Mercuric Acetate Research Articles

Rhodium(III) catalyzed oxidation of dextrose and maltose by acidic solution of sodium periodate : A kinetic study

The kinetics of rhodium(ΙΙΙ) catalyzed oxidation of dextrose and maltose by sodium periodate in acidic medium has been studied in the temperature range 30-45 °C. The reaction is carried out in the presence of mercuric acetate as a scavenger for iodide ion. The rate shows first order kinetics with respect to the oxidant, sodium periodate and Rh ΙΙΙ for both dextrose and maltose. A suitable mechanism in conformity with the kinetic observations has been proposed and the thermodynamic parameters computed.

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A method for the estimation of plasma arginase is given. It involves preliminary removal of urea with urease, inactivation of urease by phenyl mercuric acetate, followed by incubation of plasma with arginine. The urea produced is estimated on an autoanalyzer. A method for the production of arginase-free urease is given and some factors which influence the results of plasma arginase values are described.

Intramolecular Hydroaminations Mediated by Reductive Mercuration or n‐Butyllithium To Afford 3‐Methyl‐ and 3,4‐Dimethyl‐1,2,3,4‐tetrahydroisoquinolines

AbstractThe synthesis of 3‐methyl‐ and 3,4‐dimethyltetrahydroisoquinolines from aromatic aminoalkenes using intramolecular hydroamination reactions is described. This reaction was achieved by way of a reductive aminomercuration using mercuric acetate followed by sodium borohydride, or by using sub‐stoichiometric amounts of n‐butyllithium. (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2007)

Synthesis of 5‐(6‐Pyridazinone‐3‐yl)‐2‐Glycosylamino‐1,3,4‐Oxadiazoles

AbstractN‐Glycosyl‐2‐(1,4,5,6‐tetrahydropyridazin‐6‐one‐3‐carbonyl)‐hydrazinecarbothioamides 3a‐3g and N‐glycosyl‐2‐(1,6‐dihydropyridazin‐6‐one‐3‐carbonyl)‐hydrazinecarbothioamides 5a‐5g were prepared by the reaction of glycosyl isothiocyanates with the compounds 1,4,5,6‐tetrahydro‐3‐hydrozinecarbonyl‐6‐pyridazinone (1) and 1,6‐dihydro‐3‐hydrozinecarbonyl‐6‐pyridazinone (2). The terminal heterocyclic compounds 1,3,4‐oxadiazole derivatives were obtained from cyclization of compounds (3a‐3g) and (5a‐5g) by mercuric acetate. Their structures were confirmed by IR, 1H NMR, MS and elemental analyses.

Synthesis of Substituted Imidazo[1,5-a]pyridines Starting from N-2-Pyridylmethylamides Using Lawesson’s Reagent and Mercury(II) Acetate

A new method for the synthesis of substituted imidazo[1,5-a]pyridines (2-azaindolizines) starting from carboxylic acid and 2-methylaminopyridine is described. The reaction of the obtained N-2-pyridylmethylamides with Lawesson’s reagent gene­rated the target imidazopyridines, along with the corresponding thioamide intermediates. After a simple filtration on alumina, addition of mercury(II) acetate allowed for total conversion of the thioamides into the imidazopyridines. The reaction conditions, as well as the influence of the substituent in position 3 of the imidazopyridine ring were explored. We also demonstrated that this heterocyclization was racemization free in the presence of a chiral carbon in position α to the heterocycle.

Enhancing the sensitivity of spectrophotometric determination of formic acid with mercury(II) acetate

A precise spectrophotometric method was developed for determination of formic acid. The method surpasses in sensitivity the method based on proper UV absorption of formic acid.

Synthesis and Crystal Structure of {[Hg(RNNNR′)2]2}∞ [R = 4‐C2H5OC(O)C6H4, R′ = 2‐FC6H4] – an Asymmetric 1,3‐Diaryltriazenide Complex of Mercury(II) with 1D Supramolecular Arrangement through Hg‐η2,η2′‐Arene π–Interactions

AbstractThe reaction of 1‐(4‐ethoxycarbonylphenyl)‐3‐(2‐fluorophenyl)triazene with mercury(II) acetate in the presence of potassium methanolate in methanol yields [Hg(RNNNR′)2] [R = 4‐C2H5OC(O)C6H4, R′ = 2‐FC6H4] as light‐yellow crystals. [Hg(RNNNR′)2] complex molecules are associated to [Hg(RNNNR′)2]2 dimeric units through centrosymmetric metal‐η2‐arene π‐interactions. The dimeric units – related to each other by translation – self‐assemble to one‐dimensional chains along to the crystallographic direction [110] through additional centrosymmetric metal‐η2‐arene π‐interactions giving rise to a supramolecular 1D arrangement. The [Hg(RNNNR′)2]2 dimeric units are also characterized by non‐classical intermolecular C‐H···O, and intramolecular C‐H···F hydrogen bonds involving the 4‐EtOC(O) and 2‐F substituents, respectively.

Regiospecific synthesis of 3-(2,6-dihydroxyphenyl)phthalides: application to the synthesis of isopestacin and cryphonectric acid

DBU catalyzed condensation of phthalaldehydic acids and 1,3-diketones has been developed to be a general method for the synthesis of 3-substituted phthalides. This method, in combination with mercuric acetate mediated oxidative aromatization has been utilized for the regiospecific synthesis of isopestacin ( 9) and cryphonectric acid ( 10).

Accessing HgSe x S 1−x Nanoparticles Using the Single-Source Reagent Me3Si–SeS–SiMe3

Mercury-selenosulfide (HgSexS1-x) nanoparticles have been synthesized using the single-source reagent Me3Si–SeS–SiMe3. The reagent distributes Se2− and S2− to the metal core as the reaction between Me3Si–SeS–SiMe3 and mercury acetate occurs via a redox pathway, ultimately giving rise to Se–S bond cleavage. Particles are characterized by EDX, TEM and powder X-ray diffraction analysis in conjunction with UV–Visible absorption spectroscopy.

Human Skin in Organ Culture and Human Skin Cells (Keratinocytes and Fibroblasts) in Monolayer Culture for Assessment of Chemically Induced Skin Damage

Human skin cells (epidermal keratinocytes and dermal fibroblasts) in monolayer culture and human skin in organ culture were exposed to agents that are known to produce irritation (redness, dryness, edema and scaly crusts) when applied topically to skin. Among the agents used were three well accepted contact irritants (i.e., all-trans retinoic acid [RA], sodium lauryl sulfate [SLS] and benzalkonium chloride) as well as the corrosive organic mercury compound, aminophenyl mercuric acetate (APMA), and 5 contact sensitizers (oxazolone, nickel sulfate, eugenol, isoeugenol and ethylene glycol dimethacrylate [EGDM]). As a group, the contact irritants (including the corrosive mercuric compound) were cytotoxic for keratinocytes and fibroblasts and suppressed growth at lower concentrations than the contact sensitizers. The contact irritants also produced histological changes (hyperplasia, incomplete keratinization, loss of the granular layer, acantholysis and necrosis) in organ-cultured skin at dose levels at which the contact sensitizers appeared to be inert. Finally, the profile of secreted molecules from organ-cultured skin was different in the presence of contact irritants versus contact sensitizers. Taken together, these data suggest that the use of organ-cultured skin in conjunction with cells derived from the skin in monolayer culture may provide an initial approach to screening agents for deleterious changes in skin.

Nano-sized HgSe powder: Single-step preparation and characterization

Cycloocteno-1,2,3-selenadiazole, an organometallic selenium precursor reacts with mercury acetate in aq. N, N′-dimethylformamide (DMF) or in ethylene glycol (EG) at a temperature between 120 and 130 °C to afford nano-sized HgSe. The product was characterized by powder X-ray diffraction (XRD), scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), X-ray photoelectron spectroscopy (XPS) and transmission electron microscopy TEM. The electron diffraction analysis showed crystalline nature of nano-particles of HgSe. The calculation made by XRD suggest the particles size to be less than 20 nm which match well with the observations made by TEM. The current method uses 1,2,3-selenadiazole, an organo-selenium compounds thus extending the scope of organo-chalcogen compound in material science.

Cyclization of vinyl ethers derived from amino alcohols

Cyclization of vinyl ethers derived from linear and cyclic α- and β-amino alcohols, catalyzed by mercury(II) acetate gave 2-methyloxazolidines and 2-methylperhydro-1,3-oxazines in 37–94% yield.

Mechanistic studies of oxidation of maltose and lactose by [H 2OBr] + in presence of chloro-complex of Rh(III) as homogeneous catalyst

Kinetic studies in homogeneously Rh(III)-catalyzed oxidation of reducing sugars, i.e. maltose and lactose, by N-bromoacetamide (NBA) in the presence of perchloric acid have been made at 40 °C using mercuric acetate as Br − ion scavenger. The results obtained for the oxidation of both reducing sugars show first-order dependence of the reactions on NBA at its low concentrations, which shifts towards zero-order at its higher concentrations. First-order kinetics in [Rh(III)] and zero-order kinetics in [reducing sugar] were observed. Positive effect of [Cl −] was observed in the oxidation of both maltose and lactose. Order of reaction was found to be one and half (1.5) throughout the variation of [H +] in the oxidation of both maltose and lactose. An increase in the rate of reaction with the decrease in [Hg(OAc) 2] and [NHA] was observed for both the redox systems. The rate of oxidation is unaffected by the change in ionic strength ( μ) of the medium. The main oxidation products of the reactions were identified as formic acid and arabinonic acid in the case of maltose and formic acid, arabinonic acid and lyxonic acid in the case of lactose. A common mechanism for the oxidation of both maltose and lactose, showing the formation of most reactive activated complex, [RhCl 4(H 3O)H 2OBr] +, and an unreactive complex, [RhCl 4(H 2O)(H 2OBrHg)] 2+, has been proposed. Various activation parameters have also been calculated and on the basis of these parameters, a suitable explanation for the reaction mechanism has been given.

Diastereoselective Total Synthesis of (+)‐Morusimic Acid B, an Amino Acid from Morus alba.

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Reaktionsbeteiligung Von Oximfunktionen Bei Der Dehydrierung Von 2-Phenylpiperidin-Derivaten

Mercury(II)-induced dehydrogenation of α-(2-phenylpiperidin-1-yl)-acetophenone oximes 7 gives rise to two different iminium compounds which subsequently react with the neighbouring oxime group. With the mercury(II)-EDTA reagent, (E)-7 forms the cyclic nitrones 9 and 11a, b, whereas (Z)-7 is transformed into oxadiazines 12 and 13a, b. The pairs of diastereomers 11a, b and 13a, b result from the equilibrium involving an iminium oximate species. The introduction of electron donor or acceptor groups into the phenyl substituent in (E)-15 and (E)-16 does not influence significantly the direction of dehydrogenation. With mercury(II) acetate in dilute acetic acid no specifity of the oxime configuration is observed, and the nitrones and oxadiazines are produced together. This may be explained by a reaction with the acetate ion at the iminium oxime stage. NMR experiments in CDCl3 have shown that treatment of nitrone 2 and oxadiazine 3 with CF3COOD causes ring cleavage by prototropy and after longer reaction times generates the same imidazole 23

Micellar effect on the kinetics of oxidation of malic acid by N-bromophthalimide

The effect of cationic surfactant cetyltrimethylammonium bromide (CTAB) and anionic surfactant sodium lauryl sulphate (SDS) on the oxidation of malic acid (MA) by N-bromophthalimide (NBP) has been studied at 40 °C. The reaction exhibits first order dependence on [NBP], fractional and inverse fractional order dependence on [malic acid] and [HClO 4], respectively. The effect of sodium perchlorate (NaClO 4), phthalimide and mercuric acetate has also been done. The rate of reaction increased with an increase in dielectric constant of the medium. CTAB strongly catalyzes the reaction and typical k obs and [CTAB] profile was observed, i.e., with a progressive increase in [CTAB], the reaction rate increased, at higher concentration constancy in k obs was observed, where as SDS slightly retards the reaction. The results are treated quantitatively in terms of Menger and Portnoy and Piszkiewicz models. The various activation parameters in presence of CTAB and SDS have been also evaluated. A suitable mechanism consistent with the experimental finding has been proposed. The rate constants k obs, cooperativity index ( n), binding constants ( K S) with surfactants has been evaluated.

A microcalorimetric study of mercury(II) sorption on KU-2-8 sulfocationite

The thermokinetic characteristics of the sorption of mercury(II) ions on KU-2-8 strongly acidic cationite from mercury acetate solutions was studied using microcalorimetry. The overall heat of sorption and its dependence on the degree of filling of the cationite were determined.

High extraction ability of 1,3-dialkynyl calixarene towards mercury(II) ion

The reaction of 1,3-dipropyn-2-yloxycalix[4]arene with mercury(II) acetate could give mercury-containing alkynyl calixarene polymer. The extraction behavior of 1,3-dipropyn-2-yl-oxycalix[4]arene towards mercury(II) ion was examined. When the mole ratio of Hg 2+/calixarene was 1:1, the extractive percent can reach to 99.1%, and the extraction capacity was up to 431 mg/g. It could also decrease the Hg 2+ concentration from 5 to 0.85 mg/L, which was only 17% of the national standard of effluent and satisfied the national standard of drinking water. The extraction process included chemical reaction.

Electrospray ionization mass spectrometric study of mercury complexes of N-heterocyclic carbenes derived from 1,2,4-triazolium salt precursors

AbstractBy mixing 1,2,4-triazolium salts (precursors of N-heterocyclic carbenes 1–6) with mercury acetate, a number of complexes have been obtained under electrospray ionization condition. Carbenes 1 and 2 contain one carbene center; therefore, they are able to bond only one mercury cation. Carbenes 3–5 contain two carbene centers; therefore, they can bond two mercury cations. Mercury complexes of 1–5 always contain an acetate anion attached to a mercury cation. Carbene 6 also contains two carbene centers; however, its structure allows formation of a complex containing mercury bonded simultaneously to both centers, therefore, the complex that does not contain an acetate anion. The MS/MS spectra taken for complexes of carbenes 1–5 have shown formation of a cation corresponding to N1 substituent (adamantyl or benzyl), and those of complexes of carbenes 3–5 (doubly charged ions) have also shown the respective complementary partner ions. Mercury complex of 2 has yielded some other interesting fragmentation pathways, e.g. a loss of the HHgOOCCH3 molecule. The fragmentation pathway of the mercury complexes of 6 was found to be complicated.

Diastereoselective total synthesis of (+)-morusimic acid B, an amino acid from Morus alba

An efficient, flexible and diastereoselective synthesis of the naturally occurring pyrrolidine amino acid, (+)-morusimic acid B, has been accomplished. Starting from chiral, optically active (+)-(3 S)-hydroxy butyric acid methyl ester the key steps of our synthesis are diastereoselective α-alkylation of its dianion to introduce the main part of the side chain, Curtius rearrangement of the hydrazide derivative to a 2-oxazolidinone followed by N→π-cyclization with mercury(II) acetate to generate the cis-2,5-disubstituted pyrrolidine ring. The remote C-3 stereocentre is established after chain elongation with the dianion of methyl acetoacetate and asymmetric hydrogenation of the resulting β-oxoester with Noyori's Ru(II)-( R)-BINAP catalyst.