17356-08-0Relevant articles and documents
Oxyhalogen-sulfur chemistry: Oxidation of a thiourea dimer, formamidine disulfide, by chlorine dioxide
Martincigh, Bice S.,Mhike, Morgen,Morakinyo, Kayode,Adigun, Risikat Ajibola,Simoyi, Reuben H.
, p. 362 - 369 (2013)
The oxidation of formamidine disulfide, FDS, the dimer of thiourea, by aqueous chlorine dioxide has been studied in highly acidic and mildly acidic media. FDS is one of the possible oxidation intermediates formed in the oxidation of thiourea by oxyhalogens to urea and sulfate. The reaction is exceedingly slow, giving urea and sulfate with a stoichiometric ratio of 5:14 FDS to chlorine dioxide after an incubation period of up to 72h and only in highly acidic media which discourages the disproportionation of chlorine dioxide to the oxidatively inert chlorate. Mass spectrometric data suggest that the oxidative pathway proceeds predominantly through the sulfinic acid, proceeding next to the products sulfate and urea, while by-passing the sulfonic acid. Transient formation of the unstable sulfenic acid was also not observed.
Solvent-free ring cleavage hydrazinolysis of certain biginelli pyrimidines
Said, Mohamed A.,Eldehna, Wagdy M.,Ghabbour, Hazem A.,Kabil, Maha M.,Al-shakliah, Nasser S,Abdel-Aziz, Hatem A
, (2018)
Certain Biginelli pyrimidines with ester substitution in C5 were subjected to unexpected ring opening upon solvent-free reaction with hydrazine hydrate to give three products: pyrazole, arylidenehydrazines, and urea/thiourea, respectively. The nonisolable carbohydrazide intermediates are formed firstly followed by the intermolecular nucleophilic attack of terminal amino group of hydrazide function on sp2 C6 rather than the sp3 C4 to give the ring adduct which was produced as a final product.
Electrooxidation of Formamidine Disulfide Simultaneously Investigated by On-Line High Performance Liquid Chromatography and Cyclic Voltammetry
Feng, Na,Li, Fengli,Liu, Yang,Luo, Hainan,Zhang, Baoying,Zhang, Wei,Zhao, Yuyan
, p. 1074 - 1080 (2021/11/03)
The electro-oxidation of formamidine disulfide, an important sulfur-containing compound, was simultaneously investigated with on-line high-performance liquid chromatography and cyclic voltammetry. Using a home-made microporous sampler located at the electrode interface, the solution on the electrode surface was in situ sampled and analyzed. The electrochemical scanning was synchronously performed, which allowed the electro-oxidation products to be detected at a given potential. The main products on the surface of platinum electrode were found to be thiourea, formamidine sulfinic acid, cyanamide, and elemental sulfur. Forced convection arising from the sampling played an important role in the electrochemical oxidation. The extraction of electrode surface solution promoted the renewal of reactant and its intermediates, which induced the change of cyclic voltammetry curve. The forced convection also contributed to the redox peak current of the species on the cyclic voltammetry curves through the change of concentration of reactant and its intermediates. This technique can help to explore the reaction mechanism of complex electrochemical reactions.
Photooxygenation of N-(2-thiazolyl)sulfanilamide, 2-(4-thiazolyl) benzimidazole, and thiacetazone
Jain, Shubha,Chourey, Meena,Jetti, Srinivasa Rao
, p. 155 - 157,3 (2020/09/09)
In the present work, photolysis of N-(2-thiozolyl)sulfanilamide, 2-(4-thiazolyl)benzimidazole and thiacetazone in presence of benzophenone as a sensitizer under 125 W UV Lamp has been reported. Structures of the products have been established by spectral and elemental analysis.
Kinetic study on hydrolysis and oxidation of formamidine disulfide in acidic solutions
Hu, Ying,Feng, Jiamin,Li, Yanwei,Sun, Yanyan,Xu, Li,Zhao, Yuemin,Gao, Qingyu
experimental part, p. 235 - 241 (2012/03/22)
Hydrolysis and oxidation of formamidine disulfide in acidic medium were investigated using high-performance liquid chromatography (HPLC) and mass spectrometry (MS) at 25 °C. By controlling the slow reaction rate and choosing appropriate mobile phase, HPLC provides the unique advantages over other methods (UV-Vis, chemical separation) in species tracking and kinetic study. In addition to thiourea and formamidine sulfinic acid, two unreported products were also detected in the hydrolysis reaction. Mass spectrometry measurement indicates these two products to be formamidine sulfenic acid and thiocyanogen with mass weights of 92.28 and 116.36, respectively. In the oxidation of formamidine disulfide by hydrogen peroxide, besides thiourea, formamidine sulfenic acid, formamidine sulfinic acid, thiocyanogen and urea, formamidine sulfonic acid and sulfate could be detected. The oxidation reaction was found to be first order in both formamidine disulfide and hydrogen peroxide. The rate constants of hydrolysis and oxidation reactions were determined in the pH range of 1.5-3.0. It was found both rate constants are increased with the increasing of pH. Experimental curves of different species can be effectively simulated via a mechanism scheme for formamidine disulfide oxidation, including hydrolysis equilibrium of formamidine disulfide and irreversible hydrolysis of formamidine sulfenic acid.
Hydrolysis of 2,4-dithiophenobarbital
Tarsa, Monika,Zuchowski, Grzegorz,Stasiewicz-Urban, Anna,Bojarski, Jacek
experimental part, p. 123 - 128 (2009/06/20)
Hydrolysis of 2,4-dithiophenobarbital in aqueous solutions of pH 2 - 12 was investigated at 40 and 60°C using UV spectrophotometry. The values of reaction order, rate constants, pKal and pKa2 and activation energy were determined. The preliminary estimation of degradation products was accomplished using thin layer chromatography. The major products were isolated by circular chromatography and identified by spectroscopic and classical methods.
Desulfurization and transformation of isothiocyanates to cyanamides by using sodium bis(trimethylsilyl)amide
Chen, Chun-Yen,Wong, Fung Fuh,Huang, Jiann-Jyh,Lin, Shao-Kai,Yeh, Mou-Yung
supporting information; scheme or table, p. 6505 - 6507 (2009/04/06)
Sodium bis(trimethylsilyl)amide was first used as the desulfurizing agent for the conversion of isothiocyanates to cyanamides in a 'one-flask' reaction. Crown Copyright
Stereocontrolled synthesis of functionalized cis-cyclopentapyrazolidines by 1,3-dipolar cycloaddition reactions of azomethine imines
Gergely, Joshua,Morgan, Jeremy B.,Overman, Larry E.
, p. 9144 - 9152 (2007/10/03)
(Chemical Equation Presented) The reaction of alkene-tethered α-ketocarboxylic acid derivatives with monosubstituted hydrazines allows highly substituted cis-cyclopentapyrazolidine ring systems 4 to be constructed rapidly. Successful cyclocondensations are realized under thermal reaction conditions; in some cases, protic or Lewis acids accelerate these reactions. α-Methoxy-α,β-unsaturated esters are suitable alkene components, as are alkenes having either electron-withdrawing or electron-donating substituents at the terminal alkene carbon. α-Ketoesters, α-ketoamides, and α-ketothioesters can be employed. Various hydrazines substituted with N-acyl, N-carboalkoxy, or N-carbamothioyl protecting groups are tolerated in these transformations. The rate of intramolecular cycloaddition is found to reflect not only the reactivity and equilibrium concentration of the azomethine imine intermediate, but, also in some cases, the rate at which hydrazone stereoisomers interconvert under the reaction conditions.
Substitute 1-(piperidin-4-yl)-3-(aryl)-isothioureas, their preparation and therapeutic use
-
, (2008/06/13)
The invention concerns compounds of formula (I) wherein: R1 and R2, identical or different, represent a saturated or unsaturated alkyl radical, branched or not and containing 1 to 7 carbon atoms; R3 to R8, identical or different, represent a hydrogen, an alkyl branched or not and containing 1 to 5 carbon atoms, an acyloxy, branched or not and containing 1 to 5 carbon atoms, a halogeno, nitro, hydroxy, acyl or alkoxy group containing 1 to 5 carbon atoms, a dialkylamino group containing 1 to 5 carbon atoms, a trifluoromethyl or trifluoro methoxyl group; Z represents an oxygen or sulphur atom or methylene; m represents an integer between 0 and 4 inclusively; n represents an integer between 2 and 7 inclusively; and their pure enantiomers and mixtures, the therapeutically acceptable mineral or organic salts of the compounds of formula (I) and their possible hydrates.
Compounds useful as reversible inhibitors of cysteine proteases
-
, (2008/06/13)
Disclosed are novel cathepsin S, K, F, L and B reversible inhibitory compounds of the formula (Ia) and (Ib) where R2, R3, R4, R5, R6, R7, R8, Het and X are defined herein. The compounds are useful for treating autoimmune and other diseases. Also disclosed are processes for making such novel compounds.
