Potassium peroxymonosulfate oxidation with

Bromide ndIodide. The spectrophotometric determination of trace bromide concentration is based on the bromide catalysis of iodine oxidation to iodate by permanganate in acidic solution. Iodide can also be measured spectrophotometricaHy by selective oxidation to iodine by potassium peroxymonosulfate (KHSO ). The iodine reacts with colorless leucocrystal violet to produce the highly colored leucocrystal violet dye. Greater than 200 mg/L of chloride interferes with the color development. Trace concentrations of iodide are determined by its abiUty to cataly2e ceric ion reduction by arsenous acid. The reduction reaction is stopped at a specific time by the addition of ferrous ammonium sulfate. The ferrous ion is oxidi2ed to ferric ion, which then reacts with thiocyanate to produce a deep red complex. 

Oxidation of Chlorides. Hypochlorite can also be formed by the in situ oxidation of chloride ions by potassium peroxymonosulfate [25482-78-4] (36). Ketones like acetone cataly2e the reaction (37). The triple salt of potassium peroxymonosulfate is a stable powder that has been combiaed with chloride salts and sold as toilet bowl cleaners. Bromides can be used ia place of chlorides to form hypobromites, and such combiaations are used to disiafect spas and hot tubs. 

Oxone is a registered trademark of DuPont with potassium peroxymonosulfate KHSOs (potassium monopersulfate) as oxidizing ingredient of a triple salt with the formula... 

All forms of iodine including the elemental iodine, hypoiodous acid (HOI), hypoiodite anion (OI ), free iodide anion (I-), and triiodide anion (I3 ) in water also may be measured by the Leuco crystal violet method. The sample is treated with potassium peroxymonosulfate to oxidize all iodide species in the sample. It then is treated with leukocrystal violet reagent for color development. Interference from free chlorine may be eliminated by addition of an ammonium salt. 

Both isomeric forms of (+)- and (—)-(camphorylsulfonyl)oxaziridines are available by oxidation of the corresponding sulfonimines with buffered potassium peroxymonosulfate (oxone). Since oxidation can only take place from the endo-fa.ce of the C=N double bond due to steric blocking of the exo-face, a single oxaziridine isomer is obtained. The enantiomerically pure sulfonimines can be prepared in three steps in better than 80% yield from inexpensive (+)- and (—)-camphor-10-sulfonic acids. Alternatively they are commercially available200. 

In acidic oxidations of primary alcohols, esterification of the alcohol by the acid produced by its oxidation sometimes takes place. Thus the oxidation of ethanol with potassium peroxymonosulfate (Oxone) in the presence of concentrated sulfuric acid at 70 °C gives a quantitative yield of ethyl acetate [205]. 

More energetic oxidation of thiols leads to sulfonic acids, Thiophenol dissolved in a solution of potassium hydroxide in dimethylformamide is oxidized by oxygen at 23.5 °C over a 22-h period to benzenesulfonic acid in 91% yield [53], Lauryl mercaptan gives dodecanesulfonic acid in 100% isolated yield upon treatment with potassium peroxymonosulfate, 2KHS05 KHS04 K2S04, at room temperature for 30 min [205]. 

An efficient, high-yield synthesis of A-alkyl and A-aryl oxaziridine by oxidation of aldimines with buffered Oxone (potassium peroxymonosulfate) has been introduced by Hajipour and Pyne (Equation (47)) <92JCR(S)388>. Oxidation of the aldimine is accomplished in aqueous NaHC03/ acetonitrile or acetone affording the oxaziridine within 15-30 minutes in excellent yield (95-98%). The active oxidizing species in acetone and acetonitrile are thought to be dimethyldioxirane and peroxyimidic acid [MeC(OOH)=NH), respectively. 

Recent work with main group catalysts has concentrated on the use of Oxone (potassium peroxymonosulfate) as co-oxidant with organic ketone derivatives. Shing et al. have described an arabinose ketone catalyst containing a tuneable butanediacetal functionality (Fig. 1.2e) which can be used for asymmetric epoxidation with up to 90% ee [198]. The group of Shi reports on a range of ketones bearing... 

Halogens can also be generated in situ by the action of an oxidizing agent on a sodium halide.226 In this example (3.16), the oxidizing agent is potassium peroxymonosulfate (Oxone). The reactions were run in water diluted with acetone, ethyl acetate or carbon tetrachloride. Bromine can... 

Schemes have been devised to substitute less toxic metals for more toxic ones. Potassium ferrate on K10 mont-morillonite clay has been used to replace potassium chromate and potassium permanganate in the oxidation of alcohols to aldehydes and ketones in 54-100% yields.153 The potassium ferrate is made by the action of sodium hypochlorite on iron(III) nitrate or by treatment of iron(III) sulfate with potassium peroxymonosulfate.154 After the oxidation, any excess oxidizing agent, and its reduced form, are easy to recover by filtration or centrifugation. In another case, manganese-containing reagents have been substituted for more toxic ones containing chromium and selenium (4.21).155 Selenium dioxide was used formerly in the first step and pyridinium chlorochromate in the second.

Dioxiranes are good selective oxidants. Some /3-diketones have been oxidized to alcohols (4.56) in 95% or higher yield.269 The dioxiranes are made and used in solution. The nickel catalyst speeds up reaction 4.56. Hydrocarbons can be functionalized (4.57) in up to 92% yield in this way.270 A dioxirane phase-transfer catalyst, produced in situ with potassium peroxymonosulfate, has been used epoxidize an olefin to an epoxide (4.58) in up to 92% yield.271... 

Potassium peroxymonosulfate has been used in the Nef reaction to convert 1-nitrohexane to caproic acid in 98% yield.275 Replacement of the potassium ion by tetrabuty-lammonium ion allows the oxidant to be used in acetonitrile and methylene chloride. (Less toxic solvents would be desirable.) When this reagent was used with a manganese catalyst, 1-octene was epoxidized in more than 99% yield.276 It also converted ethylbenzene to acetophenone with more than 99% selectivity. 

The reaction of thieno[2,3-Zi]thiophene (142) with Bu"Li affords a lithium intermediate, whose treatment with elemental sulfur and bromopentane produces sulfide 169. Regioselective iV-sulfonation of the latter was successfully carried out by successive reactions with Bu"Li, SO2 and hydroxylamino-O-sulfonic acid. Selective oxidation of sulfide 170 with potassium peroxymonosulfate afforded sulfone 171 (99JHC249). 

Dioxiranes for alkene epoxidation may be prepared in situ from a catalytic amount of a ketone and Oxone (potassium peroxymonosulfate triple salt). )V,)V-Dimethyl-and A, A -dibenzylalloxans (20a) and (20b) (Figure 3) have been prepared and used as novel dioxirane catalysts for the epoxidation of a range of di- and tri-substituted alkenes in good to excellent yield. H2O2 (rather than the usual Oxone) has been successfully used as primary oxidant in asymmetric epoxidations with Shi s fructose-derived ketone (21) in acetonitrile. The ketone is converted into the dioxirane, which is responsible for epoxidation and the active oxidant responsible for dioxirane formation is proposed to be peroxyimidic acid formed by combination of H2O2 with acetonitrile. ... 

Metallo-N4 complexes are easily adsorbed on different organic and inorganic matrices, which promoted the use of phthalocyanines or porphyrins adsorbed on, e.g., humic acids as heterogeneous catalysts in the chemical oxidation of phenols by potassium peroxymonosulfate, KHSO5 [34]. Fe(III)-TPPS, Mn(III)-TPyP, Fe(III)-TSPc and Cu(II)-TSPc were adsorbed on these matrices, the complexes with Mn (III) and Fe(ni) being the more efficient ones for phenols degradation. The higher efficiency in the presence of humic acids was attributed to the hydrophobic character of the latter, which contributed to the interaction of the catalyst with the phenols. 

The purification of the water has been previously described (10). With the exception of the arsenious oxide (from Carlo Erba, Italy), the chemicals used were Merck analytical products. The peroxymonosul-fate samples were obtained from hydrolysis of potassium peroxydisulfate solutions a 10"2M K2S208 solution in 1M sulfuric acid was heated at 60 °C. for 75 minutes and let cool overnight inside the thermostated bath (an ultrathermostat Colora was used). Under these conditions, the peroxydisulfate remaining in the solution, as well as the hydrogen peroxide formed in the simultaneous hydrolysis of the Caro s acid, are small when compared with the resulting peroxymonosulfate concentration. 

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