Kinetics and Mechanism of Formation of 2,3-Disubstituted 1,4-Benzothiazines: One Pot DMSO Assisted Cyclocondensation of Bisanilino Disulphide and 1, 3-Dicarbonyls

2021 ◽  
pp. 339-344
Author(s):  
Meghmala R. Sangvikar ◽  
Gayatri M. Phadnaik ◽  
Omprakash S. Chavan
Keyword(s):  
Rate Equation ◽  
Rate Constants ◽  
Mechanism Of Formation ◽  
Reaction Conditions ◽  
One Pot ◽  
Kinetic Measurements ◽  
First Time ◽  
Kinetics Of ◽  
Order Rate Equation

The kinetics of DMSO (dimethylsulphoxide) assisted one pot cyclocondensation of bisanilino disulphide and 1,3-dicarbonyls has been investigated using spectral method. The kinetic measurements have been carried by varying media, temperature and concentration of the reactants. The assistance of DMSO is investigated. The order of reaction, effects of substituents with dicarbonyls on the rates and thermodynamic parameters has also been reported. First time reaction conditions are optimised for performing the cyclocondensation conveniently and rapidly. Probably mechanism has been proposed and order of reaction was determined on the basis of rate expression and was in agreement with second order rate equation, used for the determination of rate constants.

Determination of the Nucleophilicity of Tricarbonyliron Coordinated Cyclohepta-1,3,5-triene

1999 ◽  
Vol 64 (11) ◽  
pp. 1770-1779 ◽  
Author(s):  
Herbert Mayr ◽  
Karl-Heinz Müller
Keyword(s):  
Gibbs Energy ◽  
Ambient Temperature ◽  
Rate Constants ◽  
Second Order ◽  
Order Rate ◽  
Electrophilic Additions ◽  
Kinetics Of

The kinetics of the electrophilic additions of four diarylcarbenium ions (4a-4d) to tricarbonyl(η4-cyclohepta-1,3,5-triene)iron (1) have been studied photometrically. The second-order rate constants match the linear Gibbs energy relationship log k20 °C = s(E + N) and yield the nucleophilicity parameter N(1) = 3.69. It is concluded that electrophiles with E ≥ -9 will react with complex 1 at ambient temperature.

The kinetics of the decarboxylation of β-resorcylic acid in catechol

1976 ◽  
Vol 29 (2) ◽  
pp. 443 ◽  
Author(s):  
MA Haleem ◽  
MA Hakeem
Keyword(s):  
Rate Equation ◽  
Kinetic Data ◽  
Reaction Rate ◽  
Complex Mechanism ◽  
First Order ◽  
Absolute Reaction Rate ◽  
First Time ◽  
Kinetics Of ◽  
Absolute Reaction ◽  
Reaction Rate Equation

Kinetic data are reported for the decarboxylation of β-resorcylic acid in resorcinol and catechol for the first time. The reaction is first order. The observation supports the view that the decomposition proceeds through an intermediate complex mechanism. The parameters of the absolute reaction rate equation are calculated.

scholarly journals Determination of the steady-state turnover rates of the metabolically active pools of phosphatidylinositol 4-phosphate and phosphatidylinositol 4,5-bisphosphate in human erythrocytes

1989 ◽  
Vol 259 (3) ◽  
pp. 893-896 ◽  
Author(s):  
C E King ◽  
P T Hawkins ◽  
L R Stephens ◽  
R H Michell
Keyword(s):  
Steady State ◽  
Rate Constants ◽  
Human Erythrocytes ◽  
Turnover Rates ◽  
Metabolic Fluxes ◽  
Metabolic Pool ◽  
Phosphatidylinositol 4 ◽  
Kinetics Of ◽  
Phosphate Groups

When intact human erythrocytes are incubated at metabolic steady state in a chloride-free medium containing [32P]Pi, there is rapid labelling of the gamma-phosphate of ATP, followed by a slower labelling of the monoester phosphate groups of phosphatidylinositol 4-phosphate (PtdIns4P) and phosphatidylinositol 4,5-bisphosphate [PtdIns(4,5)P2] [King, Stephens, Hawkins, Guy & Michell (1987) Biochem. J. 244, 209-217]. We have analysed the early kinetics of the labelling of these phosphate groups, in order to determine: (a) the steady-state rates of the interconversions of phosphatidylinositol, PtdIns4P and PtdIns(4,5)P2; and (b) the fractions of the total cellular complement of PtdIns4P and PtdIns(4,5)P2 that participate in this steady-state turnover. The experimental data most closely fit a pattern of PtdIns4P and PtdIns(4,5)P2 turnover in which one-quarter of the total cellular complement of each lipid is in the metabolic pool that participates in rapid metabolic turnover, with rate constants of 0.028 min-1 for the interconversion of PtdIns and PtdIns4P, and of 0.010 min-1 for the PtdIns4P/PtdIns(4,5)P2 cycle. These rate constants represent metabolic fluxes of approx. 2.1 nmol of lipid/h per ml of packed erythrocytes between PtdIns and PtdIns4P and of approx. 5.7 nmol/h per ml of cells between PtdIns4P and PtdIns(4,5)P2.

An experimental and theoretical study of the kinetics of the reaction between 3-hydroxy-3-methyl-2-butanone and OH radicals

RSC Advances ◽  
2015 ◽  
Vol 5 (34) ◽  
pp. 26559-26568 ◽  
Author(s):  
Angappan Mano Priya ◽  
Gisèle El Dib ◽  
Lakshmipathi Senthilkumar ◽  
Chantal Sleiman ◽  
Alexandre Tomas ◽  
...  
Keyword(s):  
Rate Constants ◽  
Theoretical Study ◽  
Oh Radicals ◽  
First Time ◽  
Kinetics Of

Absolute experimental and theoretical rate constants are determined for the first time for the reaction of 3-hydroxy-3-methyl-2-butanone with OH as a function of temperature. The atmospheric implications are discussed.

Studies on metal hydroxy compounds. X. Thermal analyses, decomposition kinetics, and infrared spectra of lead halide (Cl, Br, I) derivatives

1970 ◽  
Vol 48 (16) ◽  
pp. 2617-2622 ◽  
Author(s):  
P. Ramamurthy ◽  
E. A. Secco ◽  
M. Badri
Keyword(s):  
Infrared Spectra ◽  
Rate Equation ◽  
Thermal Analyses ◽  
Decomposition Reaction ◽  
Diffusion Type ◽  
Type Rate ◽  
Hydroxy Compounds ◽  
Kinetics Of ◽  
Lead Halide ◽  
Order Rate Equation

The thermal analyses, thermogravimetry (TG), and differential thermal analysis (DTA) of PbOHCl, PbOHBr, and PbOHI reveal that the initial mode of decomposition is via dehydroxylation. Calorimetric measurements along with related enthalpy values for the decomposition reaction are given.The infrared spectra of these compounds are interpreted in terms of folded bands of (PbOH+)n tied together by halide ions consistent with their crystal structures.The kinetics of thermal decomposition of lead hydroxyhalides follow a diffusion-type rate equation which is in contrast to the simple first-order rate equation observed for most Cd, Zn, and Cu compounds. These two distinct rates are interpreted in terms of mobile OH or H species in the dehydroxylation step.

THE REDUCTION OF CYTOCHROMEcBY HYDROQUINONE

1963 ◽  
Vol 41 (1) ◽  
pp. 231-237 ◽  
Author(s):  
G. R. Williams
Keyword(s):  
Reaction Mechanism ◽  
Ionic Strength ◽  
Rate Equation ◽  
Second Order ◽  
Order Rate ◽  
Ferricytochrome C ◽  
Kinetics Of ◽  
Kinetics Of Reduction ◽  
Order Rate Equation

The kinetics of reduction of ferricytochrome c by hydroquinone have been studied. The reaction does not conform to a simple second-order rate equation and it is demonstrated that the deviations are brought about by the presence of p-quinone, one of the products of the reaction. The accelerating effect of p-quinone is explained tentatively on the basis of an involvement of the semi-quinone. The effects on the reaction of pH, ionic strength, and temperature are reported and used to suggest features of the reaction mechanism.

Neodymium-Promoted Highly Selective Carbon–Carbon Double Bond Formation of Ketones with Allyl Halides in the Presence of Diethyl Phosphite

Synthesis ◽  
2020 ◽  
Vol 52 (22) ◽  
pp. 3446-3451
Author(s):  
Songlin Zhang ◽  
Dengbing Xie ◽  
Yiqiong Wang ◽  
Bo Yang
Keyword(s):  
Double Bond ◽  
Bond Formation ◽  
Point Of View ◽  
Diethyl Phosphite ◽  
Reaction Conditions ◽  
One Pot ◽  
Mild Conditions ◽  
Carbon Double Bond ◽  
Allyl Halides ◽  
First Time

The carbon–carbon double bond formation via neodymium-mediated Barbier-type reaction of ketones and allyl halides in the presence of diethyl phosphite is reported for the first time. The reaction is highly α-regioselective and was conveniently carried out under mild conditions in a one-pot fashion. From a synthetic point of view, a series of conjugated alkenes were obtained in moderate to good yields in this one-pot reaction with feasible reaction conditions.

KINETICS OF THE AQUEOUS ALKALINE HOMOGENOUS HYDROLYSIS OF HIGH EXPLOSIVE 1, 3,5,7-TETRAAZA- 1, 3,5,7-TETRANITROCYCLOOCTANE (HMX)

1994 ◽  
Vol 30 (3) ◽  
pp. 53-61 ◽  
Author(s):  
Harro M. Heilmann ◽  
Michael K. Stenstrom ◽  
Rolf P. X. Hesselmann ◽  
Udo Wiesmann
Keyword(s):  
Temperature Dependence ◽  
Alkaline Hydrolysis ◽  
Rate Constants ◽  
Elevated Temperatures ◽  
Second Order ◽  
Order Rate ◽  
Subsequent Calculation ◽  
Kinetics Of ◽  
Hydrolysis Of ◽  
Order Rate Equation

In order to get basic data for the design of a novel treatment scheme for high explosives we investigated the kinetics for the aqueous alkaline hydrolysis of 1,3,5,7-tetraaza-1,3,5,7-tetranitrocyclooctane (HMX) and the temperature dependence of the rate constants. We used an HPLC procedure for the analysis of HMX. All experimental data could be fit accurately to a pseudo first-order rate equation and subsequent calculation of second-order rate constants was also precise. Temperature dependence could be modeled with the Arrhenius equation. An increase of 10°C led to an average increase in the second-order rate constants by the 3.16 fold. The activation energy of the second-order reaction was determined to be 111.9 ±0.76 kJ·moJ‒1. We found the alkaline hydrolysis to be rapid (less than 2.5% of the initial HMX-concentration left after 100 minutes) at base concentrations of 23 mmol oH‒/L and elevated temperatures between 60 and 80°C.

Kinetics and Modelling of Bulk and Solution Diallyl Terephthalate Polymerization

2006 ◽  
Vol 4 (1) ◽  
Author(s):  
Iztok Hace
Keyword(s):  
Kinetic Model ◽  
Kinetic Parameters ◽  
Rate Constants ◽  
Chain Transfer ◽  
Average Molecular Weight ◽  
Propagation Rate ◽  
Reaction Conditions ◽  
Diffusion Limitations ◽  
Kinetics Of ◽  
Dicyclohexyl Peroxydicarbonate

Free radical polymerization kinetics of diallyl terephthalate (DAT) in solution was investigated with two different peroxide initiators: dicyclohexyl peroxydicarbonate (CHPC) and benzoyl peroxide (BPO) in temperature range from 50°C to 110°C, where ortho-xylene was used as a solvent. Conversion points were measured using Fourier Transform Infrared (FTIR) measurements. Previously developed kinetic model for bulk DAT polymerization, was extended to solution DAT polymerization. The ratio of solvent chain - transfer rate constants to propagation rate constants of the polymerization system were found between 1.25 10-4 to 1.68 10-4 for various reaction conditions. They were obtained using the calculated initial polymerization rates and the number average molecular weight measurements made by GPC. The effect of different solvent fractions and initiator concentrations on the diffusion limitations were investigated. Only two kinetic parameters, kpd0 and ktd0 were obtained by fitting the kinetic model onto measured conversions for various reaction conditions at 0.2, 0.5 and 0.8 solvent fractions. Thus obtained kpd0 and ktd0 kinetic parameters were extrapolated to zero solvent fractions and from obtained values of kinetic parameters the conversion points for bulk DAT polymerization were calculated and compared to measured conversion points.

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