Aromatic sulphonation. Part XL. Rates of sulphonation ortho, meta, and para to a sulphonic acid group in methyl substituted benzenesulphonic acids

1973 ◽  
pp. 633 ◽  
Author(s):  
Ankie Koeberg-Telder ◽  
Hans Cerfontain
Keyword(s):  
Acid Group ◽  
Sulphonic Acid ◽  
Sulphonic Acid Group

Mesomeric Effect of the Sulphonic Acid Group

Nature ◽  
1953 ◽  
Vol 172 (4371) ◽  
pp. 257-258 ◽  
Author(s):  
HCH. ZOLLINGER
Keyword(s):  
Acid Group ◽  
Sulphonic Acid ◽  
Mesomeric Effect ◽  
Sulphonic Acid Group

scholarly journals 2-Sulphobenzyl, a new solubilizing and reversible protecting group for cysteine in proteins. Its scope and limitations

1979 ◽  
Vol 179 (1) ◽  
pp. 127-134 ◽  
Author(s):  
U T Rüegg ◽  
D Jarvis ◽  
J Rudinger
Keyword(s):  
Control Experiment ◽  
Acid Group ◽  
Water Soluble ◽  
Protecting Groups ◽  
Protecting Group ◽  
Isoelectric Precipitation ◽  
Mild Conditions ◽  
Sulphonic Acid Group ◽  
A Chain ◽  
Sodium Amide

S-2-Sulphobenzylcysteine and S-2-(sulphomethyl)benzylcysteine are prepared by alkylation of cysteine with omega-toluenesultone and 2,3-benzo-1,4-butanesultone respectively. Owing to the presence of the sulphonic acid group, these protected cysteine derivatives are extremely water-soluble and are stable to acid hydrolysis. The groups can be removed by treatment with sodium in liquid NH3. Reduction with tributylphosphine and simultaneous alkylation of insulin with toluenesultone under mild conditions (pH 8.3, aq. 50% propanol) gives the fully S-substituted derivatives in excellent yield; they can be separated by isoelectric precipitation of the S-sulphobenzylated B-chain. Treatment of the latter with sodium in liquid NH3 led simultaneously to the removal of the protecting groups and to the well-documented cleavage at the threonine-proline bond which can be prevented by addition of sodium amide. When deprotected A-chain was recombined with B-chain, insulin was isolated in the same yield and with the same degree of biological activity as that in the control experiment.

Diffusion of long-chain sulphonic acids*

1939 ◽  
Vol 170 (942) ◽  
pp. 415-423 ◽  
Keyword(s):  
Colloidal Particles ◽  
Colloidal Particle ◽  
Chemical Nature ◽  
Saturated Fatty Acids ◽  
Acid Group ◽  
Data Migration ◽  
Sulphonic Acid Group ◽  
Ionic Micelles ◽  
Simple Chemical ◽  
Long Chain

The straight paraffin chain sulphonic acids are of extraordinary interest on account of their simple chemical nature combined with the whole manifold of soap-like behaviour which their solutions exhibit. They are like saturated fatty acids in which the carboxy group at the end has been replaced by the true sulphonic acid group SOsH. Being free acids already, they cannot hydrolyse. They are typical colloidal electrolytes like all soaps and many modern detergents. There are at present two chief conflicting interpretations of the behaviour of colloidal electrolytes, that of McBain et al. and that of Hartley et al. McBain and Salmon (1920), in defining the class of colloidal electrolytes and reviewing the osmotic as well as the electrical behaviour together with E.M.F. data, migration, and ultrafiltration, found it necessary to postulate the existence of two kinds of colloidal particles which he names neutral micelle and ionic micelle. Hartley (1936 a, b ) and many others assume only one kind of colloidal particle with properties intermediate between McBain’s neutral and ionic micelles. However, their interpretation has been based almost solely upon conductivity data neglecting thermodynamic data. The diffusion data here to be presented cannot be explained on the basis of one kind of colloidal particle.

IONIC EFFECTS ON THE UPTAKE OF CHLOROMERCURIBENZENE-p-SULPHONIC ACID BY PANCREATIC ISLETS

1977 ◽  
Vol 86 (3) ◽  
pp. 552-560 ◽  
Author(s):  
Monica Söderberg ◽  
Inge-Bert Täljedal
Keyword(s):  
Pancreatic Islets ◽  
Islet Cell ◽  
Choline Chloride ◽  
Inorganic Ions ◽  
Sulphonic Acid ◽  
Cell Uptake ◽  
Β Cells ◽  
Sulphydryl Groups ◽  
Microdissected Pancreatic Islets ◽  
Ionic Effects

ABSTRACT Effects of inorganic ions on the uptake of chloromercuribenzene-p-sulphonic acid (CMBS) were studied in microdissected pancreatic islets of non-inbred ob/ob-mice. Na2SO4 stimulated the total islet cell uptake of CMBS but decreased the amount of CMBS remaining in islets after brief washing with L-cysteine. CaCl2 stimulated both the total and the cysteine-non-displaceable uptake; the stimulatory effect of CaCl2 on the cysteine-non-displaceable CMBS uptake was counteracted by Na2SO4. NaCl, KCl or choline chloride had no significant effect on the total islet cell uptake of CMBS, whereas LiCl was stimulatory. It is concluded that β-cells resemble erythrocytes in having a permeation path for CMBS that is inhibited by SO42−. By analogy with existing models of the erythrocyte membrane, it is suggested that the SO42−-sensitive path leads to sulphydryl groups controlling monovalent cationic permeability in β-cells.

Сatalytic Phosphorylation of Aromatic C-H Bonds: from Traditional Approaches to Electrochemistry

2019 ◽  
Vol 23 (16) ◽  
pp. 1756-1770
Author(s):  
Sofia Strekalova ◽  
Mikhail Khrizanforov ◽  
Oleg Sinyashin ◽  
Yulia Budnikova
Keyword(s):  
Organophosphorus Compounds ◽  
Normal Pressure ◽  
Acid Group ◽  
Synthetic Methods ◽  
Heteroaromatic Compounds ◽  
Anti Cancer ◽  
Phosphonic Acid Group ◽  
Traditional Approaches ◽  
Anti Hiv Agents ◽  
Anti Hiv

The interest in organophosphorus compounds with a C-P bond is due to their wide use in various fields, especially in medicine and agrochemistry. Prominent examples of anti-cancer, antibacterial, and anti-HIV agents are therapeutic candidates containing a phosphonic acid group fragment. This review provides modern synthetic methods for obtaining phosphorylated aromatic and heteroaromatic compounds with the participation of complexes and salts of various metals developed in recent years as well modern protocol - electrochemical synthesis which allows carrying out reactions at room temperature and normal pressure with no additional oxidants or bases. Herein, we demonstrate new trends and evolution of phosphorylation reactions in catalysis.

An Efficient Synthesis of 2-Substituted Quinazolin-4(3H)-ones by Using Recyclable Wang Resin Supported Sulfonic Acid Catalyst

2020 ◽  
Vol 17 ◽  
Author(s):  
Kalyani K. ◽  
Srinivasa Reddy Kallam
Keyword(s):  
Sulfonic Acid ◽  
Functional Group ◽  
Acid Catalyst ◽  
Sulphonic Acid ◽  
Isatoic Anhydride ◽  
Efficient Synthesis ◽  
Wang Resin ◽  
Polymer Supported ◽  
High Yields

Abstract:: An efficient synthesis of 2-substituted Quinazolin-4(3H)-ones has been developed from isatoic anhydride with various amidoximes by using recyclable polymer supported sulphonic acid catalyst. Excellent functional group compatibil-ity and high yields are the important features of this protocol.

Pulse polarographic study of the behaviour of some o,o'-dihydroxyazo-compounds

1989 ◽  
Vol 54 (5) ◽  
pp. 1219-1226 ◽  
Author(s):  
Enric Casassas ◽  
Miquel Esteban ◽  
Santiago Alier
Keyword(s):  
Carboxylic Acid ◽  
Reaction Mechanisms ◽  
Sulphonic Acid ◽  
Base Catalysis ◽  
Polarographic Study ◽  
Acid Base ◽  
Eriochrome Black T ◽  
Naphthoic Acid ◽  
Calcon Carboxylic Acid

The reduction of several o,o'-dihydroxyazo-compounds is studied by means of pulse polarographic techniques (DPP, NPP and RPP). The compounds studied are the following: 2-(2'-hydroxyphenylazo)-phenol (o,o'-dihydroxyazobenzene), 1-(2'-hydroxy-1'-naphthylazo)-2-naphthol-4-sulphonic acid (calcon or Eriochrome Blue Black R), 1-(2'-hydroxy-4'-sulpho-1'-naphthylazo)-2-hydroxy-3-naphthoic acid (calcon carboxylic acid), and 1-(1'-hydroxy-2'-naphthylazo)-6-nitro-2-naphthol-4-sulphonic acid (Eriochrome Black T). Correlations between Ip and Epand experimental variables (pH, T, conc.) and instrumental parameters (dropping time, t, and pulse magnitude, ΔE) are established. Reaction mechanisms formerly proposed are discussed on the basis of the new obtained results, and the ranges are defined where adsorption and/or acid-base catalysis are operative.

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