Addition Of Mercuric Acetate Research Articles

ChemInform Abstract: Stereospecific Addition of Mercuric Acetate to Strained Norbornene Systems.

AbstractThe compounds (IV) are obtained from the corresponding norbornenes (I) by oxymercuration in methanol (III).

Stereospecific Addition of Mercuric Acetate to Strained Norbornene Systems

Stereospecific Addition of Mercuric Acetate to Strained Norbornene Systems

Potentiometric Non Aqueous Determination of Glaphenine Hydrochloride and in Its Pharmaceutical Formulations

Abstract A direct nonaqueous potentiometric determination of glaphenine hydrochloride and glaphenine authentic compounds and in their pharmaceutical formulations, namely glifanan suppositories, glifanan and adalgur tablets(R) is developed. The method involves the titration with 0.1N aceteous perchloric acid after the addition of mercuric acetate in case of hydrochloride salts, using a combined glass electrode. The results of the method were compared with those of the spectrophotometric1 and the alkalimetric2 procedures. The method can be adopted for quantities ranging between 50 and 500 mg with an accuracy of 102 ± 1.1, 98.8 ± 0.4 and 101.2 ± 0.5 for glifanan suppositories, glifanan tablets and adalgur tablets respectively.

The Influence of the Chlorine Substituent in Some Addition Reactions of 1-Chloronorbornene

The products of electrophilic addition of mercuric acetate, chromyl chloride and nitrosyl chloride to 1-chloronorbornene (4) have been investigated. While the rate of addition is slower than that of norbornene, the magnitude of the directive effect of the chlorine is found to vary significantly from case to case. Thus high regiospecificity is observed in oxymercuration-demercuration, moderate regiospecificity in the addition of nitrosyl chloride, and only minor preference of attachment in chromyl chloride oxidation. High stereospecificity is noted in all cases.

The polarographic determination of isopropenyl esters in aqueous solution

Both mercuration and bromination have been used for the polarographic analysis of isopropenyl esters in aqueous solutions. For mercuration, no disadvantages were found in comparison with the established methods [4,5] for the estimation of vinyl esters in methanol, due to either the lower rate of mercuration [5,22] or the expected lower stability of the depolariser formed in aqueous solution, the hemiacetal mercuric acetate addition product. At concentrations below 10 −2 mol l −1, acetone did not interfere [38] with the determinations.

Mechanistic aspects in syntheses and reactions of dipivaloylmethylmercury compounds

Several mechanistic aspects in the syntheses and reactions of dipivaloylmethylmercury compounds were studied. It was found that mercuric acetate adds to dipivaloylmethane (HDPM) in 75% aqueous ethanol to provide an 80% yield of dipivaloylmethylmercuric acetate (DPMHgOAc). The addition of mercuric acetate to HDPM is postulated to occur via electrophilic attack of +HgOAc on the double bond of the enol tautomer of HDPM to give, after loss of a proton, a C-bonded Hg compound, DPMHgOAc, which can symmetrize in 95% ethanol to afford, after the addition of water, bis(dipivaloylmethyl)mercury (DPM 2Hg). DPMHgOAc undergoes an oxymercuration reaction with styrene in 80% aqueous methanol to yield a product from addition of +HgOAc and −OCH 3 to styrene. Photolysis of DPMHgOAc in chloroform with a Pyrex filter gave a quantitative yield of HDPM and mercurous acetate. Homolytic cleavage of the carbon—mercury bond followed by abstraction of hydrogen from CHCl 3 by DPM and radical dimerization of HgOAc provides a rationalization for the observed products. Electrophilic cleavage of (DPM) 2Hg with HgCl 2 and Hg(OAc) 2 according to the equation: (DPM) 2Hg + HgX 2 ⇌ 2 DPMHgX give equilibrium constants ( K) which lie toward DPMHgX. Thus when X = Cl, K = 620 ± 60, and when X = OAc, K = 1.3 x 10 5 ± 1 x 10 4. Electrophilic cleavage of (DPM) 2 Hg with glacial acetic acid gave DPMHgOAc and HDPM in quantitative yield. A discussion of the importance of σ—π conjugation in properties of dipivaloylmethylmercury compounds will also be presented.

Kinetics and mechanism of oxidation of secondary alcohols by potassium bromate

The oxidation by Br(V) of propan-2-ol follows the rate law (−d[Br(V)]/dt) = k 4 [alcohol][Br(V)][H +] 2. The initial reaction is complicated by the presence of the product bromide ion. The reaction is composed of two second order reactions—the first, a comparatively slow one and the second stage, a faster reaction which is mainly bromine oxidation. The pure bromate oxidation can be followed by the initial addition of mercuric acetate which prevents the accumulation of bromine in the system under these conditions. The reaction rate does not depend on the nature and structure of the alcohol. A mechanism involving a slow rate-determining formation of an alkyl-bromate ester followed by a fast decomposition to the products is in accord with the observed results.

Reaction of mono- and disilacyclobutanes with mercury (II) salts

A study was made of the reaction of mercury salts with various mono- and disilacyclobutane derivatives, which proceeds with an opening of the carbosilicon heterocycle at the Si-C bond. The obtained data testify in support of the electrophilic nature of the addition of mercuric acetate to silacyclobutanes.

Separation by gel chromatography of naturally occurring phosphatidylcholine mixtures according to number of ethylenic linkages

This paper describes a procedure for the separation of lecithins according to the number of ethylenic bonds in their fatty acid residues. The procedure uses a column of alkylated dextran (Sephadex LH-20) eluted with an organic solvent system, the unsaturated lipids being separated as their mercuric acetate addition compounds. The system is capable of resolving at least four species of lecithin, and the intact lecithin molecules can be recovered for further study. The chromatographic system has been tested with lecithin derived from dog lung, rat liver, and hen's egg.

Zur Katalyse der Umvinylierungen

AbstractIt is shown that the vinyl interchange reaction between vinyl acetate and carboxylic acids proceeds by an acid catalysed addition of mercuric acetate to the vinyl double bond; the corresponding organomercuric intermediate has been isolated and identified.

Methoxymercuration of acrylonitrile

The addition of mercuric acetate to acrylonitrile in methanol has been kinetically studied at 45°. The reaction is greatly accelerated by perchloric acid and appreciably retarded by acetic acid, whereas sodium acetate and nitrogen bases have very little effect on the reaction rate. The mechanism appears to be different from that operating in the reaction with α,β-unsaturated carbonyl compounds. The addition presumably occurs through a non-ionic mechanism involving the prior formation of methoxy-mercuric acetate as the reactive species.

Isolation of pure linolenate as its mercuric acetate adduct

AbstractAfter addition of mercuric acetate to the unsaturated methyl esters obtained from the methanolysis of linseed oil, linolenate of 99% minimum purity was isolated by means of a liquid‐liquid continuous extraction technique and subsequent decomposition of the mercurial adduet. The methyl linolenate‐mercuric acetate addition compound was extracted with 10% methanol in water from an ether solution of the reaction mixture. Infrared analysis of the regenerated methyl linolenate showed the complete absence oftrans‐linkages. The yield, at least 60% of the linolenic acid present in linseed oil, was considerably higher than that obtained by bromination‐debromination procedures.The solubility in aqueous solutions of fatty acid derivatives having 3 or more acetoxymer‐euri‐groups/molecule provides an approach to the fractionation of highly unsaturated oils. For example, a fraction having an iodine value of 395 was isolated readily from the methyl esters of pilchard oil by this technique.

Use of mercuric acetate addition to prepare unsaturated fatty ester concentrates

AbstractMereuric acetate in methanol was reacted with unsaturated fatty acid esters in mixtures prepared from linseed, safflower and menhaden oils and pig liver and beef adrenal lipids. Methanol solutions retained predominantly the adducts of the more highly unsaturated esters when extracted with either n‐pentane or commercial pentane (Skellysolve F). The free esters were recoverable from the adducts.Linoleate of 95% purity and linolenate of 90% purity were obtained directly from natural oils by this procedure. Concentrates of more highly unsaturated acids were obtained similarly.

Circular Paper Chromatography as a Simple Analytical Method for Fatty Acids and Glycerides

A simple and rapid method for the separation and identification of fatty acids and glycerides has been developed by using circular paper chromatography. Petroleum hydrocarbon, dodecylbenzene, and tetralin were used as the stationary solvents. As the developing solvents, 90% acetic acid and methanol-acetic acid, both saturated with a stationary solvent, were suitable for the separations of fatty acids and of glycerides respectively. The fatty acids were detected on paper by successive treatment with 0.5% lead acetate, water, and ammonium sulfide solution. The selective detection of unsaturated acids by spraying with a 2% solution of iodine in ethanol was also applied. The separation of various “critical partners” of fatty acids was achieved by the method of double development, involving the first low-temperature development with petroleum ether under dry ice and the second reversed-phase development with the usual solvent systems at room temperature. The unsaturated glycerides were chromatographed as their mercuric acetate addition compounds, and were detected by spraying with a 0.2% solution of diphenylcarbazone in ethanol or by soaking in a Sudan black solution. The clear-cut separations of fatty acids and glycerides into their homologs can be attained by these circular chromatographic techniques, since the separation of unsaturated triglycerides mainly depends on their unsaturation and that of mono-, di-, and triglycerides mainly depends on the number of their free hydroxyl groups. This method was successfully applied to the analysis of various fats, fatty acids, and their products, and was confirmed to be of great value as a simple, rapid, and practical method for their analysis.

Paper chromatography of egg lecithins

Egg lecithins have been fractionated as their mercuric acetate addition compounds by reversed-phase paper chromatography. The component fatty acids of the original and chromatographically fractionated lecithins and the fatty acids on the α′- and β-ester positions have been clarified by use of paper chromatographic and spectrophotometric methods. On the basis of these analytical results the distribution of fatty acids in egg lecithins is discussed.

Separation and Identification of Fatty Acids

For the characterization of fatty acids, 2, 4-dinitrophenylhydrazones of p-bromophenacyl esters of even-numbered saturated fatty acids from C2 to C20 and several unsaturated fatty acids from monoethenoid to triethenoid were prepared. The derivatives of linoleic and linolenic acids as well as those of the other unsaturated and saturated acids, were successfully obtained in crystalline forms which showed sharp and high melting points, 72° and 69°, respectively. It was found that the derivatives of unsaturated acids were valuable for characterizing the parent acids, while those of saturated acids were unsuitable for this purpose owing to the similarity of their melting points. By reversed-phase paper chromatography, the simultaneous separations of all saturated and unsaturated fatty acids were successfully carried out on the same paper with the aid of p-bromophenacyl ester 2, 4-dinitrophenylhydrazones and their mercuric acetate addition compounds. When petroleum hydrocarbon (b. p. 140–170°) was used as the stationary solvent and methanol—acetic acid—petroleum hydrocarbon as the moving solvent, even saturated acids from C4 to C22, even monoethenoid acids from C10 to C22, and C18 series from stearic to linolenic were well separated, respectively. Similar separations were also attained on paper impregnated with decalin and olive oil. From the results of several applications, this method has been found to be effective for the analysis of the component acids in natural fats.

Addition reactions of perfluoroolefins communication 5. Conjugated addition of halogens

1. It was shown that 3, 3, 3-trifluoropropene, trifluoroethylene, and 1,1-diflnoroethylene readily undergo addition of bromine in glacial acetic acid. 2. For the first time, fluoroolefins were caused to undergo conjugated addition. By the action of bromine on some fluoroolefins in glacial acetic acid, some acetic esters of β -bromo α,α -difluoro alcohols were prepared. 3. It was shown that compounds of this new type have the character of mixed acid anhydrides. 4. By conjugated addition of bromine in water, the bromohydrin of 3,3,3-trifluoropropene was obtained, and this was converted into 2,3-epoxy- 1,1,1-trifluoropropane. 5. By conjugated addition of bromine to trifluoroethylene in water, bromofluoroacetic acid was obtained. 6. The addition of mercuric acetate to 1,1-difluoroethylene was effected in acetic acid and in alcohol, the products being the unstable 2-acetoxy-2,2-difluoroethylmercury and 2-ethoxy-2,2-difluoroethylmercury acetates, which are readily transformed into a (halomercuri)acetic acid and its esters.

Addition of mercury salts to vinyl ethers Preparation of mercurated acylals

1. By the addition of mercuric acetate to vinyl ether, mercurated acylals of the following general formula were prepared: 2. By an investigation of the chemical behavior of the mercurated acylals it was established that they have dual reactivity. 3. Bromo acylals of the following formula were synthesized: R=C2H21−C3H2, C4H3.

Separation and Identification of the Fatty Acids

By reversed-phase paper chromatography, the simultaneous separations of all saturated and unsaturated fatty acids were successfully carried out on the same paper with the aid of p-bromophenacyl ester 2, 4-dinitrophenylhydrazones and their mercuric acetate addition compounds. When petroleum hydrocarbon (b. p. 140-170°) was used as the stationary solvent and methanol-acetic acid-petroleum hydrocarbon as the moving solvent, even saturated acids from C4 to C22, even monoethenoid acids from C10 to C22, and C18 series from stearic to linolenic were well separated, respectively. Similar separations were also attained on paper impregnated with decalin and olive oil. From the results of several applications, this method has been found to be effective for the analysis of the component acids in natural fats.

Paper chromatography of unsaturated fatty acid esters as their mercuric acetate addition compounds

SummaryA method is described by which unsaturated fatty acid esters can be separated and identified by reversed‐phase paper chromatography. The procedure is based upon the formation of the mercuric acetate addition compounds of the esters and the detection of the compounds on the chromatograms, using the sensitive color reaction with diphenylcarbazone. The application of this technique to the analysis of the component unsaturated acids of natural fats has been examined, and tetradecenoic acid in olive oil and hexadecenoic acid in linseed oil both formerly unidentified have been detected as the minor component acids by means of the method. The preliminary investigation on the absorption spectra of diphenylcarbazone complexes derived from the addition compounds has been made to bring the method into quantitative use.