103-84-4Relevant articles and documents
Optimizing Water Exchange Rates and Rotational Mobility for High-Relaxivity of a Novel Gd-DO3A Derivative Complex Conjugated to Inulin as Macromolecular Contrast Agents for MRI
Granato, Luigi,Vander Elst, Luce,Henoumont, Celine,Muller, Robert N.,Laurent, Sophie
, (2018)
Thanks to the understanding of the relationships between the residence lifetime τM of the coordinated water molecules to macrocyclic Gd-complexes and the rotational mobility τR of these structures, and according to the theory for paramagnetic relaxation, it is now possible to design macromolecular contrast agents with enhanced relaxivities by optimizing these two parameters through ligand structural modification. We succeeded in accelerating the water exchange rate by inducing steric compression around the water binding site, and by removing the amide function from the DOTA-AA ligand [1,4,7,10-tetraazacyclododecane-1,4,7,10-tetraacetic acid mono(p-aminoanilide)] (L) previously designed. This new ligand 10[2(1-oxo-1-p-propylthioureidophenylpropyl]-1,4,7,10-tetraazacyclodecane-1,4,7-tetraacetic acid (L1) was then covalently conjugated to API [O-(aminopropyl)inulin] to get the complex API-(GdL1)x with intent to slow down the rotational correlation time (τR) of the macromolecular complex. The evaluation of the longitudinal relaxivity at different magnetic fields and the study of the 17O-NMR at variable temperature of the low-molecular-weight compound (GdL1) showed a slight decrease of the τM value (τM310 =?331?ns vs. τM310 =?450?ns for the GdL complex). Consequently to the increase of the size of the API-(GdL1)x complex, the rotational correlation time becomes about 360 times longer compared to the monomeric GdL1 complex (τR?=?33,700?ps), which results in an enhanced proton relaxivity.
Transition metal-free intermolecular a-C-H amination of ethers at room temperature
Buslov, Ivan,Hu, Xile
, p. 3325 - 3330 (2014)
We describe a new method for the intermolecular amination of the α-C-H bonds of ethers. A hypervalent iodine reagent was used as oxidant to enable the amination of cyclic and acyclic alkyl ethers with a wide range of amides, imides, and amines. The amination occurred at room temperature and without a transition metal catalyst. The method could be used to synthesize the anti-cancer prodrug Tegafur and its analogues.
Synthesis of 2-(N-cyclicamino)quinoline combined with methyl (E)-3-(2/3/4-aminophenyl)acrylates as potential antiparasitic agents
Bokosi, Fostino R. B.,Beteck, Richard M.,Laming, Dustin,Hoppe, Heinrich C.,Tshiwawa, Tendamudzimu,Khanye, Setshaba D.
, (2021)
A rationally designed series of 2-(N-cyclicamino)quinolines coupled with methyl (E)-3-(2/3/4-aminophenyl)acrylates was synthesized and subjected to in vitro screening bioassays for potential antiplasmodial and antitrypanosomal activities against a chloroquine-sensitive (3D7) strain of Plasmodium falciparum and nagana Trypanosoma brucei brucei 427, respectively. Substituent effects on activity were evaluated; meta-acrylate 24 and the ortho-acrylate 29 exhibited the highest antiplasmodial (IC50 = 1.4 μM) and antitrypanosomal (IC50 = 10.4 μM) activities, respectively. The activity against HeLa cells showed that the synthesized analogs are not cytotoxic at the maximum tested concentration. The ADME (absorption, distribution, metabolism, and excretion) drug-like properties of the synthesized compounds were predicted through the SwissADME software.
Synthesis of multilayer polymer-immobilised nanosilver for catalytic study in condensation reaction of aniline and acetylacetone
Basu, Jayanta Kumar,Maji, Nitai Chandra,Sengupta, Sonali,Supriya
, (2020)
Abstract: Silver nanoparticles were synthesized in green route with non-hazardous polyvinyl alcohol and polyvinylpyrrolidone as stabilizing as well as reducing agents and water as green solvent. This silver nanoparticle-embedded polymer composite film, Ag/PVA–PVP was characterized by UV–Vis spectroscopy, SEM and TEM. The catalytic activity of this film was evaluated in reduction of p-nitrophenol, acylation of aniline and synthesis of a β-enaminone, 4-phenylamino-pent-3-en-one with appreciably good results. β-enaminone synthesis reaction was chosen to study the effects of kinetic parameters such as reactant quantity, catalyst loading, solvents and temperatures. In a typical reaction, 89% conversion was achieved. A probable chemical reaction mechanism is suggested. Kinetic model fitting for the synthesis of β-enaminone reaction was done for the first time here. Heterogeneous kinetic model following Eley-Rideal pathway showed an excellent data fitting for the reaction. The rate law parameters were estimated. Graphic abstract: Scheme. Synthesis and catalytic application of multilayer polymer-immobilised nanosilver in condensation reaction of aniline and acetylacetone.[Figure not available: see fulltext.].
Impregnated copper on Fe3O4: an efficient magnetically separable nanocatalyst for rapid and selective acylation of amines
Shokri, Zahra,Zeynizadeh, Behzad
, p. 2467 - 2474 (2017)
The present paper describes the synthesis of N-arylacetamides through acetylation of arylamines with Ac2O in the presence of magnetically recyclable Fe3O4/Cu NPs. All reactions were carried out efficiently in H2O within 2–10?min to give the products in 89–95% yields. Selective acetylation of amines versus alcohols was carried out successfully with this acetylating system. In addition, acetylation of amines and phenols was taken place with the same reactivity. Reusability of the nanocatalyst was examined 5 times without significant loss of its catalytic activity.
METHYLKETENE, A MINOR BUT HIGHLY REACTIVE BYPRODUCT IN THE PYROLYSIS GAS OF ACETONE
Tschamber, Theophile,Streith, Jacques
, p. 4503 - 4506 (1980)
Methylketene was identified during the pyrolysis of acetone, and proved to be much more reactive than ketene: METHYL-β-LACTAMS were the dominant cycloaddition products when imines are reacted with the pyrolysis gas of acetone at ROOM TEMPERATURE.
A binuclear Mn(ii) complex as an efficient catalyst for transamidation of carboxamides with amines
Singh, Divya Pratap,Allam, Bharat Kumar,Singh, Krishna Nand,Singh, Vinod Prasad
, p. 1155 - 1158 (2014)
A binuclear Mn(ii) complex has been synthesized and characterized by different structural methods. The complex contains two unique oxo-bridged metal centres and has been explored as an excellent catalyst for transamidation of carboxamides with amines under solvent-free conditions.
An alternative and facile purification procedure of amidation and esterification reactions using a medium fluorous Mukaiyama reagent
Matsugi, Masato,Suganuma, Misaki,Yoshida, Shoko,Hasebe, Shohei,Kunda, Yoko,Hagihara, Kotaro,Oka, Sayaka
, p. 6573 - 6574 (2008)
A convenient methodology for the separation of a fluorous by-product using fluorous chemistry is described. A Mukaiyama coupling reagent bearing a medium fluorous tag, between 40% and 60% fluorine by weight, can be effectively separated from non-fluorous components by increasing the water content of the crude reaction mixture and subsequent filtration. Additional fluorous solid phase extraction is not necessary.
Harnessing the pyrroloquinoxaline scaffold for FAAH and MAGL interaction: Definition of the structural determinants for enzyme inhibition
Brindisi, Margherita,Brogi, Simone,Maramai, Samuele,Grillo, Alessandro,Borrelli, Giuseppe,Butini, Stefania,Novellino, Ettore,Allarà, Marco,Ligresti, Alessia,Campiani, Giuseppe,Di Marzo, Vincenzo,Gemma, Sandra
, p. 64651 - 64664 (2016)
This paper describes the development of piperazine and 4-aminopiperidine carboxamides/carbamates supported on a pharmacogenic pyrroloquinoxaline scaffold as inhibitors of the endocannabinoid catabolizing enzymes fatty acid amide hydrolase (FAAH) and monoacylglycerol lipase (MAGL). Structure-activity relationships and molecular modelling studies allowed the definition of the structural requirements for dual FAAH/MAGL inhibition and led to the identification of a small set of derivatives (compounds 5e, i, k, m) displaying a balanced inhibitory profile against both enzymes, with compound 5m being the frontrunner of the subset. Favorable calculated physico-chemical properties suggest further investigation for specific analogues.
Preparation, characterization and application of RHA/TiO2 nanocomposites in the acetylation of alcohols, phenols and amines
Seddighi, Mohadeseh,Shirini, Farhad,Goli-Jolodar, Omid
, p. 1003 - 1010 (2016)
In this work, anatase-phase nano-titania was prepared by embedding in rice husk ash, and identified using a variety of techniques. The obtained nanocomposite (RHA/TiO2) was used as a green and inexpensive catalyst for the promotion of the acetylation of alcohols, phenols and amines with Ac2O at room temperature under solvent free conditions. The procedure gave the products in excellent yields during all reaction times. Also this catalyst can be reused for several times without loss of its catalytic activity.
