62821-88-9Relevant academic research and scientific papers
A pyrazolylamine-phosphonate monoester chelator for the fac-[M(CO) 3]+ core (M = Re, 99mTc): Synthesis, coordination properties and biological assessment
Palma, Elisa,Oliveira, Bruno L.,Figueira, Flavio,Correia, Joao D. G.,Raposinho, Paula D.,Santos, Isabel
, p. 1176 - 1184 (2007)
Aiming to develop new strategies for the labeling of hydroxyl-containing biomolecules with the organometallic core fac-[99mTc(CO) 3]+, we have prepared a new model bifunctional chelator, L4 (ethyl hydrogen (2-{[2-(3,5-dimethyl-1H-pyrazol-l-yl)ethyl]amino}ethyl) phosphonate), combining a pyrazolyl-amine chelating group and a monophosphonate ethyl ester function (-P(O)OHOEt). The phosphonate group allows metal stabilization, and, simultaneously, can be considered as a potential attachment site for a biomolecule. Reaction of L4 with the precursor [ 99mTc(H2O)3(CO)3]+ gave the model radiocomplex [99mTc(CO)3(k3-L4)] (6a). This radiocomplex was identified by comparing its chromatographic profile with that of the corresponding Re analog (6) under the same conditions, also prepared and fully characterized by the usual analytical techniques. Radiocomplex 6a is moderately lipophilic (log Po/w = 1.07), presenting high stability in vitro without any measurable decomposition or ligand exchange, even in the presence of strong competing chelators such as histidine and cysteine (37°C, 24h). Biodistribution studies of the complex in CD-1 mice indicated a rapid blood clearance, and a rapid clearance from main organs, occurring primarily through the hepatobiliary pathway. Complex 6a presents also a high robustness in vivo, demonstrated by its resistance to metabolic degradation in blood, and intact excretion into the urine, after RP-HPLC analysis of blood and urine samples. Copyright
Synthesis, characterization and metal-uptake behaviour of pyrazole ligands immobilized on silica
Verweij, P. D.,Haanepen, M. J.,Ridder, J. J. de,Driessen, W. L.,Reedijk, J.
, p. 371 - 378 (1992)
The novel didentate ligand 2-(3,5-dimethyl-1-pyrazolyl)ethylamine (Naed) and the tridentate ligand bis amine (ddaH) were immobilized onto silica by two different methods.The first method involves the coupling of the ligand to silica, previously modified with (3-glycidyloxypropyl)trimethoxysilane (GLYMO).The second method involves the coupling of the ligand to the oxirane ring of GLYMO in a homogeneous reaction, followed by grafting onto silica, yielding the highest ligand concentrations on the silica (about 0.3 mmol/g silica).With the first method, only part of the epoxy group reacts with the ligand.With Naed, tertiary amines are also formed through reaction of the primary amine group of the ligand with two epoxy groups. These new ion-exchange materials selectively adsorb Cu(2+) (maximum capacity 0.11-0.26 mmol Cu(2+) per gram of ion exchange) at pH > 2 from aqueous solutions containing a mixture of the bivalent metal ions, Cu(2+), Cd(2+), Zn(2+), Ni(2+) and Co(2+) .For products containing the didentate ligand Naed as the chelating group, the metal-ion capacity decreases rapidly with decreasing pH, while the Cu(2+)-uptake capacity for the product containing the tridentate ligand ddaH is comparatively high at low pH.
Copper (II) complexes with novel Schiff-based ligands: synthesis, crystal structure, thermal (TGA–DSC/FT-IR), spectroscopic (FT-IR, UV-Vis) and theoretical studies
Moreira, Jeniffer Meyer,Campos, Guilherme Fava,de Campos Pinto, Leandro Moreira,Martins, Gabriel Rodrigues,Tirloni, Bárbara,Schwalm, Cristiane Storck,de Carvalho, Cláudio Teodoro
, p. 4087 - 4098 (2021/05/10)
This study aimed to synthesize two novel Schiff-base ligands through the condensation between N-(2-aminoethyl)pyrazoles and 2-hydroxy-1-naphthaldehyde, which are: NaphPz ((E)-1-(((2-(1H-pyrazol-1-yl)ethyl)imino)methyl)naphthalen-2-ol)) and NaphDPz ((E)-1-(((2-(3,5-dimethyl-1H-pyrazol-1-yl)ethyl)imino)methyl)naphthalen-2-ol). These novel pyrazole-imines were synthesized, characterized and used as copper (II) ion complexing agents. Different synthetic routes have been adapted to obtain the [Cu(NaphPz)Cl], [Cu(NaphDPz)Cl] and [Cu(NaphPz)2] complexes in the solid state, the first two in the crystalline form and the latter as a powder. The minimum metal–ligand stoichiometry for the three complexes was defined by TGA–DSC thermoanalytical data and by single-crystal X-ray diffraction for the crystalline samples which belong to the P21/n space group. The products of the thermal decomposition of the material were also monitored by TGA–DSC/FT-IR in air and N2 atmospheres in order to suggest how thermal decomposition of the organic portion of the complex occurs. Density functional theory (DFT) and time-dependent density functional theory (TD-DFT) calculations compared to experimental results (UV-Vis and FT-IR) show a high degree of correlation. From HOMO/LUMO orbitals, the main major charge distributions, responsible for the absorption bands of the complexes, were determined.
New catalytic model systems of tyrosinase: Fine tuning of the reactivity with pyrazole-based N-donor ligands
Hamann, Jessica Nadine,Tuczek, Felix
supporting information, p. 2298 - 2300 (2014/03/21)
Two new Cu(I) complexes have been synthesized and investigated as model systems of the enzyme tyrosinase. The corresponding ligands are based on a combination of an imine function with two different pyrazole groups. The reactivity of the prepared systems with respect to the conversion of monophenols to the corresponding ortho-quinones is investigated. The resulting data are compared to results obtained for other catalytic model systems of tyrosinase. The Royal Society of Chemistry 2014.
Synthesis of 1-(2-aminoethyl)pyrazoles under phase-transfer catalysis
Attaryan,Baltayan,Sagatelyan,Takmazyan
, p. 136 - 138 (2008/09/18)
Alkylation of pyrazoles with 2-chloroethylamine was performed under conditions of phasetransfer catalysis. Depending on the substrate acidity, the electrophilic substitution process may be accompanied by dehydrochlorination of the alkylating agent, so that 6 equiv of 2-chloroethylamine should be used in the alkylation of 3,5-dimethylpyrazole.
Rhenium(v) oxocomplexes with novel pyrazolyl-based N4- and N3S-donor chelators
Moura, Carolina,Vitor, Rute F.,Maria, Leonor,Paulo, Antonio,Santos, Isabel,Santos, Isabel C.
, p. 5630 - 5640 (2008/02/12)
The novel pyrazolyl-based ligands 3,5-Me2pz(CH2) 2NH(CH2)2NH(CH2)2NH 2 (1) and pz*(CH2)2NH-Gly-CH 2STrit (pz* = pz (8), 3,5-Me2/
ALKYLATION OF AZOLES USING beta -FUNCTIONAL ALKYL HALIDES UNDER CONDITIONS OF PHASE TRANSFER CATALYSIS.
Asratyan,Attaryan,Pogosyan,Eliazyan,Darbinyan,Matsoyan
, p. 1202 - 1206 (2007/10/02)
The objective of this study was to develop a convenient synthetic method for direct N-alkylation of pyrazole (I), 3(5)-methylpyrazole (II), 3,5-dimethylpyrazole (III), 1,2,4-triazole (IV), and tetrazole (V) using beta -functional alkyl halides under conditions of two-phase catalysis and with high product yields. This investigation was stimulated by the fact that the desired reaction products are intermediates in the synthesis of an important class of compounds, vinylazole, as well as of various pharmaceutical agents. It is found that depending on the acidity of the azole, alkylation with dichloroethane can be accompanied by beta -elimination. The effect of solvent on the course of alkylation reactions using dichloroethane has also been studied, and revealed that the reactions occur via the intermediacy of ion pairs rather than free anions.
