On the positional reactivity order in the sulfuric acid sulfonation of the two naphthalenesulfonic acids

1983 ◽  
Vol 61 (7) ◽  
pp. 1453-1455 ◽  
Author(s):  
Peter de Wit ◽  
Hans Cerfontain
Keyword(s):  
Sulfuric Acid ◽  
Sulfonic Acid ◽  
Steric Effects ◽  
Disulfonic Acid ◽  
Acid Mixture ◽  
Aqueous Sulfuric Acid ◽  
The Difference ◽  
Reactivity Order ◽  
Electronic And Steric Effects

The sulfonation in 98.5% H2SO4 at 25.0 °C of naphthalene-1-sulfonic acid yields 58% 1,5-, 32% 1,6-, and 10% 1,7-disulfonic acids and that of the 2-sulfonic acid 4% 1,3-, 74% 1,6-, 18% 1,7-, and 4% 2,6- + 2,7-disulfonic acids. Further sulfonation of the latter disulfonic acid mixture in 105.2% H2SO4 at 25.0 °C yields 78% 1,3,6- and 12% 1,3,5- + 1,3,7-trisulfonic acids. Reaction of naphthalene-1,5-disulfonic acid with 105.2% H2SO4 at 25 °C yields 5-sulfonaphthalene-1-sulfonic anhydride.Partial rate factors for the sulfonation of naphthalene-1- and -2-sulfonate in highly concentrated aqueous sulfuric acid (where the sulfonating entity is H2S2O7) are reported. They are discussed in terms of the difference in the reactivity of the α- and β-positions of the naphthalene skeleton and the electronic and steric effects of the sulfonate substituent already present.

Meso and β-pyrrole sulfonated porphyrins obtained by sulfonation of 5,15-bis(phenyl)porphyrin

2000 ◽  
Vol 04 (05) ◽  
pp. 564-568 ◽  
Author(s):  
HECTOR GARCIA-ORTEGA ◽  
JOSEP M. RIBO
Keyword(s):  
Sulfuric Acid ◽  
Sodium Salt ◽  
Good Yield ◽  
Sulfonic Acid ◽  
Disulfonic Acid ◽  
Acid Mixture ◽  
Sodium Salts ◽  
Concentrated Sulfuric Acid ◽  
Trisodium Salt

The sulfonation of 5,15-bis(phenyl)porphyrin (DPP) in concentrated sulfuric acid results in substitution on the β-pyrrolic positions and the expected sulfonation on the para positions of the phenyl substituents. The sodium salt of 5,15-bis(4-sulfonatophenyl)porphyrin-2-sulfonic acid ( S 3 DPP ) was prepared in good yield, the sodium salts of 5,15-bis(4-sulfonatophenyl)porphyrin ( S 2 A DPP ), 5-phenyl-15-(4-sulfonatophenyl)porphyrin-2-sulfonic acid ( S 2 B DPP ) and 15-phenyl-5-(4-sulfonatophenyl)porphyrin ( S 1 A DPP ) were isolated, and 5,15-bis(phenyl)porphyrin-2-sulfonic acid ( S 1 B DPP ) was detected in a mixture with S 1 A DPP . The β-pyrrole sulfonato substituents are stable and their potential synthetic use is shown by the preparation of the trisodium salt of 10-bromo-5,15-bis(4-sulfonatophenyl)porphyrin-2-sulfonic acid ( BrS 3 DPP ) by NBS bromination of S 3 DPP . In a methanol/sulfuric acid mixture the sulfonation occurs on the meso positions, and the tetrasodium salt of 10,20-bis (4-sulfonatophenyl)porphyrin-5,15-disulfonic acid ( S 4 DPP ) was obtained.

Ortho Effect in Dissociation of Substituted N-Phenylbenzenesulfonamides

2001 ◽  
Vol 66 (9) ◽  
pp. 1380-1392 ◽  
Author(s):  
Jiří Nádvorník ◽  
Miroslav Ludwig
Keyword(s):  
Experimental Data ◽  
Latent Variables ◽  
Dissociation Constants ◽  
Substituent Effects ◽  
Principal Component ◽  
Steric Effects ◽  
Deviation Analysis ◽  
Acid Base Equilibrium ◽  
The Difference ◽  
Electronic And Steric Effects

Twenty-five 2,2'-disubstituted N-phenylbenzenesulfonamides (2-X-C6H4SO2NHC6H4-Y-2') were synthesised and their purity checked by elemental analysis. This set of model substrates involved all possible combinations of methoxy, methyl, hydrogen, chloro, and nitro substituents. The dissociation constants of the sulfonamides were determined by potentiometric titration in methanol, pyridine, dimethyl sulfoxide, N,N-dimethylformamide, acetone, and acetonitrile. The dissociation constants pKHA obtained were correlated with various sets of substituent constants describing electronic and steric effects of the substituents, and the statistically treated data were used to discuss the contribution of the substituent effects in the dissociation and the difference between the effects transmitted from the two rings. A linear regression model explaining 99% of the variability of experimental data in all the solvents has been found and discussed. Moreover, the experimental data were also interpreted by the methods using latent variables, the principal component analysis (PCA) and conjugated deviation analysis (CDA), and two latent variables were shown to be statistically significant in the description of dissociation. The first obviously describes common action of electronic and steric effects of substituents; the other probably concerns a combined effect of substituent and solvent on the position of acid-base equilibrium.

Thiohydantoins. X. Kinetic Studies of the Acid Hydrolysis of 1-Acyl-2-thiohydantoins

1972 ◽  
Vol 50 (23) ◽  
pp. 3767-3779 ◽  
Author(s):  
Wayne Irvine Congdon ◽  
John Thomas Edward
Keyword(s):  
Sulfuric Acid ◽  
Carboxylic Acid ◽  
Acid Hydrolysis ◽  
Kinetic Studies ◽  
Steric Effects ◽  
Aqueous Sulfuric Acid ◽  
Hydrolysis Of

The rates of hydrolysis of 22 1-acyl-2-thiohydantoins in aqueous sulfuric acid to give 2-thiohydantoin and a carboxylic acid have been determined. In 0–90% sulfuric acid, hydrolysis takes place by an A-2 mechanism, and the rate reaches a maximum in about 70% acid. In acid more concentrated than about 90%, hydrolysis takes place by an A-1 mechanism, and the rate increases monotonically. Evidence for the two mechanisms comes from Yates r and Bunnett-Olsen [Formula: see text] parameters; from entropies of activation; from pσ and pσ+ relations; and from steric effects.

scholarly journals Aqueous Sulfuric Acid as the Mobile Phase in Cation Ion Chromatography for Determination of Histamine, Putrescine, and Cadaverine in Fish Samples

2011 ◽  
Vol 94 (2) ◽  
pp. 565-571
Author(s):  
Benjamin S Liao ◽  
Jackie Sram ◽  
Teresa T Cain ◽  
Kenneth R Halcrow
Keyword(s):  
Sulfuric Acid ◽  
Biogenic Amines ◽  
Ion Chromatography ◽  
Mobile Phase ◽  
Mobile Phase Flow Rate ◽  
Aqueous Sulfuric Acid ◽  
Peak Separation ◽  
Fish Samples ◽  
Standard Calibration ◽  
The Difference

Abstract Aqueous sulfuric acid can be used as the mobile phase in cation ion chromatography to separate the three biogenic amines, putrescine, cadaverine, and histamine, from fish. Various concentrations of aqueous sulfuric acid were investigated to optimize the separation of these three biogenic amines. Aqueous sulfuric acid (5.0 mM) was found to be optimum for the separation and was used to determine the three biogenic amines in fish. The LOQ, defined as the lowest level of the standard calibration curve, was 0.055 ppm (equivalent to 0.55 g/g sample) for putrescine, 0.05 ppm (equivalent to 0.5 g/g sample) for cadaverine, and 1.0 ppm (equivalent to 10 g/g sample) for histamine. From statistical analysis of the LOQ, the method detection limit was 0.003 ppm for putrescine, 0.009 ppm for cadaverine, and 0.16 ppm for histamine. For sample preparation, the fish was composited, homogenized in methanolwater (75 25, v/v), incubated for 15 min at 60C, and centrifuged. The sample solution was micron-filtered before injection. The mobile phase flow rate was 0.8 mL/min under isocratic conditions at room temperature (1525C). The three biogenic amines were separated in the order of increasing retention time, i.e., putrescine, cadaverine, and histamine, within 30 min. The chromatograms showed complete peak separation of the three amines regardless of the difference in fish matrixes.

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