59068-43-8Relevant academic research and scientific papers
N2O4 chemisorbed onto n-propylsilica kryptofix 21 and kriptofix 22 as two new functional polymers for the fast oxidation of urazoles and 1,4-dihydropyridines
Chehardoli, Gholamabbas,Zolfigol, Mohammad Ali,Ghaemi, Ezat,Madrakian, Elaheh,Niknam, Khodabakhsh,Mallakpour, Shadpour
experimental part, p. 596 - 599 (2012/09/07)
3-Chloropropylsilica was reacted with Kriptofix 21 or 22 in the presence of triethylamine to form N-propylsilica Kryptofix 21 and Kriptofix 22. Then N 2O4 was added to each of these polymers to chemisorb onto cavity of aza-crown ethers. These functionalized polymers were applied for the fast and simple oxidation of urazoles and 1,4-dihydropyridines, respectively.
Construction of polyheterocyclic benzopyran library with diverse core skeletons through diversity-oriented synthesis pathway: Part II
Zhu, Mingyan,Lim, Byung Joon,Koh, Minseob,Park, Seung Bum
experimental part, p. 124 - 134 (2012/04/10)
As a continuation of our previous report (J. Comb. Chem.2010, 12, 548-558), we accomplished the diversity-oriented synthesis of polyheterocyclic small-molecule library with privileged benzopyran substructure. To ensure the synthetic efficiency, we utilized the solid-phase parallel platform and the fluorous-tag-based solution-phase parallel platform to construct a 284-member polyheterocyclic library with six distinct core skeletons with an average purity of 87% on a scale of 5-10 mg. This library was designed to maximize the skeletal diversity with discrete core skeletons in three-dimensional space and the combinatorial diversity with four different benzopyranyl starting materials and various building blocks. Together with our reported benzopyranyl library, we completed the construction of polyheterocyclic benzopyran library with 11 unique scaffolds and their molecular diversity was visualized in chemical space using principle component analysis (PCA).
Oxidative ring cleavage of 4-(4-R-phenyl)-1,2,4-triazolidine-3,5-diones: Electrochemical behavior and kinetic study
Varmaghani,Nematollahi,Mallakpour
scheme or table, p. F174-F180 (2012/07/28)
Cyclic voltammetry results as a diagnostic technique for electrochemical oxidation of 4-(4-R-phenyl)-1,2,4-triazolidine-3,5-diones (1-5) are reported and discussed. The results indicate that the electrochemically generated 4-(4-R-phenyl)-4H-1,2,4-triazole-3,5-diones (1ox-5ox) are unstable and participate in oxidative ring cleavage. In this study, the effect of different parameters such as pH, 4-phenylurazole concentration, solvent, temperature, substitute effect and time window of chosen electrochemical method have been studied. Also, the transfer coefficient, α, exchange current density, J0, the formal potential, E0′ and diffusion coefficient, D, of 4-phenylurazole (1) have been calculated. In addition, the observed homogeneous rate constants of oxidative ring cleavage of 4-phenylurazole derivatives were estimated by comparing the experimental cyclic voltammetric responses with digital simulated results.
Oxidation of urazoles to their corresponding triazolinediones using benzyltriphenylphosphonium nitrate
Samimi, Heshmat Allah,Parvanak, Kaveh
experimental part, p. 272 - 274 (2011/10/07)
Benzyltriphenylphosphonium nitrate in the presence of AlCl3 oxidised 1,2,4-triazolidine-3,5-diones to the corresponding 4-substituted-1,2,4- triazole-3,5-diones.
Catalytic and efficient oxidation of urazole derivatives to their corresponding triazolinediones using ammonium nitrate and metal hydrogen sulfate as catalyst
Ghorbani-Choghamarani, Arash,Zeinivand, Javad,Mallakpour, Shadpour
experimental part, p. 1189 - 1192 (2010/11/19)
Catalytic oxidation of a variety of urazoles to the triazolinediones via combination of NH4NO3 in the presence of a catalytic amount of aluminium hydrogen sulfate has been developed at room temperature in dichloromethane.
Metal-Free oxidation of urazole and 1,4-dihydropyridine derivatives under mild and heterogeneous conditions by nitro urea, derived from urea nitrate, and silica sulfuric acid
Ghorbani-Choghamarani, Arash,Zolfigol, Mohammad A.,Hajjami, Maryam,Rastgoo, Shahrbanoo,Mallakpour, Shadpour
scheme or table, p. 249 - 254 (2011/07/30)
Mild combination of nitro urea, derived from urea nitrate, and silica sulfuric acid (SiO2OSO3H) might act as an efficient oxidizing media, which could be able to oxidize different types of heterocyclic compounds including urazoles and 1,4-dihydropyridines. The process presented here is operationally simple, environmentally benign, and reactions have been mildly carried out in dichloromethane at room temperature.
Synthesis and anti-leishmanial activity of heterocyclic betulin derivatives
Alakurtti, Sami,Heiska, Tuomo,Kiriazis, Alexandros,Sacerdoti-Sierra, Nina,Jaffe, Charles L.,Yli-Kauhaluoma, Jari
experimental part, p. 1573 - 1582 (2010/05/02)
Betulin, a naturally occurring abundant triterpene is converted in four steps to 3,28-di-O-acetyllupa-12,18-diene. When various 4-substituted urazoles were oxidized to the corresponding urazines with iodobenzene diacetate in the presence of 3,28-di-O-acetyllupa-12,18-diene, new heterocyclic betulin derivatives were produced. These betulin derivatives were examined in a microplate assay at 50 μM for their ability to inhibit the growth of Leishmania donovani axenic amastigotes, a species that causes the fatal visceral leishmaniasis. GI50 (concentration for 50% growth inhibition) values of the most effective compounds were determined and their cytotoxicity on the human macrophage cell line THP-1 evaluated. The anti-leishmanial activity on L. donovani amastigotes growing in macrophages was also examined. The heterocycloadduct between 3,28-di-O-acetyllupa-12,18-diene and 4-methylurazine was the most effective derivative with an GI50 = 8.9 μM against L. donovani amastigotes.
Supported nitric acid on silica gel and polyvinyl pyrrolidone (PVP) as an efficient oxidizing agent for the oxidation of urazoles and bis-urazoles
Ghorbani-Choghamarani, Arash,Chenani, Zahra,Mallakpour, Shadpour
experimental part, p. 4264 - 4270 (2010/01/09)
A method for the oxidation of a good range of urazoles and bis-urazoles to the corresponding triazolinediones by supported nitric acid on silica gel (SiO2-HNO3) and/or polyvinyl pyrrolidone (PVP-HNO3) is described. Reactions have been carried out heterogeneously at room temperature in dichloromethane with good to excellent yields.
