97-20-1Relevant academic research and scientific papers
Water soluble azo dyes and their synthesis and use
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, (2008/06/13)
Disclosed are water soluble azo dyes, represented by Formula I or II, and their synthesis and use. The water soluble azo dyes are synthesized by diazotizing 4-aminopyridine and coupling the resulting diazo intermediate with alkylated metanilic or orthanilic acid. To be suitable for measuring blood glucose levels, the dyes are combined with m-nitrophenyl boronic acid in an aqueous solvent. A combined ao form of the dyes with glucose shows a peak at 540 nm. At this wavelength, the absorptivity has a tendency to increase with the increasing of glucose level, which allows the measurement of blood glucose levels. wherein R has a 1-4 carbon atom length and is an alkyl, a hydroxy alkyl, a carboxyl-containing alkyl, or a sulfonyl-containing alkyl.
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.
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.
MECHANISM OF THE SULFONATION OF AROMATIC AMINES BY SULFURIC ACID AT HIGH TEMPERATURES
Khelevin, R. N.
, p. 1173 - 1178 (2007/10/02)
The kinetics of the rearrangement of unsubstituted and N-substituted phenylammonium hydrogen sulfates to the corresponding aminosulfonic acids of the benzene series were studied.The isomeric composition of the reaction products formed during the sulfonation of amines of the benzene series by various amounts of 100percent H2SO4 was also studied.The rearrangement is described by a second-order kinetic equation.Its effective rate constant at various temperatures and the activation energies were calculated.It is suggested that the sulfonation of aromatic amines by an equimolar amount of sulfuric acid at high temperatures takes place through the dissociation of the arylammonium hydrogen sulfates with the formation of arylamines and sulfuric acid and subsequent direct sulfonation of the arylamines by the sulfuric acid.
KINETICS OF THE SULFONATION OF AMINES OF THE BENZENE SERIES BY OLEUM IN THE PRESENCE OF MERCURIC SULFATE
Khelevin, R. N.
, p. 1723 - 1726 (2007/10/02)
Sulfonated mixtures with increased contents of the meta isomers are formed during the sulfonation of amine sulfates of the benzene series with oleum containing mercuric sulfate.The following mechanism is proposed for the sulfonation of the amines by oleum in the presence of mercuric sulfate.Two fast reactions take place initially, i.e., sulfonation of the unprotonated molecules of the amines of the benzene series and electrophilic mercuration of the protonated molecules of the amines with the formation of the meta-mercurio derivatives.Electrophilic substitution of the mercury by the sulfo group with formation of the meta-mercuric derivatives then occurs under the influence of the oleum.
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.
