24447-99-2Relevant academic research and scientific papers
ISOMERIC TRANSFORMATIONS OF AMINOSULFONIC ACIDS OF THE BENZENE SERIES IN MIXTURES OF SULFURIC AND ACETIC ACIDS
Khelevin, R. N.
, p. 132 - 137 (2007/10/02)
The isomerization rate of aminosulfonic acids in anhydrous binary mixtures of sulfuric and acetic acids is lower than in aqueous sulfuric acid solutions but higher than in 100percent sulfuric acid.This is explained by the differences in the structure and activity of the proton carriers during desulfonation.The rate of transformation of the labile isomers into the meta isomers increases with increase in the acidity of the medium, and this is due to the increase in the resulfonation rate of the protonating molecules of the amines formed during the desulfonation of the aminosulfonic acids.The effect of mercuric sulfate on the isomeric transformations of aminosulfonic acids is explained by the mercuration of the protonated molecules of the amines, which takes place at higher rates than their sulfonation and leads to the formation of the meta-mercury derivatives of the amines.The latter are than converted into the m-aminosulfonic acids by the action of concentrated sulfuric acid.
KINETICS OF SULFONATION OF AMINES OF THE BENZENE SERIES WITH SULFUR TRIOXIDE
Khelevin, R. N.
, p. 535 - 539 (2007/10/02)
The sulfonation of amines of the benzene series with sulfur trioxide in dichloroethane is described by a third-order kinetic equation for an irreversible process, and first order is observed with respect to the compound being sulfonated and second with respect to the sulfur trioxide.The unprotonated molecules of the amines undergo sulfonation, and this leads to the production of the para-aminosulfonic acids with small amounts of the ortho isomers.The reaction mechanism involves electrophilic reaction of the unprotonated amine molecule with the sulfur trioxide dimer S2O6 and subsequent dissociation of the obtained pyrosulfonate with the production of the amino sulfonic acid and sulfur trioxide.
KINETICS OF THE SULFONATION OF AMINES OF THE BENZENE SERIES BY CHLOROSULFONIC ACID
Khelevin, R. N.
, p. 1709 - 1713 (2007/10/02)
The kinetics of the sulfonation of amines of the benzene series by an equimolar amount of chlorosulfonic acid in o-dichlorobenzene were studied.It was shown that the sulfonation of aniline and N-alkylanilines is described by a second-order kinetic equation for irreversible reactions.The sulfonation of N,N-dialkylanilines by chlorosulfonic acid is described by a first-order kinetic equation for irreversible reactions.The observed relationships are explained by different mechanism for the sulfonation of amines of the benzene series by chlorosulfonic acid.The sulfonation of aniline and N-alkalynilines takes place by direct reaction between the unprotonated molecules of the amines and the HSO3(1+) ion, whereas in the reaction of chlorosulfonic acid with N,N-dialkylanilines complexes of the N,N-dialkylanilines with sulfur trioxide (dialkylanilinesulfotrioxides) are formed initially and then rearrange to the corresponding para-aminosulfonic acids.
REARRANGEMENT OF PHENYL- AND N-ALKYLPHENYLAMMONIUM HYDROGEN SULFATES IN ORGANIC SOLVENTS
Khelevin, R. N.
, p. 1906 - 1911 (2007/10/02)
The kinetics of the rearrangement of phenyl- and N-alkylphenylammonium hydrogen sulfates in halogen-containing organic solvents were investigated in closed systems and with the removal of the water produced in the reaction.The isomeric composition of the obtained aminobenzenesulfonic acids was also studied.The rearrangement is described by a second-order kinetic equation.The reaction mechanism involves thermal dissociation of the phenyl- and N-alkylphenylammonium hydrogen sulfates at high temperatures to amines (bases) and sulfuric acid, followed by direct sulfonation of the amines (bases) by the sulfuric acid with the formation mostly of para-aminosulfonic acids of the benzene series.
KINETIC OF THE SULFONATION OF AMINES OF THE BENZENE SERIES WITH SULFURIC ACID
Khelevin, R. N.
, p. 339 - 347 (2007/10/02)
The kinetics of the sulfonation of primary, secondary, and tertiary amines of the benzene series with 80-99.7percent sulfuric acid were investigated.It was shown that the unprotonated and protonated forms of the amines, which are present in equilibrium, undergo sulfonation.The effective reaction rate constants and the activation energies for the sulfonation of the unprotonated and protonated molecules of the amines were calculated.The reaction mechanism and the structure of the transition state are discussed.
ISOMERIZATION OF AMINOSULFONIC ACIDS OF THE BENZENE SERIES IN THE PRESENCE OF MERCURIC SULFATE
Khelevin, R.N.
, p. 720 - 725 (2007/10/02)
The isomerization of aminosulfonic acids of the benzene series in 85, 90, and 95percent sulfuric acid at 180, 190, and 200 deg C in the presence of mercuric sulfate was investigated.Mercuric sulfate accelerates the isomerization of ortho- and para-aminosulfonic acids of the benzene series to the meta isomers.Here the para aminosulfonic acids are converted irreversibly into the meta-aminosulfonic acids.The ortho isomers initially form a mixture of the meta and para isomers.Subsequently the para isomers are converted into the kintically more stable meta isomers.The effective rate constants for the isomerization of the aminosulfonic acids and also the activation energies were calculated.The effect of mercuric sulfate on the isomerization of the aminosulfonic acid is explained by the mercuration of the protonated arylamines, which takes place at higher rates compared with the sulfonation rates.The meta-mercurated derivatives are converted by the action of concentrated sulfuric acid into meta-aminobenzenesulfonic acids.
