98-10-2Relevant articles and documents
MECHANISTIC INVESTIGATIONS WITH POSITIVE HALOGENS: KINETICS OF OXIDATION OF THIOSEMICARBAZIDE BY CHLORAMINE-B, BROMAMINE-B AND DICHLORAMINE-B IN ACID MEDIUM
Gowda, B. Thimme,Bhat, J. Ishwara
, p. 2119 - 2128 (1987)
Kinetics of oxidation of thiosemicarbazide (TSC) by chloramine-B (CAB), and bromamine-B (BAB) in aqueous perchloric acid medium and by dichloramine-B (DCB) in 1:1 (v/v) water-methanol medium has been studied.The rate followed first order kinetics in and inverse fractional order in with all the oxidants.But it was fractional order in with CAB and independent of with BAB and DCB.Addition of benzenesulphonamide, the reduced product of the oxidants had no effect on the rate with CAB and BAB but it slightly increased the rate with DCB.Therate decreased with increase in ionis strength of the medium in all cases.Decrease of dielectric constant of the reaction medium by adding methanol had no effect on the rate with CAB and BAB but increased the rate with DCB.The mechanisms proposed and the derived rate laws are in conformity eith the observed results.The coefficients of the rate limiting steps have been calculated.Kinetics observed with HOCl and HOBr support the proposed mechanisms.
Synthesis and X-Ray Structure of Bistetraphenylphosphonium Tris(phenylsulphonylimino)sulphite
Roesky, Herbert W.,Schmieder, W.,Sheldrick, William S.
, p. 1013 - 1014 (1981)
An aza-analogue of sulphite, the structure of which was determined by X-ray diffraction, is prepared from sodium amide and a sulphur di-imide in liquid ammonia.
Chloraminometric and bromaminometric oxidation of sulfanilic acid in alkaline medium: A comparative kinetic and mechanistic study
Puttaswamy,Jagadeesh
, p. 48 - 56 (2006)
The kinetics of oxidation of sulfanilic acid (SAA) by chloramine-B (CAB) and bromamine-B (BAB) has been investigated in alkaline medium at 35 ± 0.1°C. The oxidation reaction follows identical kinetics in the case of both the oxidants with first-order dependence on each [oxidant]o and [SAA]o and an inverse first-order dependence on [OH-]. The variation of ionic strength, dielectric constant of the medium, addition of the reaction product (benzene-sulfonamide), and halide ions showed no significant influence on the reaction rate. Proton inventory studies made in H2O-D2O mixtures for CAB and BAB have been utilized to calculate the isotopic fractionation factor. The reaction has been studied at different temperatures, and activation parameters for the composite reaction have been computed from the Arrhenius plots. N-Hydroxylaminobenzene-4-sulfonic acid was identified as the oxidation product of SAA from IR and GC-MS analysis. A mechanism consistent with the kinetic results is proposed in which PhSO 2NHX (X = Cl or Br) interact with the substrate in the rate-limiting step. A suitable rate law is derived. The rate of oxidation of sulfanilic acid is about fourfold faster in BAB compared to CAB. The oxidation of SAA brought about by CAT and BAT was also investigated under identical experimental conditions, and the overall rate of oxidation of SAA increases in the order: BAB > BAT > CAB > CAT This may be attributed to the difference in electrophilicities of Cl+ and Br+ ions and also the van der Waal's radii of chlorine and bromine.
SELECTIVE NON-CYCLIC NUCLEOTIDE ACTIVATORS FOR THE CAMP SENSOR EPAC1
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Paragraph 00174-00176; 00198; 00277, (2021/09/26)
The invention relates generally to novel EPAC1 activators, such as Formula (I) and (II) and the preparation thereof as well as the use of EPAC1 activators disclosed herein as to selectively activate EPAC1 in cells.
Synthesis of magnetic chitosan supported metformin-Cu(II) complex as a recyclable catalyst for N-arylation of primary sulfonamides
Ahmadpoor, Fatemeh,Nasrollahzadeh, Mahmoud,Nezafat, Zahra,Pakzad, Khatereh
, (2021/06/25)
The application of chitosan, which has received much attention as a natural polymer and effective support, has many advantages such as biodegradability and biocompatibility. In this study, the immobilization of a copper complex on the magnetic chitosan bearing metformin ligand has been developed through immobilizing structurally defined metformin with long tail of (3-chloropropyl)trimethoxysilane (TMOS). The synthesized Fe3O4-chitosan@metformin-Cu(II) complex (Fe3O4-CS@Met-Cu(II)) was used as an effective, reusable and magnetic catalyst in the N-arylation of different derivatives of primary sulfonamides with arylboronic acids in ethanol. The primary sulfonamides were prepared from the reaction of sulfonyl chlorides with sodium cyanate in water under ultrasonic irradiation. Utilizing a wide variety of substrates in EtOH as a green solvent, high yields of the primary and secondary sulfonamides, easy work-up along with the excellent recovery and reusability of the catalyst, make this process a simple, economic and environmentally benign method. The synthesized Fe3O4-CS@Met-Cu(II) was characterized using various techniques such as XRD (X-ray diffraction), EDS (energy-dispersive X-ray spectroscopy), elemental mapping, TEM (transmission electron microscopy), FESEM (field emission scanning electron microscopy), VSM (vibrating sample magnetometer), ICP-MS (inductively coupled plasma mass spectroscopy), TGA (thermogravimetric analysis) and FT-IR (Fourier-transform infrared spectroscopy) analyses. The catalyst can be recycled and reused 5 times with no considerable loss of catalytic activity.