ELECTROPHILIC CATALYSIS IN SOLVOLYTIC REACTIONS: VII. SOLVENT EFFECT

1965 ◽  
Vol 43 (6) ◽  
pp. 1770-1777 ◽  
Author(s):  
R. Anantaraman ◽  
K. Saramma
Keyword(s):  
Solvent Effect ◽  
Mercuric Chloride ◽  
Aqueous Ethanol ◽  
Chloride Ions ◽  
Aqueous Acetone ◽  
Normal Reaction ◽  
Suggested Explanation

The rates of mercuric chloride catalyzed solvolysis of some alkyl chlorides in aqueous acetone and ethanol solvents have been compared. It is found that the increase in rate on changing from the acetone to the ethanol solvent is less in the catalyzed than in the normal reaction. On the basis that the electrophilic activity of the catalyst is less in aqueous ethanol than in aqueous acetone an explanation for the anomaly has been suggested. The effect, on the rates of solvolysis, of added chloride ions is in accord with the suggested explanation.

ELECTROPHILIC CATALYSIS IN SOLVOLYTIC REACTIONS: IX. INDUCTOMERIC EFFECT

1966 ◽  
Vol 44 (20) ◽  
pp. 2415-2419 ◽  
Author(s):  
R. Anantaraman ◽  
M. R. Nair
Keyword(s):  
Mercuric Chloride ◽  
Aqueous Ethanol ◽  
Chloride Ions ◽  
Aqueous Acetone ◽  
Rate Of Hydrolysis ◽  
Presence And Absence ◽  
Catalyzed Reactions

The rates of solvolysis of 1-(p-alkylphenyl)ethyl chlorides (Alk = Me, Et, i-Pr, and t-Bu) in the presence and absence of mercuric chloride have been measured in aqueous acetone and ethanol solvents. In all cases, the Baker–Nathan order is followed. For all normal reactions and for the catalyzed reactions in 90% aqueous acetone and 90% aqueous ethanol there is an increase in the heats and entropies of activation as the series is ascended, while for the catalyzed reaction in 75% and 80% aqueous acetone, there is a decrease. It is suggested that in the more aqueous acetone solvents the catalyst calls into play an inductomeric effect. The effect of added chloride ions on the rate of hydrolysis has been studied and the results are discussed.

Pigments of marine animals. XIV. Polyketide sulfates from the crinoid Comatula pectinata

1981 ◽  
Vol 34 (11) ◽  
pp. 2385 ◽  
Author(s):  
JA Rideout ◽  
MD Sutherland
Keyword(s):  
Sodium Bicarbonate ◽  
Sodium Salt ◽  
Aqueous Ethanol ◽  
Aqueous Acetone ◽  
Chromatographic Mobility ◽  
Sulfate Ester ◽  
Marine Animals ◽  
Free Phenol ◽  
Tertiary Alcohols ◽  
Trimethyl Ether

The polyhydroxyanthraquinones known from the crinoid Comatula pectinata are shown to be present largely as (fish repellent) sulfate monoesters. The sodium salt of the 3-O-sulfate of 4-butyryl-1,3-dihydroxy-6,8-dimethoxy-9,10-anthraquinone was isolated by its chromatographic mobility on alumina in aqueous acetone or on sodium bicarbonate in aqueous ethanol. The sulfate hydrolyses readily to the free phenol and is methylated (Me2SO4/K2CO3 in refluxing acetone) to 4-butyryl-1,3,6,8-tetramethoxyanthraquinone. Methylated in the presence of tertiary alcohols however, the sulfate ester resists cleavage, yielding the 1,6,8-trimethyl ether, hydrolysable to 4-butyryl-3-hydroxy-1,6,8-trimethoxyanthraquinone.

CARBOHYDRATES CONTAINING NITROGEN IN A FIVE-MEMBERED RING AND AN ATTEMPTED SYNTHESIS OF A CARBOHYDRATE WITH NITROGEN IN A SEVEN-MEMBERED RING

1965 ◽  
Vol 43 (8) ◽  
pp. 2345-2356 ◽  
Author(s):  
W. A. Szarek ◽  
J. K. N. Jones
Keyword(s):  
Mercuric Chloride ◽  
Acid Treatment ◽  
Membered Ring ◽  
Aqueous Acetone ◽  
Lead Tetraacetate ◽  
Alkaline Degradation ◽  
Cadmium Carbonate

Lead tetraacetate oxidation of 6-acetamido-6-deoxy-D-galactose (IX) yielded a syrup which was converted to a compound formulated as 4-acetamido-4-deoxy-1,2-O-isopropylidene-D-threofuranose (XII). The same syrup was obtained by alkaline degradation of the product of oxidation of 5-acetamido-5-deoxy-D-xylose diethyl dithioacetal (XVII) with peroxypropionic acid. Treatment of compound XII with p-toluenesulfonyl chloride yielded crystalline 4-acetamido-4-deoxy-1,2-O-isopropylidene-3-O-p-tolylsufonyl-D-threofuranose (XIII).Demercaptalation of 6-acetamido-2,3,4,5-tetra-O-acetyl-6-deoxy-D-galactose diethyl dithioacetal (XX) with mercuric chloride and cadmium carbonate in aqueous acetone did not yield a nitrogen-containing septanose ring but an acyclic derivative.

A Direct Photometric Method for Chloride in Biological Fluids, Employing Mercuric Thiocyanate and Perchloric Acid

1966 ◽  
Vol 12 (1) ◽  
pp. 1-17 ◽  
Author(s):  
Robert Houston Hamilton
Keyword(s):  
Perchloric Acid ◽  
Mercuric Chloride ◽  
Biological Fluids ◽  
Chloride Concentration ◽  
Chloride Ions ◽  
Photometric Method ◽  
Ferric Ions ◽  
Other Substances ◽  
Mercuric Ions ◽  
Total Absorbance

Abstract The reagent described is 5.5 M in perchloric acid and 3.3 M in urea. It contains ferric ions, mercuric thiocyanate, mercuric ions (from mercuric perchlorate), and mercuric chloride. Serum dissolves directly in this reagent to yield a clear, reddish solution. When chloride ions are added, they combine first with the free mercuric ions, and then with some of the mercuric ions from the mercuric thiocyanate. Liberated thiocyanate combines with ferric ions to yield red ferric thiocyanate. The color is much more intense in the presence of strong perchloric acid than in other aqueous acid mixtures, Its intensity can be regulated at will by changing the concentration of the ferric iron. The presence of mercuric chloride in the reagent improves linearity between absorbance and chloride concentration. After the total absorbance is determined, compensation for absorbance by other substances is secured by adding mercuric ions to the photometer tube to reverse the color-producing reaction of chloride, reading the residual absorbance, and subtracting it from the total absorbance, to give a net absorbance produced by chloride alone.

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