Sodium bromate oxidant

Catalytic Ce(IV) reagent combined with an additional oxidant such as sodium bromate oxidizes hydroquinones, catechols, and their derivatives to quinones in aqueous acetonitrile (e.g., Eq. 7.18).43... 

In MeCN and in combination with a Lewis acid (e.g., AlClj), sodium bromate oxidizes aromatic aldehydes to carboxylic acids. 

Related oxidants that have been exploited to similar ends include l-(rm-butoxy)-13-benzoiodoxol-3(l//)-one 2 and sodium bromate. Oxidation of benzyl ethers by l-(/err-butoxy)-13 benzoiodoxol-3(l//)-one followed by easy basic hydrolysis of the resultant benzoate ester provides a convenient alternative to the usual reductive deprotection. The reaction is carried out in the presence of alkali metal carbonates and the conditions are mild enough to be compatible with other hydroxyl protecting groups such as methoxymethyl, tetrahydropyranyk TBS and acetate. 

Br , r, and CN ions, if present, can be eliminated by adding a high concentration of the sodium bromate oxidizing agent. 

One of the few disadvantages of CAN lies in the quantity of material sometimes required to oxidize alcohols in addition, such processes may not be as systematic or consistent as other methods. However, both ceric ammonium sulfate and CAN have been used as catalysts in the sodium bromate oxidation of secondary alcohols to ketones (Tomioka et al., 1982). 

Recently it was pointed out [6] that potassium and sodium bromate oxidize arenes in good yields in a 3 2 dioxane-water solution by using cerium ammonium nitrate (CAN) as catalyst. Toluene derivatives are oxidized to ca. 1 1 mixture of benzaldehydes and benzoic acids, while ethylbenzenes are converted to acetophenones. According to the proposed mechanistic scheme, water either influences the polarity of the reaction medium or acts as the reagent, reacting with the intermediate benzylic carbonium ion to give a hydroxy derivative, which is oxidized from either Ce or BrOa ions. 

Neutralizing Lotion. The principal active ingredient of cold wave neutralizers is usually an oxidizing agent. The most popular is hydrogen peroxide [7722-84-1J, employed at a concentration of 1—2% it continues to find widespread use. Aqueous solutions of sodium bromate [7789-38-0] at a concentration of 10—20% occasionally are used and are technically preferred over the peroxide formulations because of excellent stabiUty and absence of hair bleaching. Neutralizing powders appear to be on the decline but formulations stiU in use consist of sodium perborate [7632-04-4] combined with hexametaphosphates to improve solubiUty in hard water. 

Oxidation. Oxidation of the -amyl alcohols produces aldehydes, which after continued oxidation can yield acids. This route to aldehydes has httle merit. However, oxidative esterifications with alkah metal hypohaUtes (eg, calcium chlorite, Ca(OCl)2) (49), bromates (eg, sodium bromate, NaBrO )... 

Solutions of 10 5 sodium bromate in seawater were also titrated by using the residual oxidants procedure. The results show that only about 5% of the added bromate appears as residual oxidants. Thus, the apparent residual oxidants remaining after exposure to sunlight could be completely due to bromate. 

When large amounts of copper deposits in boiler mbes cannot be removed with hydrochloric acid due to the relative insolubility of copper, ammonia-based oxidizing compounds have been effective. Used in a single separate stage, the ammonia sodium bromate step includes the introduction into the boiler system of solutions containing ammonium bromate to rapidly oxidize and dissolve the copper. 

It is unstable to heat, neutral or alkaline pH, and can be easily leached out of foods. Thiamin is destroyed by sulfur dioxide (often used as a food preservative), potassium bromate (oxidizing agent used in bread) and by sodium bicarbonate (in chemically leavened breads). 

Oxidative cleavage of alkyl and silyl ethers.4 CAN catalyzes the oxidative ikiivngo of alkyl and silyl ethers to carbonyl compounds with sodium bromate in yield s usually of 75 95% (equation 1). 

Although NaI04 or KI04 are the secondary oxidants used in the vast majority of cases in which alcohols are oxidized with catalytic Ru04, the employment of sodium hypochlorite (NaOCl),31 sodium bromate (NaBrOj )32 or Cl+, electrolytic-ally generated by oxidation of chloride ion,33 have also been reported. 

Cerium (TV) ammonium nitrate (CAN)37 and a cerium (TV) impregnated resin38 are able to catalyze the selective oxidation of secondary alcohols with sodium bromate (NaBrOi). Stoichiometric cerium bromate— CelBrCb h, prepared in situ from barium bromate and cerium (III) sulfate, is also able to perform selective oxidations of secondary alcohols.39... 

Both, sodium bromite (NaBr02)51 and sodium bromate (NaBr03)52 are able to carry out selective oxidations of secondary alcohols in the absence of an added catalyst under properly devised experimental conditions. 

Oxidizer oxygen or other gaseous oxidizer such as chlorine or liquid oxidizer such as bromine or solid oxidizer such as sodium bromate... 

Ammonium cerium(IV) nitrate or cerium(IV) sulfate will catalyze the selective oxidation of secondaiy alcohols with sodium bromate as cooxidant, in this case remote C—C double bonds interfere, but 1,2-diols are not cleaved. It has been found that sodium bromite in aqueous acetic acid will act as a selective oxidant for secondary mary diols without the need for other catalysts (Scheme 21). ... 

A similar rearrangement occurs when a-epoxyketones are refluxed with 30% aqueous sodium hydroxide. Best directions ate those for benzilic acid (90%) from benzoin, sodium bromate, and sodium hydroxide. Oxidation of the benzoin to benzil and rearrangement of benzil to benzilic acid are accomplished in one step. a-Ketoaldehydes and potential a-ketoalde-hydes undergo a similar internal oxidation-reduction reaction in excellent yields, viz.,... 

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