Acetate, electrolytic oxidation

The following alternative procedure may be used to prepare a solution of disodium hydroxylaminedisulfonate. Sodium nitrite (15 g., 0.217 mole) and 41.6 g. (0.40 mole) of sodium bisulfite are added to 250 g. of ice. With stirring, 22.5 ml. (0.40 mole) of acetic acid is added all at once and the mixture is stirred for 90 minutes in an ice hath. At the end of the stirring period the reaction solution is pH 5 and a potassium iodide-starch test is negative. A solution of 50 g. (0.47 mole) of sodium carbonate in water (total volume 250 ml.) is added. This buffered solution of disodium hydroxylaminedisulfonate may be used for electrolytic oxidation. 

Electrochemical oxidation of pentafluoroaniline (1) at a platinum anode at a potential of +1.5 to 1.6 V (vs SCE) using an acctonc/water/potassium acetate electrolyte leads to decafluoro-diphenyldiazene (3) and octafluorophenazine (2) in 18% and 6% yield, respectively. The phenazine heterocycle is formed by a sequence of oxidation/substitution steps in which nitrogen radical intermediates substitute fluorine atoms. The low yield in this reaction is due to a laborious workup.203 204... 

Bromine or electrolytic oxidation of furan in alcoholic solution gives the corresponding 2,5-dialkoxy-2,5-dihydrofuran 159 (R = Alk). Lead tetraacetate in acetic acid oxidation yields 2,5-diacetoxy-2,5-dihydrofuran 159 (R = Ac). 

Non-Reversible Processes. —Reactions of the non-reversible type, i.e., with systems which do not give reversible equilibrium potentials, occur most frequently with un-ionized organic compounds the cathodic reduction of nitrobenzene to aniline and the anodic oxidation of alcohol to acetic acid are instances of this type of process. A number of inorganic reactions, such as the electrolytic reduction of nitric acid and nitrates to hydroxylamine and ammonia, and the anodic oxidation of chromic ions to chromate, are also probably irreversible in character. Although the problems of electrolytic oxidation and reduction have been the subject of much experimental investigation, the exact mechanisms of the reactions involved are still in dispute. For example, the electrolytic reduction of the compound RO to R may be represented by... 

If neutral salts are added to the electrolyte, especially if this consists of acetic acid only, with no acetate, the extent of the Kolbe reaction is diminished under these conditions also, methyl alcohol is formed by the so-called Hofer-Moest reaction (1902). When the conditions are such that the acetate is oxidized to ethane the anode potential is about 2.2... 

Many of the classic partitioning processes rely on the formation of Am" to facilitate separation from trivalent lanthanides or heavier trivalent actinides. Americium(VI) can be prepared in basic aqueous solutions from Am using powerful oxidants, such as peroxydisulfate, and from Am using weaker oxidants, such as Ce. It can be precipitated from solution as a carbonate by electrolytic or ozone oxidation of concentrated carbonate solutions of Am or Am, or solubilized by dissolution of sodium americyl(VI) acetate. These oxidations and the resulting coordination compounds have been used for relatively large scale processing. For examples, Stephanou et found that Cm could be separated from Am by oxidizing the latter to Am with... 

Prepd by electrolytic oxidation of Co(C2H30,)2.4H20in glacial acetic acid contg 2% (v/v) water Sharp, White, J. 

Fuming nitric acid in the presence of acetic anhydride oxidizes iodine, producing the compound I(OCOCH3)3. On oxidation of iodine with concentrated nitric acid in the presence of acetic anhydride and phosphoric acid, the compound IP04 is obtained. No direct structural information is available for these compounds, but they are probably best regarded as covalent. Nevertheless, electrolytic dissociation can occur and when a saturated solution of I(OCOCH3)3 in acetic anhydride is electrolyzed the quantity of silver iodide formed at a silvered platinum gauze cathode is in... 

In 1859, Friedel electrolytically oxidized acetone and found a mixture of formic, acetic, and carbonic acids with evolution of carbon dioxide and oxygen at the anode in an acetone-sulfuric acid mixture. Further studies on ketones were not reported until 1931, when a similar study was carried out resulting in the formation of methane, ethane, and unsaturated hydrocarbons, in addition to carbon dioxide and oxygen at platinum anodes. The first anodic oxidation of benzene was reported in 1880, with the observation that the electrolytic oxidation of benzene in an ethanolic-sulfuric acid medium yielded unidentifiable substances. A few years later Gotterman and Friedrichs reported that hydrocarbons were obtained from the anodic oxidation of benzene in alcoholic-sulfuric acid solution at platinum anodes. 

Fructose or other carbohydrates containing hexoses provide a cheap source for the two substituted furfurals 345,346 (Reaction scheme 237) [711]. Catalytic reduction of the acetate 348 cleaves at the heterobenzylic position to give 5-methylfurfural 347. Electrolytic oxidation affords a polyreactive intermediate 349 for future purposes. Weakly acidic thermal treatment causes rearrangement to a norpyrethrolone 350. 

Hara [237] prepared perchlorate, sulfate, and acetate solutions containing Am02 free of Am by first extracting AmO from buffered 1m acetate (pH 3) solutions of Am(iii) and Am(v) into 0.1 M thenoyltrifiuoroacetone in isobutanol and back-extracting the Am(v) into an aqueous phase. More exotic methods for obtaining the AmOj ion in aqueous solution include dissolution of solid U3 Am04 in dilute perchloric acid or the electrolytic oxidation of Am(iii) in 2 M LilOj/O. M HIOj (pH 1.47) solution [3]. 

The so-called metaplumbates M Pb03.3H20 are made by fusing lead(IV) oxide with an excess of potassium hydroxide. 83. These compounds are actually the alkali metal salts of the hexahydroxylead(IV) anion Pb(OH) . The salts contain discrete Pb(OH) " ions analogous to the corresponding Sn(OH) of tin(IV) 4> 5. Na2Pb(OH)6 has also been made by the electrolytic oxidation of alkali hydroxide solutions of Pb(II), and also by the controlled alkali hydrolysis of lead(IV) acetate. ... 

Selectivity of propylene oxide from propylene has been reported as high as 97% (222). Use of a gas cathode where oxygen is the gas, reduces required voltage and eliminates the formation of hydrogen (223). Addition of carbonate and bicarbonate salts to the electrolyte enhances ceU performance and product selectivity (224). Reference 225 shows that use of alternating current results in reduced current efficiencies, especiaHy as the frequency is increased. Electrochemical epoxidation of propylene is also accompHshed by using anolyte-containing silver—pyridine complexes (226) or thallium acetate complexes (227,228). 

Aromatic ethers and furans undergo alkoxylation by addition upon electrolysis in an alcohol containing a suitable electrolyte.Other compounds such as aromatic hydrocarbons, alkenes, A -alkyl amides, and ethers lead to alkoxylated products by substitution. Two mechanisms for these electrochemical alkoxylations are currently discussed. The first one consists of direct oxidation of the substrate to give the radical cation which reacts with the alcohol, followed by reoxidation of the intermediate radical and either alcoholysis or elimination of a proton to the final product. In the second mechanism the primary step is the oxidation of the alcoholate to give an alkoxyl radical which then reacts with the substrate, the consequent steps then being the same as above. The formation of quinone acetals in particular seems to proceed via the second mechanism. ... 

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