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• 52039-90-4 4-(3,4-dichlorophenyl)urazole 

Relevant academic research and scientific papers

Silica sulfuric acid/NaNO2 as a novel heterogeneous system for the oxidation of urazoles under mild conditions

Neat chlorosulfonic acid reacted with silica gel to give silica sulfuric acid (I) in which sulfuric acid functions immobilized on the surface of silica gel via covalent bonding. Urazoles and bis-urazoles can be readily converted to their corresponding triazolinediones with a combination of silica sulfuric acid (I), wet SiO2 and sodium nitrite in dichloromethane at room temperature.

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

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.

Oxidative ring cleavage of 4-(4-R-phenyl)-1,2,4-triazolidine-3,5-diones: Electrochemical behavior and kinetic study

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.

Catalytic and efficient oxidation of urazole derivatives to their corresponding triazolinediones using ammonium nitrate and metal hydrogen sulfate as catalyst

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

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.

Supported nitric acid on silica gel and polyvinyl pyrrolidone (PVP) as an efficient oxidizing agent for the oxidation of urazoles and bis-urazoles

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.

Catalytic oxidation of urazoles and bis-urazoles to their corresponding triazolinediones using aluminium nitrate and a catalytic amount of silica sulfuric acid

A simple and efficient catalytic oxidation of urazoles and a bis-urazole to the corresponding triazolinediones by treatment with Al(NO3) 3.9H2O in the presence of a catalytic amount of silica sulfuric acid is described. A good range of urazole derivatives was selectively oxidized in CH2Cl2 at room temperature in good to excellent yields.

Iodogen: A novel reagent for the oxidation of urazoles under heterogeneous conditions

Iodogen is employed as an efficient oxidizing agent for the conversion of urazoles and bis-urazoles into the corresponding 1,2,4-triazoles in good to excellent yields under mild heterogeneous conditions at room temperature. Georg Thieme Verlag Stuttgart.

N-bromo reagent mediated oxidation of urazoles to their corresponding triazolinediones under mild and heterogeneous conditions

Various N-bromo reagents [HMTAB, DABCO-bromine, DPTBE, and TBCA] were used as effective oxidizing agents for the oxidation of urazoles and bisurazoles to their corresponding triazolinediones under mild and heterogeneous conditions at room temperature with good to excellent yields. Also the oxidation of some new 4-phenylurazole derivatives with these reagents is discussed.

PEG-N2O4 system as an efficient reagent both for the rapid oxidation of urazoles and 1,4-dihydropyridines under nonaqueous conditions

N2O4 was easily impregnated on polyethyleneglycol to give a stable reagent. Polyethyleneglycol-N2O4 (PEG-N 2O4) system was used as an effective oxidizing agent for the oxidation of urazoles and bis-urazoles to their corresponding triazolinediones and also for the aromatization of 1,4-dihydropyridines into the corresponding pyridine derivatives under mild conditions at room temperature with good to excellent yields.