65-85-0Relevant articles and documents
Redox Cascades and Making of a C-C Bond: 1,2-Benzodiazinyl Radicals and a Copper Complex of a Benzodiazine
Mondal, Sandip,Bera, Sachinath,Ghosh, Prasanta
, (2019)
Two 1,2-benzodiazinyl radicals, cinnolinyl radicals by name, were successfully isolated by cascade routes using 1,4-naphthoquinone as a precursor. Reaction of 1,4-naphthoquinone with hydrazine hydrate promotes a (5e + 5H+) redox cascade affording benzo[g]naphtho[1,2-c]cinnolinyl-7,12,14-trione (Cn·) in 69% yields, while the similar reaction with 2-hydrazinopyridine is a (7e + 7H+) oxidative cascade and furnishes N-pyridinecinnolinyl radical (PyCn·). The cascades are composed of C-N and C-C bond making reactions. The neutral even alternate arenes are always diamagnetic; thus, the isolation of Cn· and PyCn· is a breakthrough. The Cn·/Cn- and PyCn·/PyCn- redox couples are reversible, and the reaction of Cn· with [CuI(PPh3)3Cl] in the presence of hydrazine hydrate and Et3N affords a Cn- complex of copper(I), [(Cn-)CuI(PPh3)2] (1). Similar to phenalenyl radical, PyCn· exists in three redox states, PyCn+PyCn·, and PyCn-, in a smaller potential range (-0.30 V to -0.60 V vs Fc+/Fc couple) and can be used as an oxidant as well as a reductant. PyCn· acts as a catalyst for the oxidative cleavages of benzil to benzoic and 2,2′-pyridil to picolinic acids in methanol in the presence of air. The molecular and electronic structures of Cn·PyCn·, and 1·1/2MeOH were confirmed by single crystal X-ray crystallography, EPR spectroscopy, and DFT calculations.
Kinetics and Mechanism of the Oxidation of Aromatic Aldehydes by Pyridinium Fluorochromate
Agarwal, Sarswati,Chowdhury, Kakuli,Banerji, Kalyan K.
, p. 5111 - 5113 (1991)
Kinetics of oxidation of a number of ortho-, meta-, and para-substituted benzaldehydes by pyridinium fluorochromate (PFC), in dimethyl sulfoxide, were studied.The main product of oxidation is the corresponding benzoic acid.The reaction is first order with
Study of a benzoylperoxy radical in the gas phase: Ultraviolet spectrum and C6H5C(O)O2 + HO2 reaction between 295 and 357 K
Roth,Chakir,Ferhati
, p. 10367 - 10379 (2010)
This work reports the ultraviolet absorption spectrum and the kinetic determinations of the reactions 2C6H5C(O)O2 → products (I) and C6H5C(O)O2 + HO 2 → C6H5C(O)O2H + O2 (IIa), → C6H5C(O)OH + O3 (IIb), → C6H5C(O)O + OH + O2 (IIc). Experiments were performed using a laser photolysis technique coupled with UV-visible absorption detection over the pressure range of 80-120 Torr and the temperature range of 293-357 K. The UV spectrum was determined relative to the known cross section of the ethylperoxy radical C2H5O2 at 250 nm. Kinetic data were obtained by simulating the temporal behavior of the UV absorption at 245-260 nm. At room temperature, the rate constant value of reaction I (cm3 . molecule-1 . s-1) was found to be kI ) (1.5 ± 0.6) × 10-11. The Arrhenius expression for reaction II is (cm3 . molecule-1 . s -1) kII(T) ± (1.10 ± 0.20) × 10 -11 exp(364 ± 200/T). The branching ratios βO3 and βOH, respectively, of reactions IIb and IIc are evaluated at different temperatures; βO3 increases from 0.15 ± 0.05 at room temperature to 0.40 ± 0.05 at 357 K, whereas βOH remains constant at 0.20 ± 0.05. To confirm the mechanism of reaction II, a theoretical study was performed at the B3LYP/6-311++G(2d,pd) level of theory followed by CBS-QB3 energy calculations.
Highly efficient activated carbon loaded TiO2 for photo defluoridation of pentafluorobenzoic acid
Ravichandran,Selvam,Swaminathan
, p. 89 - 96 (2010)
The activated carbon loaded TiO2-P25 catalysts were prepared and characterized by diffuse reflectance spectra (DRS), FT-IR, scanning electron micrograph (SEM), X-ray diffraction (XRD) and BET surface area analysis. The photocatalytic efficiency
Effect of pyridine and tribenzylamine on the hydrolysis kinetics of benzoyl chloride in water-dioxane system
Batiha, Mohammad A.,Chizhova, Elena A.,Batiha, Marwan M.,Al-Makhadmeh, Leema A.,Rawadieh, Saleh,Alqasaimeh, Muawia,Marashli, Abdullah
, p. 1888 - 1890 (2017)
The aim of this paper was to study the effect of tribenzylamine and pyridine on the kinetics of the hydrolysis reaction of benzoyl chloride in water-dioxane solution. The benzoyl chloride and water initial concentrations were 0.005 and 1 mol/L, respectively. While, the initial concentrations of pyridine and tribenzylamine varied in the range of 0.005-0.02 mol/L and 0.007-0.014 mol/L, respectively. It was found that the addition of tribenzylamine to benzoyl chloride hydrolysis reaction has no catalytic effect and hence the rate constant can be calculated using a first-order rate equation. In the presence of pyridine, reaction obeyed second-order rate. The relationship between the reaction rate constant and pyridine initial concentration was found to be linear with a rate constant of 0.752 × 10–3 min–1.
COMPONENTS OF THE GALLS ON THE LEAVES OF PONGAMIA GLABRA: STRUCTURES OF PONGAGALLONE-A AND PONGAGALLONE-B
Gandhidasan, Rathinasamy,Neelakantan, Sthanusubramania,Raman, Pathai Venkateswara,Devaraj, Savithri
, p. 281 - 284 (1987)
The chemical examination of the galls present on the infected leaves of the plant Pongamia glabra has yielded, in addition to a number of known compounds, two new prenylated β-diketones, pongagallone-A and pongagallone-B.Evidence for their structures is presented. Key Word Index--Pongamia glabra; Leguminosae; pongagallone-A; pongagallone-B; β-diketones.
Preparation and Characterization of Destructible Surfactants
Jaeger, David A.,Frey, Moira R.
, p. 311 - 315 (1982)
Surfactants have been designed and prepared specifically for the application of surfactant-based media to organic synthesis.Condensation of 5-chloro-2-pentanone with 1,2-dodecanediol (3) yielded 2-methyl-2-(3-chloropropyl)-4-decyl-1,3-dioxolane (6), which on reaction with quinuclidine and pyridine gave 1--1-azoniabicyclooctane chloride (1) and 1-pyridinium chloride (2a), respectively.Ketal-based surfactants 1 and 2a are stable under neutral and basic conditions but readily hydrolyze under acidic conditions to 1-(4-oxopentyl)-1-azoniabicyclooctane chloride (4) and 1-(4-oxopentyl)pyridinium chloride (5), respectively, and diol 3.In catalysis of the potassium permanganate oxidation of piperonal to piperonylic acid and the aqueous sodium hydroxide hydrolysis of α,α,α-trichlorotoluene to benzoic acid, surfactants 1 and 2a are about as effective as cetyltrimethylammonium bromide.
Boron triiodide-N-N-diethylaniline complex: A new reagent for cleaving esters
Kabalka,Narayana,Reddy
, p. 1793 - 1798 (1992)
Boron triiodide N,N-diethylaniline complex was used for the hydrolysis, transesterification, and aminolysis of esters.
Biocompatible Ionic Liquid Based on Curcumin as Fluorescence Probe for Detecting Benzoyl Peroxide without the Interference of H2O2
Zhu, Qiu-Hong,Yuan, Wen-Li,Zhang, Lei,Zhang, Guo-Hao,He, Ling,Tao, Guo-Hong
, (2019)
Accurate estimation of the level of benzoyl peroxide (BPO) is of considerable significance because of its threat to humanity and environment. Several research efforts have been devoted to the detection of BPO by fluorescent method with high sensitivity and selectivity. However, it remains challenging to eliminate the interference of H2O2 due to its similar properties to BPO. In this work, the first demonstration of fluorescent and colorimetric probe for specific detection of BPO without the disturbance of H2O2 was achieved by curcumin-based ionic liquid (CIL) that possesses simple fabrication, good biocompatibility, and low cost. The fluorescence quenches and emission peak blue-shifts once the probe selectively interacts with BPO, whereas the other possible interfering agents, including H2O2, do not have this phenomenon. The probe CIL exhibits prominent sensitivity for BPO sensing and enables the detection limit at levels as ultralow as 10 nM. The local detection of BPO in practical samples is realized by visualization using a portable device derived from CIL-based liquid atomizer.
Prenylated benzoylphloroglucinols and xanthones from the leaves of garcinia oblongifolia with antienteroviral activity
Zhang, Hong,Tao, Ling,Fu, Wen-Wei,Liang, Shuang,Yang, Yi-Fu,Yuan, Qing-Hong,Yang, Da-Jian,Lu, Ai-Ping,Xu, Hong-Xi
, p. 1037 - 1046 (2014)
An acetone extract of the leaves of Garcinia oblongifolia showed antiviral activity against enterovirus 71 (EV71) using a cytopathic effect inhibition assay. Bioassay-guided fractionation yielded 12 new prenylated benzoylphloroglucinols, oblongifolins J-U (1-12), and five known compounds. The structures of 1-12 were elucidated by spectroscopic analysis including 1D- and 2D-NMR and mass spectrometry methods. The absolute configurations were determined by a combination of a Mosher ester procedure carried out in NMR tubes and ECD calculations. Compared to ribavirin (IC50 253.1 μM), compounds 1, 4, and 13 exhibited significant anti-EV71 activity in vitro, with IC50 values of 31.1, 16.1, and 12.2 μM, respectively. In addition, the selectivity indices of these compounds were 1.5, 2.4, and 3.0 in African green monkey kidney (Vero) cells, respectively.
