2387-23-7Relevant articles and documents
Highly efficient ionic liquid-mediated palladium complex catalyst system for the oxidative carbonylation of amines
Shi, Feng,Peng, Jiajian,Deng, Youquan
, p. 372 - 375 (2003)
A highly efficient catalyst system, palladium-ionic liquid, was developed for the carbonylation of amines to give carbamate or urea. The desired products could be precipitated by adding water into the resulting mixture and the catalyst system could be reused with slight loss of catalytic activity. BMImBF4 ionic liquid + Pd(phen)Cl2 was an effective catalytic system for the oxidative carbonylation of aniline to give corresponding carbamate and for the cyclohexyl amine to give urea. The diversity of the ionic liquids could form an optimal homogeneous catalyst system with a specific organometallic toward specific reactions. There existed strong interactions between the ionic liquid and the Pd complex, which might enhance and stabilize the Pd complex catalyst.
Synthesis, characterization and hirshfeld surface analysis of a 2-thiophene acetic acid derivative
Rani, N. Latha,Chakravarthy,Mohana,Lokanath,Sridhar
, p. 223 - 231 (2015)
N,N′-dicyclohexylcarbamoyl-2-(thiophen-2-yl)acetamide (C19H28N2 O2S), was prepared using 1,3-dicyclohexylurea. The compound has been characterized by IR, and single-crystal X-ray diffraction followed by a detailed Hirshfeld surface analysis. The compound crystallizes in the monoclinic space group P21/c, with cell parameters a = 9.0969(3) ?, b = 18.3067(5) ?, c = 11.6499(3) ?, β = 103.876(2)°, V = 1883.49(10) ?3, Z = 4. The crystal structure of the compound is stabilized by the intermolecular interactions of types N-H?O, C-H?O and intramolecular interactions of the type C-H?O.
Preparation of 5-diaminomethylenebarbiturates by barbituric acid addition to carbodiimides
Jursic, Branko S.,Douelle, Fred,Stevens, Edwin D.
, p. 3427 - 3432 (2003)
Through NMR spectroscopic monitoring of barbituric acid addition to carbodiimide, a general synthetic procedure for the preparation of 5-diaminomethylenebarbiturates (DABA) was developed. This procedure is very simple and applicable to the preparation of large quantities of DABA derivatives. Through an X-ray structural study of one of the DABA derivatives, it was established that these compounds have an ylide-type structure with strong charge separation within the molecule.
Cytotoxicity of doxorubicin conjugated with C60 fullerene. Structural and in vitro studies
Butowska, Kamila,Kozak, Witold,Zdrowowicz, Magdalena,Makurat, Samanta,Rych?owski, Micha?,Ha?, Aleksandra,Herman-Antosiewicz, Anna,Piosik, Jacek,Rak, Janusz
, p. 2327 - 2338 (2019)
Conjugating an anticancer drug of high biological efficacy but large cytotoxicity with a “transporting” molecule of low toxicity constitutes a valuable approach to design safe drug delivery system. In the present study, doxorubicin (DOX) a drug of large cardiotoxicity was chemically conjugated to a C60-fullerene. The synthesized molecule, a fullerene-doxorubicin conjugate (Ful-DOX), was characterized using the 1H NMR and MALDI TOF mass spectrometry. The absorption and fluorescence spectra and dynamic light scattering of the conjugate were recorded in an aqueous solution, while the impact on viability of several cancer cell lines of the free DOX and the conjugate was compared using the SRB and WST-1 assays. A low antiproliferative activity of the conjugate as compared to the free DOX is a consequence of the presence of fullerene moiety in the former, which is also responsible for the conjugate aggregation in an aqueous solution. Unlike free DOX, these aggregates cannot pass through the nuclear membrane (as demonstrated by the confocal microscopy measurements), which makes them marginally cytotoxic.
Molecular interactions of β-cyclodextrins with monolayers containing adamantane and anthraquinone guest groups
Swiech, Olga,Chmurski, Kazimierz,Bilewicz, Renata
, p. 461 - 466 (2010)
Complexing abilities of β-cyclodextrin (β-CD) towards anthraquinone derivatives in solution and immobilised on gold surfaces were studied by voltammetry. The association constant of β-CD with 1-aminoanthraquinone in solution was found to be 1.03±0.05×103 M-1 hence, smaller than that with anthraquinone. Capping the surface-immobilised N-(1-anthraquinone) lipoamide with β-CD led to decrease in the heterogeneous electron transfer rate constant due to the change in the immediate environment around the electroactive group. To detect the interactions of β-CD with a non-electroactive guest, N-(1-adamantane) lipoamide (AD-Lip), the CD was modified by the attachment of an anthraquinone group as the electroactive marker. The appearance of the voltammetric peak corresponding to the reduction of the anthraquinone side-group indicated the binding of β-CD to the AD-Lip self-assembled in a monolayer on the gold electrode.
N-(3-Triethoxysilylpropyl)-4-(isothiocyanatomethyl)-cyclohexane-1-carboxamide (TPICC): A heterobifunctional reagent for immobilization of biomolecules on glass surface
Misra, Arvind,Shahid, Mohammad,Dwivedi, Pratibha
, p. 5217 - 5221 (2008)
An efficient heterobifunctional reagent, N-(3-triethoxysilylpropyl)-4-(isothiocyanatomethyl)cyclohexane-1-carboxamide (TPICC) has been developed by a simple 'two step reaction' for the preparation of bioconjugates and immobilization of biomolecules such as oligonucleotides, peptides and proteins on the glass surface. The isothiocyanate functionality at one end of the reagent, TPICC was found specific for the ligands having either aminoalkyl (RNH2) or mercaptoalkyl (R-SH) functionality. The synthesis of bioconjugates with the reagent was achieved through its isothiocyanate functionality at one end via the formation of stable thiourea linkage with aminoalkyl and dithiocarbamate linkage with mercaptoalkyl derivatives. The triethoxysilyl functionality of the reagent has been utilized for specific coupling with the virgin glass surface by a very simple methodology.
Total Synthesis of (+)-3-Demethoxyerythratidinone and (+)-Erysotramidine via the Oxidative Amidation of a Phenol
Paladino, Marco,Zaifman, Joshua,Ciufolini, Marco A.
, p. 3422 - 3425 (2015)
Oxidative amidation chemistry provides a unified route to aromatic Erythrina alkaloids through a sequence that illustrates new principles and improved conditions to effect a crucial eliminative Curtius-Schmidt rearrangement.
A chirally stable, atropoisomeric, Cα-tetrasubstituted α-amino acid: Incorporation into model peptides and conformational preference
Formaggio, Fernando,Peggion, Cristina,Crisma, Marco,Toniolo, Claudio,Tchertanov, Luba,Guilhem, Jean,Mazaleyrat, Jean-Paul,Goubard, Yolaine,Gaucher, Anne,Wakselman, Michel
, p. 481 - 501 (2001)
A variety of model peptides, including four complete humologous series, to the pentamer level, characterized by the recently proposed binaphthyl-based, axially chiral. Cα-tetrasubstituted, cyclic α-amino acid Bin, in combination with Ala. Gly, or Aib residues, was synthesized by solution methods and fully characterized. The solution conformational propensity of these peptides was determined by FT-IR absorption and 1H-NMR techniques. Moreover, the molecular structures of the free amino acid (S)-enantiomer and an Nα-acylated dipeptide alkylamide with the heterochiral sequence -(R)-Bin-Phe- were assessed in the crystal state by X-ray diffraction. Taken together, the results point to the conclusion that β-bends and 310 helices are preferentially adopted by Bin-containing peprides, although the tully extended conformation would also be adopted in solution by the short oligomers to some extent. We also confirmed the tendency of (R)-Bin to fold a peptide chain into right-handed bend and helical structures. The absolute configuration of the Bin residue(s) was correlated with the typically intense exciton-split Cotton effect of the 1Bb binaphthyl transition near 225 nm.
Biodegradable thermo-sensitive nanoparticles from poly(L-lactic acid)/poly(ethylene glycol) alternating multi-block copolymer for potential anti-cancer drug carrier
Na, Kun,Lee, Kwang Hee,Lee, Don Haeng,Bae, You Han
, p. 115 - 122 (2006)
In order to produce biodegradable thermo-sensitive nanoparticles, alternating multi-block copolymers (MBC) were synthesized by coupling dicarboxylated poly(ethylene glycol) (PEG; Mw 2000) with poly(l-lactic acid) (PLLA)/PEG/PLLA triblock copolymers. Three different multi-block copolymers were synthesized by varying PLLA molecular weight (800 (MBC1), 1600 (MBC2), and 2800 (MBC3)). The MBC formed self-assembled nanoparticles with a unimodal size distribution during a dialysis process. The nanoparticles (NP) had a spherical shape with a size range of 90-330 nm in diameter and critical aggregation concentrations in a range of 5.6-12.6 μg/mL, depending on PLLA length in MBC. The thermo-sensitivity of MBC NP was monitored by the changes in particle size and interior structure as a function of temperature. The particle size slightly decreased as increasing temperature from 37 to 42°C. The interior structure of the NP responded to temperature by altering microviscosity. The microviscosity, measured by the anisotropy (r value) of a fluorescence probe, of MBC1 NP significantly changed with increasing temperature (r = 0.187 at 25°C and 0.216 at 42°C), while MBC2 and MBC3 showed negligible changes in the microviscosity. This indicates that the temperature-dependent interior structure of the NP relied on the portion of PLLA in MBC. The thermo-sensitivity affected to the drug release behavior and cell cytotoxicity. At 42°C, doxorubicin (DOX) loaded MBC1 NP showed enhanced cytotoxicity (～20 times) against Lewis Lung Carcinoma (LLC) cells when compared to that at 37°C.
One-pot synthesis of 4-arylidene imidazolin-5-ones by reaction of amino acid esters with isocyanates and α-bromoketones
Haung, Jia-Yun,Barve, Indrajeet J.,Sun, Chung-Ming
, p. 3040 - 3047 (2019)
A simple and new multicomponent reaction for the one-pot synthesis of substituted 4-arylidene imidazolin-5-ones from l-amino acid methyl esters, iso-, isothio- or isoselenocyanates, and α-bromoketones is demonstrated. Isolation of thiohydantoin and 5-benzylidene 2-thioxoimidazolidin-4-one intermediates revealed a possible reaction mechanism. The strategy was further extended to the synthesis of 2-iminothiazolines and 2-thioxoimidazolin-4-ones.
