The Mechanism of Bromination of 2(1H)-Pyrimidinone, its N-Methyl and N,N′-Dimethyl Derivatives in Aqueous Acidic Solution

1974 ◽  
Vol 52 (3) ◽  
pp. 451-457 ◽  
Author(s):  
Oswald S. Tee ◽  
Sujit Banerjee
Keyword(s):  
Sulfuric Acid ◽  
Acidic Solution ◽  
Acid Solutions ◽  
Aqueous Sulfuric Acid ◽  
Acid Catalyzed ◽  
Aqueous Acidic Solution ◽  
Sulfuric Acid Solutions

Rates of bromination at the 5-positions of the title compounds have been measured in aqueous sulfuric acid solutions. The reaction involves a rapid irreversible formation of a 5-bromo-4,6-dihydroxy-hexahydro-2-oxopyrimidine which undergoes slow acid-catalyzed conversion to the corresponding 5-bromopyrimidinone. If excess bromine is present the latter product reacts further to produce a 5,5-dibromo-4,6-dihydroxyhexahydropyrimidine.

Mechanistic variation in the reactions of substituted acetamides in aqueous sulfuric acid

1984 ◽  
Vol 62 (11) ◽  
pp. 2401-2414 ◽  
Author(s):  
Linda M. Druet ◽  
Keith Yates
Keyword(s):  
Sulfuric Acid ◽  
Water Molecules ◽  
Acid Solutions ◽  
Reaction Products ◽  
Aqueous Sulfuric Acid ◽  
Rate Determining Step ◽  
Wide Range ◽  
Acid Catalyzed ◽  
Catalyzed Reactions ◽  
Sulfuric Acid Solutions

The acid-catalyzed reactions of acetamide 1, N-tert-butylacetamide 2, and several p-substituted N-benzylacetamides (3 = H, 4 = CH3, 5 = OCH3, 6 = Cl, 7 = NO2) have been studied as a function of acidity and temperature over a wide range of aqueous sulfuric acid solutions (0–91%). Analysis of the reaction products and rate–acidity profiles revealed that four different mechanisms are operative over different acidity regions depending on the structure of the substrate. These are: two A-2 hydrolysis mechanisms with N-acyl fission of the substrate (with participation of one or several water molecules in the rate-determining step); A-1 hydrolysis with N-alkyl fission; and sulfonation, followed by hydrolysis. These conclusions are supported by three complementary and detailed kinetic treatments based on the hydration parameter, transition state activity coefficient, and excess acidity approaches. The acidity domains of each mechanism have been established for each substrate. The mechanistic conclusions are fully supported by the different values of ΔH‡ and ΔS‡ obtained in different regions of acidity.

Electrochemistry of Gold in Aqueous Sulfuric Acid Solutions under Neural Stimulation Conditions

2005 ◽  
Vol 152 (7) ◽  
pp. E212 ◽  
Author(s):  
Daniel R. Merrill ◽  
Ionel C. Stefan ◽  
Daniel A. Scherson ◽  
J. Thomas Mortimer
Keyword(s):  
Sulfuric Acid ◽  
Neural Stimulation ◽  
Acid Solutions ◽  
Aqueous Sulfuric Acid ◽  
Sulfuric Acid Solutions

scholarly journals Uptake of hypobromous acid (HOBr) by aqueous sulfuric acid solutions: low-temperature solubility and reaction

2005 ◽  
Vol 5 (6) ◽  
pp. 1577-1587 ◽  
Author(s):  
L. T. Iraci ◽  
R. R. Michelsen ◽  
S. F. M. Ashbourn ◽  
T. A. Rammer ◽  
D. M. Golden
Keyword(s):  
Sulfuric Acid ◽  
Stratospheric Aerosol ◽  
Acid Solutions ◽  
Aerosol Composition ◽  
Gaseous Products ◽  
Aqueous Sulfuric Acid ◽  
Key Species ◽  
Hypobromous Acid ◽  
Equilibrium Concentrations ◽  
Sulfuric Acid Solutions

Abstract. Hypobromous acid (HOBr) is a key species linking inorganic bromine to the chlorine and odd hydrogen chemical families. We have measured the solubility of HOBr in 45-70wt% sulfuric acid solutions representative of upper tropospheric and lower stratospheric aerosol composition. Over the temperature range 201-252 K, HOBr is quite soluble in sulfuric acid, with an effective Henry's law coefficient, H*=104-107mol L-1atm-1. H* is inversely dependent on temperature, with ΔH=-45.0±5.4 kJ mol-1 and ΔS=-101±24 J mol-1K-1 for 55-70wt% H2SO4 solutions. Our study includes temperatures which overlap both previous measurements of HOBr solubility. For uptake into 55-70wt% H2SO4, the solubility is described by log H*=(2349±280)/T-(5.27±1.24). At temperatures colder than ~213K, the solubility of HOBr in 45wt% H2SO4 is at least a factor of five larger than in 70wt% H2SO4, with log H*=(3665±270)/T-(10.63±1.23). The solubility of HOBr is comparable to that of HBr, indicating that upper tropospheric and lower stratospheric aerosols should contain equilibrium concentrations of HOBr which equal or exceed those of HBr. Upon uptake of HOBr into aqueous sulfuric acid in the presence of other brominated gases, particularly for 70wt% H2SO4 solution, our measurements demonstrate chemical reaction of HOBr followed by evolution of gaseous products including Br2O and Br2.

scholarly journals Reaction Types of Aqueous Sulfuric Acid Solutions with Nylon.

1959 ◽  
Vol 62 (12) ◽  
pp. 1914-1918
Author(s):  
Shigeru Hayama ◽  
Masanobu Takahashi
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Aqueous Sulfuric Acid ◽  
Sulfuric Acid Solutions

ChemInform Abstract: DECARBONYLATION KINETICS OF FORMIC ACID IN AQUEOUS SULFURIC ACID SOLUTIONS

1976 ◽  
Vol 7 (27) ◽  
pp. no-no
Author(s):  
G. CIUHANDU ◽  
A. DUMITREANU ◽  
Z. SIMON
Keyword(s):  
Sulfuric Acid ◽  
Formic Acid ◽  
Acid Solutions ◽  
Aqueous Sulfuric Acid ◽  
Sulfuric Acid Solutions ◽  
Kinetics Of

Nickel dissolution from nickel matte into the aqueous sulfuric acid solutions

2020 ◽  
Author(s):  
Rudi Subagja ◽  
Iwan Setiawan ◽  
Januar Irawan
Keyword(s):  
Sulfuric Acid ◽  
Acid Solutions ◽  
Nickel Matte ◽  
Aqueous Sulfuric Acid ◽  
Sulfuric Acid Solutions ◽  
Nickel Dissolution
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