Isoxazoles. 4. Hydrolysis of sulfonamide isoxazole derivatives in concentrated sulfuric acid solutions. A new treatment of the medium effects on protonation equilibriums and reaction rates

1978 ◽  
Vol 43 (6) ◽  
pp. 1173-1177 ◽  
Author(s):  
Ruben H. Manzo ◽  
Maria Martinez de Bertorello
Keyword(s):  
Sulfuric Acid ◽  
Reaction Rates ◽  
Acid Solutions ◽  
Medium Effects ◽  
Concentrated Sulfuric Acid ◽  
New Treatment ◽  
Sulfuric Acid Solutions ◽  
Hydrolysis Of ◽  
Isoxazole Derivatives

Substituent Effects on the Hydrolysis of p-Substituted Benzonitriles in Sulfuric Acid Solutions at (25.0± 0.1) °C

2008 ◽  
Vol 63 (9) ◽  
pp. 603-608 ◽  
Author(s):  
Khamis A. Abbas
Keyword(s):  
Sulfuric Acid ◽  
Rate Constants ◽  
Inductive Effect ◽  
Substituent Effects ◽  
Acid Solutions ◽  
Rate Determining Step ◽  
Inductive Effects ◽  
High Concentrations ◽  
Sulfuric Acid Solutions ◽  
Hydrolysis Of

The rate constants of the hydrolysis of p-substituted benzonitriles with sulfuric acid solutions (18.2 M to 10 M) have been determined spectrophotometrically at (25.1±0.1) °C. It was found that the catalytic activity of sulfuric acid was strongly inhibited by water. The logarithms of the observed rate constants were correlated with different substituent inductive (localized) and resonance (delocalized) constants. The results of the correlation studies indicated that the rate-determining step of the hydrolysis of benzonitriles in 18.2 M sulfuric acid was the addition of a nucleophile, and the hydrolysis was clearly enhanced by the electron-withdrawing inductive effect, while the rate-determining step of the hydrolysis of p-substituted benzonitriles in 10.0 M sulfuric acid was most probably the protonation of benzonitriles, and the rate constants increased by both electron-donating resonance and inductive effects. A mixture of the two mechanisms most probably occurred in 15.3 to 17.0 M sulfuric acid. HSO4 − rather thanwater most probably acted as nucleophile in the hydrolysis of benzonitriles especially at high concentrations of sulfuric acid solutions.

Tribocorrosion behavior of Ti3SiC2 in the dilute and concentrated sulfuric acid solutions

Wear ◽  
2010 ◽  
Vol 269 (1-2) ◽  
pp. 50-59 ◽  
Author(s):  
Shufang Ren ◽  
Junhu Meng ◽  
Jingbo Wang ◽  
Jinjun Lu ◽  
Shengrong Yang
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Concentrated Sulfuric Acid ◽  
Sulfuric Acid Solutions

Thermodynamic modelling of concentrated sulfuric acid solutions

Calphad ◽  
2012 ◽  
Vol 38 ◽  
pp. 168-176 ◽  
Author(s):  
Hannu Sippola
Keyword(s):  
Sulfuric Acid ◽  
Thermodynamic Modelling ◽  
Acid Solutions ◽  
Concentrated Sulfuric Acid ◽  
Sulfuric Acid Solutions

Oxidation of aliphatic secondary alcohols by chromium(VI) in concentrated sulfuric acid solutions

1967 ◽  
Vol 32 (9) ◽  
pp. 2868-2871 ◽  
Author(s):  
Donald Garry Lee ◽  
Ross Stewart
Keyword(s):  
Sulfuric Acid ◽  
Secondary Alcohols ◽  
Acid Solutions ◽  
Chromium Vi ◽  
Concentrated Sulfuric Acid ◽  
Sulfuric Acid Solutions

Pulse radiolysis study of concentrated sulfuric acid solutions. Formation mechanism, yield and reactivity of sulfate radicals

1992 ◽  
Vol 88 (12) ◽  
pp. 1653 ◽  
Author(s):  
Pei-Yun Jiang ◽  
Yosuke Katsumura ◽  
Ryuji Nagaishi ◽  
Masahumi Domae ◽  
Kenichi Ishikawa ◽  
...  
Keyword(s):  
Sulfuric Acid ◽  
Formation Mechanism ◽  
Pulse Radiolysis ◽  
Acid Solutions ◽  
Sulfate Radicals ◽  
Concentrated Sulfuric Acid ◽  
Sulfuric Acid Solutions

DECOMPOSITION OF DITHIOCARBAMATES. III. ETHYLDITHIOCARBAMIC ACID IN CONCENTRATED SULFURIC ACID SOLUTIONS

1972 ◽  
Vol 1 (2) ◽  
pp. 159-162 ◽  
Author(s):  
Fumitaka Takami ◽  
Shigeru Wakahara ◽  
Takashi Maeda
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Concentrated Sulfuric Acid ◽  
Sulfuric Acid Solutions

The excess acidity method. The basicities, and rates and mechanisms of enolization, of some acetophenones and acetone, in moderately concentrated sulfuric acid

1979 ◽  
Vol 57 (22) ◽  
pp. 2952-2959 ◽  
Author(s):  
Robin A. Cox ◽  
Clinton R. Smith ◽  
Keith Yates
Keyword(s):  
Sulfuric Acid ◽  
Function Method ◽  
Water Molecules ◽  
Acid Solutions ◽  
Linear Free Energy ◽  
Rate Determining Step ◽  
Energy Relationships ◽  
Concentrated Sulfuric Acid ◽  
Sulfuric Acid Solutions ◽  
Medium Acidity

The X-function method has been used to evaluate the basicities of six nuclear-substituted acetophenones and acetone, using a combination of new measurements and literature data; the protonation [Formula: see text] of acetone was found to be −5.37. The same method, which involves the excess medium acidity, when used to analyze the enolization rate constants obtained from the measured bromination rates, shows that most of the acetophenones enolize by an A-2 process involving two water molecules in the rate-determining step. Observed linear free energy relationships for the basicities and the enolization rates imply a relatively early transition state for the enolization. Acetone was found to enolize by a similar mechanism in sulfuric acid solutions more dilute than 81% w/w, but at higher acidities bisulfate ion was the preferred base. The mechanistic behaviour of 4-nitroacetophenone was found to be different, not A-2 but either A-1 or A-SE2.

ChemInform Abstract: Sulfonation of β-Carbolines in Concentrated Sulfuric Acid Solutions.

ChemInform ◽  
1989 ◽  
Vol 20 (6) ◽  
Author(s):  
M. A. MUNOZ ◽  
M. BALON ◽  
C. CARMONA ◽  
J. HIDALGO ◽  
M. LOPEZ POVEDA
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Concentrated Sulfuric Acid ◽  
Sulfuric Acid Solutions

Solubility of vanadyl sulfate in concentrated sulfuric acid solutions

1998 ◽  
Vol 72 (2) ◽  
pp. 105-110 ◽  
Author(s):  
F Rahman ◽  
M Skyllas-Kazacos
Keyword(s):  
Sulfuric Acid ◽  
Vanadyl Sulfate ◽  
Acid Solutions ◽  
Concentrated Sulfuric Acid ◽  
Sulfuric Acid Solutions
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