Reagent oxidizing

Dissolve 5g of purified K2S2O8 and 3g of H3BO3 in 100 mL of the 0.375 mol/L NaOH (see Section 10.2.14). Store at room temperature in a tightly stoppered polyethylene bottle wrapped with aluminium foil. Die reagent is stable for at least a week. 

A 3 mL volume of the oxidizing reagent (or 1 portioning spoon of the commercial oxidation reagent Oxisolv, Merck) is added to SOmL of sample and the mixture is autoclaved for 30min. From the total volume of SSmL (or SOmL if Oxisolv is used) of oxidized sample, 5.0 mL are withdrawn for the determination of total nitrogen as nitrate (nitrite), so that 50 mL (45 mL, respectively) remain for the determination of total phosphorus as phosphate. Die 5 mL portion is diluted to SOmL, and analysed for nitrate manually or by flow-analysis (see Section 10.2.9.6). 

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Various oxidation reagents have been used iodine (148, 149). ammonium persulfate (149). and HIO4 (149). Unsymmetrical disulfides... 

The oxidation of 2- and 5-sulfides is usually performed in acetic acid and 30% hydrogen peroxide (213, 229, 263, 345-350) Or with m-chloroperbenzoic acid (341). Ary] (8, 272. 349, 351-353) and alkyl sulfones (129, 203, 214, 270, 274, 275) are thus obtained in good yields. Other oxidative reagents such as KMn04 (7, 273) or CrO (7) in acetic add have also been used. 

Thiazolylsulfides are reactive toward oxidizing reagents, yielding the corresponding 5-sulfones (158) (Scheme 83) (229. 346-349, 353. 382),... 

Alkylthio groups are oxidized to sulfoxides by H2O2 and readily by various oxidizing reagents to sulfones, e.g. in the imidazole series. The SR group is replaced by hydrogen with Raney nickel, and dealkylation is possible, e.g. of 3-alkylthio-l,2-dithiolyliums to give... 

Sulfonyloxazindines as aprollc neutral oxidizing reagents oxidainn of amines, sulfides, selenides and asymmetric oxidation. 

DESS - MARTIN Oxidizing Reagent Oxidation of alcohols to aldehydes or ketones by means of penodinanes. 

LEY - GRIFFITH Oxidation reagent Oxidation ol alcotwls to caitxnyl compounds with a pemjthenate catalyst and N-methylmorpholine - N-oxIde (NMO), In the presence of other functional gmups... 

Aluminium fluoride (anhydrous) [7784-18-4] M 84.0, m 250°. Technical material may contain up to 15% alumina, with minor impurities such as aluminium sulfate, cryolite, silica and iron oxide. Reagent grade AIF3 (hydrated) contains only traces of impurities but its water content is very variable (may be up to 40%). It can be dried by calcining at 600-800° in a stream of dry air (some hydrolysis occurs), followed by vacuum distn at low pressure in a graphite system, heated to approximately 925° (condenser at 900°) [Henry and Dreisbach J Am Chem Soc 81 5274 1959]. 

Bis(3,4-diethyl-2-pyrrolylmethyl)-3,4-dietliyl-l//-pyrrole (2), prepared in situ from the di-t-butylester of the 5,5 -dicarboxylic acid (/), reacts with 4//-1,2,4-triazole-3,5-dialdehyde (3) in di-chloromethane in the presence of trifluoroacetic acid and 2,3-dichloro-5,6-dicyano-/)-benzoquino-ne as an oxidation reagent. Dark blue crystals are obtained after chromatographic purification. The dark violet chloroform solution fluoresces purple at 360 nm and gives the NMR experiments 39. Which compound and which tautomer of it has been formed ... 

A variety of oxidative reagents can be used to convert 17-hydroxypregnanes containing an additional oxygen function at C-20 into 17-ketoandrostanes. Among the most widely used have been chromium trioxide, lead tetraacetate, periodic acid and sodium bismuthate. 

A very common oxidizing reagent is peroxytrifluoroacetic acid, which is usually generated in situ from trifluoroacetic acid [29, 30, 31] or trifluoroacetic anhydride [32, 33, 34] and hydrogen peroxide Peroxytrifluoroacetic acid is one of the most efficient epoxidizing reagents [35] It can be used to prepare epoxides... 

A useful oxidizing reagent is silver(III) tristrifluoroacetate which can be generated from silver peroxide (AgO) and a tnfluoroacetic acid-tnfluoroacetic anhydride mixture [5f] This reagent readily oxidizes alicyclic and bicyclic hydro... 

Lcad(rV) trifluoroacetate is a strong electrophilic and oxidizing reagent It IS a valuable reagent for the hydroxylatton of aromatic compounds [5S, 59] Lead(IV) trifluoroacetate also reacts with silylated benzenes with the exclusive formation of the corresponding trifluoroacetate esters [59] (equation 28)... 

Like the reaction of ketones, the interaction of triflic anhydride with thiourea and substituted thioureas also gives dicationic triflates (equations 40 and 41) however, two sulfur atoms form the bndge in this case This result indicates that triflic anhydride is acting as an oxidizing reagent toward thiourea [89]. 

The whole sequence of reactions represents a tour de force in the elegant manipulation of extremely reactive compounds. F3CIO2 is a violent oxidizing reagent but forms stable adducts by fluoride ion transfer to Lewis acids such as BF3, AsF5 and PtFe. The structures of F3CIO2 and [F2C102] have C2v symmetry as expected (Fig. 17.26e and i). 

Many people view the Skraup/Doebner-von Miller reaction as the worst witch s brew of all the heterocyclic syntheses. The reaction can be violently exothermic. A variety of oxidizing reagents and additives have been added in an effort to improve yields, including iron (III) and tin (IV) salts, nitrobenzenes, iodine and various acids such as boric and arsenic. Cohn s conditions for the Skraup reaction using an iron salt and boric acid in concentrated sulfuric acid are frequently employed. ... 

Entiy Oxidizing Reagent Reaction Conditions Yield (%) of ... 

The chromic acid oxidizing reagent is prepared by dissolving 13.4 g of chromium trioxide in 25 ml of water. To this solution is added 12 ml of concentrated sulfuric acid. An additional minimum quantity of water is added if necessary to dissolve any precipitated salts. 

In all the alkene addition reactions we ve seen thus far, the carbon-carbon double bond has been converted into a single bond but the carbon skeleton has been left intact. There are, however, powerful oxidizing reagents that will cleave C=C bonds and produce two carbonyl-containing fragments. 

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