Mercuric acetate, and

Strike got the journal article for this recipe as literature citation used in the original Wacker oxidation Strike used for Method 2. In it both mercuric acetate, and to an extent, lead acetate produced ketones as described. Someone-Who-ls-Not-Strike also got a certain ketone. But maybe they were lucky or just plain wrong. Most people on Strike s site say this mercuric acetate thing... 

This following article was sent to Strike by Osmium and Feck (are they the same person ). It involves the direct addition of azide to a terminal alkene (you-know-who) by the in situ production of the reactant mercury (II) azide from mercuric acetate and sodium azide (please don t ask) [80]. 

Treatment of this same 4, 5 -dibromofluorescein intermediate with mercuric acetate and conversion to the disodium salt yields the hydroxymercuric analogue merbromin or mercurochrome [129-16-8] (41). It was once a widely used antiseptic, especially for skin disinfection, and was even adrninistered internally. However, it has been replaced by more effective antibacterial agents. 

Methylation of avermectins B and B2 leads to the corresponding derivatives of the A series (49). A procedure involving the oxidation of the 5-methoxy group with mercuric acetate and NaBH reduction of the 5-keto-intermediate allows the conversion of the A to the B components (50). The 23-hydroxy group of the "2" components, after selective protection of the other secondary hydroxy groups, is converted to a thionocarbonate, which can be elirninated to give the 22,23-double bond of the "1" components alternatively it can be reduced with tributyltin hydride to the 22,23-dihydro derivatives (= ivermectins) (51). 

Mercuration-Thallation. Mercuric acetate and thallium ttifluoroacetate react with benzene to yield phenyHnercuric acetate [62-38-4] or phenylthaHic ttifluoroacetate. The arylthalHum compounds can be converted iato phenols, nitriles, or aryl iodides (31). 

The degradation of the alkaloid to a methylpyridine derivative can be effected through JV-methylgranatic acid (XV) and granatic acid (XVI). The latter, when heated with mercuric acetate and acetic acid at 150° yields 2-methylpyridinecarboxylic acid, which on distillation furnishes 2-methylpyridine. 

To return to a more historical development the mercuric acetate oxidation of substituted piperidines (77) should be discussed next. This study established that the normal order of hydrogen removal from the aW-carbon is tertiary —C—H > secondary —C—H > primary —C—H, an observation mentioned earlier in this section. The effect of substitution variations in the piperidine series can be summarized as follow s l-mcthyl-2,6-dialkyl and 1-methyl-2,2,6-trialkyl piperidines, as model systems, are oxidized to the corresponding enamines the 1,2-dialkyl and l-methyl-2,5-dialkyl piperidines are oxidized preferentially at the tertiary a-carbon the 1-methyl-2,3-dialkyl piperidines gave not only the enamines formed by oxidation at the tertiary a-carbon but also hydroxylated enamines as found for 1-methyl-decahydroquinoline (48) (62) l-methyl-2,2,6,6-tctraalkyl piperidines and piperidine are resistant to oxidation by aqueous mercuric acetate and... 

Extension of these studies to medium rings produced interesting results (73). The mercuric acetate oxidation of 1-methyl-1-azacyclooctane (64), when worked up in the usual manner, gave no distillable material. When an equivalent amount of hydrochloric acid was added to the solution which had been saturated with hydrogen sulfide to precipitate the excess mercuric acetate and filtered, evaporation of the solution to dryness gave a solid which was subsequently identified as 2,4,6-tris(6 -methylaminohexyl)-trithiane trihydrochloride (65). Two plausible routes to the observed... 

To a refluxing solu tion of 100 g of allyl urea and 600 ml of absolute methanol there was added with stirring a suspension of 319 g of mercuric acetate and 600 ml of absolute methanol and 60 ml of glacial acetate acid complete solution resulted. After 6 hours of refluxing, the solution was cooled and clarified by filtration. To this solution there were added 50 g of sodium chloride and 240 ml of water. After a short time a heavy white precipitate settled out. This precipitate, which wes3-chloromercuri-2-methoxy-propylurea, was filtered, washed and dried. 

An extensive investigation has been recently made of the kinetics of mercuration of benzene by mercuric acetate and mercuric perchlorate in acetic acid solvent, and the kinetic details are somewhat complicated439. 

Although mercuration by the two salts above appears at first sight to be fundamentally different, analysis of the above data shows that this is not the case439. Firstly, mercuric perchlorate in acetic acid is partially converted to mercuric acetate and perchloric acid thus, the first step is given by equilibrium (214)... 

Oxidative cyclization of N- [2-indol-3-yl)ethyl] piperidine (146) with 3 molar equivalents of mercuric acetate and EDTA disodium resulted in ( )-l in 85% yield (106). 

Mercuric acetate and thallic acetate have also been used for the oxidative cydiza-tion of vinylallenes (Eq. 13.24) [29]. Exposure of vinylallene 75 to stoichiometric mercuric acetate in acetic acid led to cydopentenone 76 in 75% yield. With thallium acetate as the oxidant, the yield of 76 was 60%. The presumed mechanism of the oxidative cyclization involves a Nazarov cyclization of acetoxymercury intermediate 77. 

Table 5.3 Acidimetric Assays Non-aqueous Titrations with Perchloric Acid using Mercuric Acetate and different Indicators...

At this time there is still a small amount of undissolved mercuric acetate (and mercuric oxide, if used). Longer standing does not improve the yield. 

Mercuric acetate and mercuric trifluoroacetate are the usual reagents.66 The synthetic utility of the mercuration reaction derives from subsequent transformations of the arylmercury compounds. As indicated in Section 7.3.3, arylmercury compounds are only weakly nucleophilic, but the carbon-mercury bond is reactive toward various electrophiles. The nitroso group can be introduced by reaction with nitrosyl chloride67 or nitrosonium tetrafluoroborate68 as the electrophile. Arylmercury compounds are also useful in certain palladium-catalyzed reactions, as discussed in Section 8.2. 

Another method used for nitrate determination on dried and milled herbage employs the nitrate selective electrode. One of the first published methods was that of Paul and Carlson (1968). Other anions, especially chloride, can interfere. These authors removed chloride with silver resin, but Barker ef al. (1971) omitted the resin because it tended to foul the electrode and cause excessive drift. Normally the Cl N03 ratio is so low as not to interfere, but saline precipitation from coastal plots could affect this. The method was further modified to allow storage of extracts for up to 64 h by adding a preservative of phenyl-mercuric acetate and dioxane, both very toxic (Baker and Smith, 1969). This paper mentions the need to change the electrode s membrane, filling solution and liquid ion exchanger every 2 months to minimize chloride interference. It is easy to overlook electrode maintenance between batches of nitrate analyses, and this can lead to errors and sluggish performance. 

The technique of methoxymercuration-demercuration was utilized to determine the position of double bonds in the side chains. Since this method is not successful with the free alkaloids (272), the secondary amino groups must be protected as the A -heptafluorobutyramide. These amides are treated with mercuric acetate and methanol followed by reduction with sodium borohydride to yield the methoxylated compounds (273). The mass spectra of these compounds show a fragment ion (274) at m/z 59 indicating terminal double bonds in every case (Scheme 22) 16,25,410,411). 

Vinyl caproate, caprylate, pelargonate, caprate, myristate, pahnitate, stearate, 10-hendecenoate (undecylenate) and oleate can be prepared in a similar manner, except that in the preparation of the pahnitate and stearate the fatty acids are added to a solution of mercuric acetate and sulfuric acid in vinyl acetate. Vinyl stearate is not redistilled, but the once-distilled product is recrystallized from acetone at 0° (3 ml. of acetone per gram of vinyl stearate). The amount of mercuric acetate employed was 2%, and the amount of 100% sulfuric acid was 0.3-0.4%, of the weight of the stearic acid. Average yields and properties of these vinyl esters are given in the table. 

In 1955, Leonard described a general method for the oxidation of cyclic tertiary amines to give enamines. Quinolizidine was dehydrogenated using mercuric acetate in 5 % aqueous acetic acid by heating on the steam bath for hr to give 92% mercurous acetate and 60% dehydroquinolizidine. 

A chloride-bridged structure has been proposed for the 1 1 adduct, [HgCl2(btaH)]2 (172). Mercury(II) benzotriazolate, Hg(bta)2, has been obtained from mercury(II) perchlorate, benzotriazole, and triethyl-amine in ethanol (172), and from mercuric oxide and benzotriazole (158). Mercuric acetate and chloride react with benzotriazole to form mixed mercury(II) salts, HgX(Ka) (X = MeC02 or Cl) (139). A dimeric structure (Fig. 13) with T-shaped coordination at mercury has been determined by X-ray diffraction methods (203) for the methyl derivative Hg(Me)(bta) (172). Cyclooctane-1,2-dione dihydrazide reacts with HgO... 

Jensen and Rickborn35 have criticised the use of relative reactivities of mercuric salts in reactions such as (15) as a basis for the deduction of reaction mechanism. They point out that, whereas cyclic transition states involving mercuric halides as electrophiles must, of necessity, be four-centred (e.g. (XIV)), the electrophiles mercuric acetate and mercuric nitrate could give rise to six-centred transition states (e.g. (XV)) that might be energetically more favoured than the four-centred. 

An examination of Table 2 reveals that although mercuric acetate and mercuric nitrate have often been used as electrophilic reagents, there are but few instances in which independent evidence as to their mechanism of reaction has been put forward. Positive kinetic salt effects have been observed in the substitution of sec.-butylmercuric acetate by mercuric acetate (with lithium nitrate in solvent ethanol)2, the substitution of di-sec.-butyl mercury by sec.-butylmercuric nitrate (with lithium nitrate in solvent ethanol)11, and the substitution of tetraethyltin by mercuric acetate (with tetra-n-butylammonium perchlorate in methanol)7. In the latter case, it was suggested7 that the observed very large positive kinetic salt effect was possibly due to anion exchange between mercuric acetate and the perchlorate ion. 

Thirty-five grams of mercuric acetate and 25 g. of ammonium thiocyanate are dissolved in 100 ml. of hot glacial acetic acid. A steady stream of hydrogen sulfide is conducted into the hot solution until precipitation is complete. Then the acetic acid is slowly evaporated. (Caution Hydrogen cyanide gas is evolved.) The black precipitate that first appears slowly changes to the red modification as the acid boils away. Until this change is... 

Wysocka23 24 has examined reactions of 13-hydroxylupanine and related compounds. Thus, treatment of 13-hydroxylupanine (12) (axial OH) with mercuric acetate and then borohydride was reported previously to give 13-hydroxy-a-isolupanine (16) (axial OH), but a re-investigation (Scheme 1) shows that the product is an equimolecular mixture of compound (16) and its epimer (15) (equatorial OH) catalytic reduction in the presence of acid instead of the use of borohydride affords a mixture of compound (16) and a-isolupanine (17). The results were rationalized by assuming the formation of dienes (13) and (14) from 13-hydroxylupanine the presence of such species in the dehydrogenation mixture was supported by u.v. and c.d. measurements.24... 

Pyridoxine, HC1 has been assayed by non-aqueous titrations, using 0.1 N perchloric acid in the presence of mercuric acetate and crystal violet indicator (4,6, 10, 87). 

Korinek and Halpern (50) report that solutions of mercuric perchlorate are reduced by hydrogen about ten times more rapidly than is mercuric acetate, and that the product mercurous perchlorate is itself reducible to mercury by a slower, homogeneous reaction with hydrogen. The total rate of reaction of hydrogen is given by the equation... 

Mercuric acetate and a tertiary base in 5% aqueous acetic acid172 yield a mercurated complex, which subsequently forms mercurous acetate and acetic acid. In this manner, quinolizidine (27) and its derivatives,173 l-azabicyelo[4.3.0]nonane, l-azabicyclo[5.3.0]-... 

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