Search results for "Diketone"

Synthesis and Antitumor Properties of 2,5-Bis(3'-indolyl) thiophenes: Analogues of Marine Alkaloid Nortopsentin

2007

A series of 11 bis-indolylthiophenes of formula I were obtained by cyclization of bis-indole 1,4-diketones using Lawesson''s reagent. Derivs. I (R = OMe, R1 = SO2Ph), I (R = OMe, R1 = Me), I (R = Cl, R1 = Me), and I (R = OMe, R1 = H) were selected to be evaluated in the full panel of about 60 human tumor cell lines derived from nine human cancer cell types and showed antiproliferative activity generally in the micromolar range. The most sensitive cell lines were: CCRF-CEM, MOLT-4, HL60 (TB), and RPMI-8226 of the leukemia subpanel, HT29 and HCC-2998 cell lines of the colon sub-panel, NCI-H522 of the non-small cell lung cancer sub-panel, LOX IMVI of the melanoma sub-panel, and UO-31 of the re…

Lack of nucleophilic addition in the isoxazole and pyrazole diketone modified analogs of curcumin; implications for their antitumor and chemosensitiz…

2009

Curcumin (CUR) can be considered as a good lead compound for the design of new anticancer drugs. Further, structure-activity relationship studies may clarify the importance of the redox activities in the antitumor effects of the drug. We have elaborated the alpha,beta-unsaturated 1,3-diketone moiety of CUR into the isoxazole (ISO) and pyrazole (PYR) derivatives. These derivatives should be much less prone to nucleophilic addition than CUR and benzyl mercaptan addition analyses showed that indeed they do not form isolable conjugated products. When compared with CUR, ISO and PYR exhibited increased cell growth inhibitory and pro-apoptotic effects in liver cancer HA22T/VGH cells as well as in …

The synthesis of fluorinated heteroaromatic compounds. Part 2. Five-membered rings with two heteroatoms. A review

2007

Herbizide, 3. Mitt. Synthese von 4,6-Dialkyl-2-cyanaminopyrimidinen und Untersuchungen ihrer Struktur durch13C-NMR-Spektroskopie

1985

Die Kondensation von Dicyandiamid (1) mit den β-Diketonen 2a–c fuhrt zu den 2,4-unsymmetrisch substituierten 2-Cyanaminopyrimidinen 3a–c, fur deren Struktur sich aus den13C-NMR-spektroskopischen Untersuchungen das Vorliegen eines Gleichgewichts mit den tautomeren Formen 7 und 8 der 2-Cyaniminopyrimidine ableitet. Das 2-Cyanamino-4,6-diethylpyrimidin hat sich als herbizid wirksam erwiesen. Herbicides, III: Synthesis of 4,6-Dialkyl-2-(cyanoamino)pyrimidines and Investigations of Their Structures by 13C-NMR Spectroscopy Condensation of dicyandiamide (1) with the β-diketones 2a–c leads to the 2,4-unsymmetrically substituted 2-(cyanoamino)pyrimidines 3a–c. According to investigations by 13C-NMR …

Electron paramagnetic resonance, ENDOR and TRIPLE resonance study of some 9,10-anthraquinone radicals in solution

1992

EPR, ENDOR and TRIPLE resonance spectra were recorded for 1,8-dihydroxy-3-methyl-9,10-anthraquinone and 9,10-anthraquinone-2-carboxylic acid anion radicals and the 9,10-anthraquinol-2-carboxylic acid cation radical. EPR spectra were recorded for the 5,8-dideuterio-1,4-dideuterioxy-9,10-anthraquinone anion radical, the 6,7-dideuterio-1,4-dideuterioxy-9,10-anthraquinone anion radical and the 1,4-dihydroxy-9,10-anthraquinol cation radical. The coupling contants of the 1,4-dihydroxy-9,10-anthraquinone anion radical were assigned by deuteriation.

Heterobimetallic single-source precursors for MOCVD. Synthesis and characterization of volatile mixed ligand complexes of lanthanides, barium and mag…

1999

Several heterobimetallic complexes of general formula [(M 1 Q) m M 2 (dik) n ], where (M 1 Q) is Cu(salen) or Ni(salen) and M 2 (dik) n is a lanthanide tris(β-diketonate) or an alkali-earth element bis(β-diketonate) with more or less fluorinated diketonato(-) ligands, have been prepared and structurally characterized. Some of them were submitted to thermal and mass spectrometry analyses, and to isothermal vacuum sublimation tests, in view of their potential use as MOCVD single-source precursors for the deposition of heterobimetallic materials. The study stresses upon the influence of the nature of the diketone. of the M 2 cation, and of chemical modification of the salen ligand on the therm…

Neue chemotherapeutisch-aktive 4-trifluormethylpyrimidine

1993

Abstract Condensation of N -(2-hydroxyethyl)- N -methylguanidine sulfate with various β-diketonesbearing 1,1,1-trifluoromethyl substituents leads to 2-[ N -(2-hydroxyethyl)-methylamino]-4-trifluoromethylpyrimidine derivatives. These compounds exhibit antimycotic, trichomonazide and anti-HIV properties.

The reduction mechanism of the CO group.

2001

A detailed study of the electrochemical reduction of benzil in aqueous medium between H0=−5 and pH 11 is presented. A global 2e−, 3H+ or 2e−, 2H+ surface reaction leads to cis and trans endiols. Analysis, using the theory of the square schemes with protonations at equilibrium, shows that in all the pH range the reaction is controlled by the second electron uptake, the paths being successively H+, e− and e−, H+. The electrochemical reaction is followed by surface isomerizations whose rate constants vary from 7 to 200 s−1 for the trans/cis and from 1 to 2000 s−1 for the cis/trans transformations.

Electrochemical synthesis of 2-arylimino-4,5-di(2-furyl)-1,3-dioxoles and (E)-1,2-di(2-furyl)vinylene bis(N-arylchloroformimidates). HF and B3LYP com…

2009

Abstract Cathodic reductions of 2,2′-furils in the presence of N-arylcarbonimidoyl dichlorides lead to 2-arylimino-4,5-di(2-furyl)-1,3-dioxoles in high yields, along with minor amounts of (E)-1,2-di(2-furyl)vinylene bis(N-arylchloroformimidates). HF and B3LYP density functional theory methods have been applied to the determination of molecular geometries and to study the topomerization mechanism of aryliminodioxoles. The molecular structure of (E)-1,2-di(2-furyl)vinylene bis[N-(2-chloro-4-methylphenyl)chloroformimidate] has been determined by X-ray crystallography and compared with the calculated structure.

The heterodinuclear iron(III) and copper(II) molecule Cu(salen)Fe(acac)2NO3 and its iron precursor Fe(acac)2NO3. Synthesis, magnetic susceptibility, …

1992

Abstract The synthesis, EPR, magnetic and Mossbauer properties of two iron(III) complexes are reported. The heterodinuclear iron(III)-copper(II) complex Cu(salen)Fe(acac)2NO3 is obtained as an adduct from the reaction of the two mononuclear moieties, the Cu(salen) molecule and the mononuclear iron(III) molecule Fe(acac)2NO3 acting as a precursor of the dinuclear unit. The latter molecule itself has been prepared by ligand substitution from the tris-acetylacetonate Fe(acac)3. The dinuclear complex is characterized by comparing the properties of the mono- and the dinuclear complex. Fe(acac)2NO3 is identified from its typical IR spectrum with the main nitrate vibrations at 1380, 1250 and 1010 …