammarus villosus (Crustacea : Amphipoda): another invasive species in Lake Geneva
2004
According to field observations performed in 2002 and 2003, the amphipod species Dikerogammarus villosus (Sowinsky, 1894) is now well established in Lake Geneva. The author predicts that this and future invasions by D. villosus will have serious effects on freshwater ecosystems.