- Method for preparing chlorinated-3-substituted-2,5-diphenyl tetrazole under catalysis of copper Lewis acid surfactant
-
The invention belongs to the technical field of organic synthesis and specifically relates to a method for preparing chlorinated-3-substituted-2,5-diphenyl tetrazole under the catalysis of a copper Lewis acid surfactant. The method comprises the following steps: 1) reacting benzaldehyde, phenylhydrazine, arylamine and sodium nitrite in solvent water by taking a copper Lewis acid surfactant Cu(OSO2CnH2n+1)2 as a catalyst to obtain 3-aryl-2,5-diphenylformazan; and 2) cyclizing and chlorinating 3-aryl-2,5-diphenylformazan in a mixed solvent of dichloromethane and water under the condition of a solid chlorination reagent N-chlorosuccinimide to obtain chlorinated-3-substituted-2,5-diphenyl tetrazole. By using the method, three-step conversion is completed according to a ''one-pot method'' continuous strategy, not only is an intermediate separation step omitted, but also the purification step is simple as well as convenient and easy to operate.
- -
-
Paragraph 0057; 0058; 0059; 0064; 0065
(2018/09/12)
-
- Oxidation of 3-(3-or 4-pyridyl)-1,5-diphenylformazans in tetrazolium trichlorometallates: Structural and electrochemical investigation
-
On interacting pyridine-containing formazans with cobalt(II) and copper(II) chlorides the richlorometallates of the corresponding cations are isolated, the structures of which were established by X-ray structural analysis. Using data of cyclic voltamperometry a scheme is proposed for the oxidation-reduction process of converting formazans into tetrazolium cations.
- Frolova,Vatsadze,Stash,Rakhimov,Zyk
-
p. 1444 - 1456
(2008/09/21)
-
- Imidazole compounds
-
A novel class of imidazo heterocyclic compounds, pharmaceutical compositions comprising them and use thereof in the treatment and/or prevention of diseases and disorders related to the histamine H3 receptor. More particularly, the compounds are useful for the treatment and/or prevention of diseases and disorders in which an interaction with the histamine H3 receptor is beneficial.
- -
-
-
- Imidazo heterocyclic compounds
-
A novel class of imidazo heterocyclic compounds, pharmaceutical compositions comprising them and use thereof in the treatment and/or prevention of diseases and disorders related to the histamine H3 receptor. More particularly, the compounds are useful for the treatment and/or prevention of diseases and disorders in which an interaction with the histamine H3 receptor is beneficial.
- -
-
-
- 1-Chlorobenzotriazole-Mediated Ring Closure of 1,3,5-Triarylformazans: Improved Syntheses of 2,3,5-Triaryl-2H-tetrazolium Salts
-
Oxidative ring closure of mono- and bis-triarylformazans mediated by easily available 1-chlorobenzotriazole leads to the corresponding 2,3,5-triaryl-2H-tetrazolium chlorides in yields of 70-97percent.
- Katritzky, Alan R.,Belyakov, Sergey A.,Lam, Jamshed N.,Durst, H. Dupont,Karpenko, Dmitrii V.
-
-
- TETRAZOLES. 20. TETRAZOLIUM SALTS IN INTERPHASE CATALYSIS
-
Oxidation of substituted triarylformazanes by potassium permanganate in a two-phase organic solvent-water system in the presence of catalytic amounts of tetrabutylammonium bromide gives the corresponding tetrazolium salts, which are interphase transfer catalysts in oxidation, alkylation, and esterification.From distribution coefficient data it is concluded that 2,3,5-triphenyltetrazolium chloride has less catalytic activity than 2,5-diphenyl-3-(m-nitrophenyl)tetrazolium bromide.
- Osipova, T. F.,Koldobskii, G. I.,Ostrovskii, V. A.,Myznikov, Yu. E.
-
p. 700 - 703
(2007/10/02)
-
- Reaction between Tl(III)Acetate and 1,3,5-Triarylformazan - A Linear Free Energy Correlation of Oxidative Cyclisation
-
Tl(III) acetate oxidations of 1,3,5-triarylformazans have been studied in 90percent HOAc-10percent H2O (v/v).The oxidative cyclisation exhibits total second order kinetics.For 1 mol of Tl(III)acetate, 1 mol of formazan is consumed, yielding 95percent of tetrazolium salt.The reaction mixture does not initiate acrylonitrile polymerisation.The rate of oxidation is susceptible to polar influence of substituents in the phenyl rings of formazan.From the Hammett correlation (?o, ?p+, ?m), the reaction constants evaluated are -0.81, -0.75 and -0.80 respectively and the negative ρ-values are indicative of an electron deficient transition state.The high negative entropies of activation reveal that the transition state is more ordered, probably cyclic.The thermodynamic parameters have been subjected to Exner treatment and the plot of log kT2 versus log kT1 (T1 2) is linear, yielding the slope (=0.89) of less than unity and the isokinetic temperature calculated therefrom comes out to be 728 K, showing that the detailed structure-activity correlation is probably valid.From the influence of dielectric constant of the medium, it has been concluded that the reactants are dipolar in nature.
- Balakrishnan, R.,Srinivasan, Vangular S.
-
p. 771 - 775
(2007/10/02)
-
- Kinetics and Mechanism of Oxidative Cyclization of Formazans to Tetrazolium Salts by Thallium(III) Acetate
-
The kinetics of thallium(III) acetate oxidation of 1,3,5-triarylformazans have been investigated in acetic acid-water mixture.The reaction, which leads to tetrazolium salt as the product, follows the rate-law .The effect of substituent in the aldehyde (3-phenyl), the phenylhydrazine (l-phenyl) and the aryldiazonium (5-phenyl) moieties on the reaction rate has been studied and the corresponding Hammett rhos are -0.78, -0.85 and -0.8 respectively.A mechanism for the oxidative cyclization is proposed involving the formation of a N-thallated complex between the formazan and T1 (III) acetate which decomposes in a slow step accompanied by a ring closure between N-1 and N-5.
- Balakrishnan, R.,Srinivasan, V. S.,Venkatasubramanian, N.
-
p. 404 - 406
(2007/10/02)
-
