Carboxylic acids hypochlorite

Nickel peroxide is a solid, insoluble oxidant prepared by reaction of nickel (II) salts with hypochlorite or ozone in aqueous alkaline solution. This reagent when used in nonpolar medium is similar to, but more reactive than, activated manganese dioxide in selectively oxidizing allylic or acetylenic alcohols. It also reacts rapidly with amines, phenols, hydrazones and sulfides so that selective oxidation of allylic alcohols in the presence of these functionalities may not be possible. In basic media the oxidizing power of nickel peroxide is increased and saturated primary alcohols can be oxidized directly to carboxylic acids. In the presence of ammonia at —20°, primary allylic alcohols give amides while at elevated temperatures nitriles are formed. At elevated temperatures efficient cleavage of a-glycols, a-ketols... 

Early attempts to prepare 5-amino- and 5-acylaminobenzofuroxans by hypochlorite oxidation of the corresponding o-nitroanilines met with failure. Pyrolysis of the appropriate azide, however, gives 5-dimetliylamino- and 5-acetamidobenzofuroxan, whereas urethans of type (33) are produced by Curtius degradation of the 5-carboxylic acid. Controlled hydrolysis of the acetamido compound and the... 

Due to the -OCH2COOH group the ether carboxylic acids have a good chemical and thermal stability. Therefore they can be used in formulations containing oxidizing agents such as hypochlorite and peroxide [61,64]. 

Still another method for the conversion of halides to acid derivatives makes use of Na2Fe(CO>4. As described in 10-112, primary and secondary alkyl halides and tosylates react with this reagent to give the ion RFefCO) (142) or, if CO is present, the ion RCOFe(CO)4 (143). Treatment of 142 or 143 with oxygen or sodium hypochlorite gives, after hydrolysis, a carboxylic acid. " Alternatively, 142 or 143... 

The reaction can also be effected with hypochlorite ion, and this constitutes a useful method for converting methyl ketones to carboxylic acids. 

Methyl ketones are degraded to the next lower carboxylic acid by reaction with hypochlorite or hypobromite ions. The initial step in these reactions involves base-catalyzed halogenation. The a-haloketones are more reactive than their precursors, and rapid halogenation to the trihalo compound results. Trihalomethyl ketones are susceptible to alkaline cleavage because of the inductive stabilization provided by the halogen atoms. 

Oxidation of —CHtOH — —CHO (cf., 12,479-480). This oxidation can be effected in high yield with sodium hypochlorite (slight excess) in buffered H20/ CH2C12 with this nitroxyl radical and KBr as the catalysts.1 The oxidation is exothermic, and the temperature should be maintained at 0-15° with a salt-ice bath. Saturated primary alcohols are converted to aldehydes in 88-93% yield yields are lower in the case of unsaturated substrates. Addition of quaternary onium salts permits further oxidation to carboxylic acids. 

Thus, P.Y.108 is commercially produced by heating l,9-anthrapyrimidine-2-carboxylic acid with 1-aminoanthraquinone and thionyl chloride in a high boiling solvent, such as o-dichlorobenzene or nitrobenzene, to 140 to 160°C. The product is separated, washed with methanol, and residual solvent removed by steam distillation. The aqueous suspension is then boiled down with sodium hypochlorite solution. 

Catalysed oxidation of non-activated haloalkanes by hypochlorite provides an attractive low-cost and convenient procedure for their conversion into carbonyl compounds [6] primary haloalkanes produce carboxylic acids and secondary haloalkanes are converted into ketones (Table 10.12). Secondary amines are oxidized to ketones under analogous conditions, whereas primary amines yield nitriles (Table 10.13) [1,2], o-Nitroanilines are oxidized to benzofurazan-1-oxides [15]. 

Nickel(lll) oxide, prepared from a nickel(ii) salt and sodium hypochlorite, is used for the oxidation of alkanols in aqueous alkali [46]. Residual nickel(Ii) oxide can be re-activated by reaction with sodium hypochlorite. Nickel oxides have also long been used in the manufacture of the positive pole in the Edison nickel-iron rechargeable battery, now largely superseded by die lead-acid accumulator, and in the Jungner nickel-cadmium batteries used as button cells for calculators [47]. Here, prepared nickel oxide is pressed into a holding plate of perforated nickel. Such prepared plates of nickel(lli) oxide have been proposed as reagent for the oxidation, in alkaline solution, of secondary alcohols to ketones and primary alcohols to carboxylic acids [48]. Used plates can be regenerated by anodic oxidation. 

The reactions catalyzed by Lewis acids are conducted for 10-20 hours at — 20 C to give hypochlorites in almost quantitative yield.82 Chlorine monofluoride activated by hydrogen fluoride to enhance its electrophilicity transforms the carbonyl function in esters of carboxylic acids to a difluoromethyl group. The reactions are carried out by passing 2molar equivalents of chlorine monofluoride gas through a solution of the ester in an equal volume of hydrogen fluoride at - 70 to - 30°C.83... 

CHLORINE OXYGENACIDS AND SALTS - DICHLORINEMONOXIDE,HYPOCHLOROUSACID, AND HYPOCHLORITES] (Vol 5) Perfluorinated carboxylic acids... 

The two-phase epoxidation of alkenes by hydrogen peroxide in water-dichloromethane system, catalysed by manganese(III)-porphyrin, is strongly accelerated by addition of catalytic amounts of a carboxylic acid and lipophilic imidazole or pyridine axial ligand365,366. Manganese(III)-porphyrin bound to colloidal anion-exchange particles is more active in the selective epoxidation of styrene by aqueous hypochlorite than the same catalyst in aqueous solution367. 

Immobilized TEMPO has been used for the one-pot oxidation of alcohols to carboxylic acids as well.26 For this purpose TEMPO resin 1 was combined with two ion-exchange resins loaded with chlorite anions and hydrogen phosphate in the presence of catalytic amounts of potassium bromide and sodium hypochlorite in solution. The reaction required work-up for the removal of salts, but tolerated several protecting schemes and afforded pure products in good to excellent yields. The reaction is initiated by catalytic TEMPO oxidation of alcohols to aldehydes driven by dissolved hypochlorite followed by oxidation to the carboxylic acids effected by chlorite. 

A solution is prepared from 3.3 g (8.5 mmol) of 6-benzyloxy-4-methoxymethyl-l,2,3,4-tetrahydro-p-carboline-3-carboxylic acid isopropyl ester in 150 ml of methylene chloride, combined under argon with 3.9 ml of triethylamine, and cooled to -15°C. At this temperature, a solution of 3.2 ml (25.6 mmol) of t-butyl hypochlorite in 50 ml of methylene chloride is added dropwise without delay to this solution. After the adding step is completed, the mixture is stirred for another 10 min, combined with 2.6 ml of triethylamine, and agitated for 2 hours at room temperature. Subsequently, the mixture is concentrated to one-half thereof and extracted once by shaking with dilute ammonia solution. The organic phase is dried, filtered, and concentrated. The residue is chromatographed over silica gel with methylene chloride acetone=4 l as the eluent. Recrystallization from ethyl acetate gives 1.1 g (35% yield) of 6-benzyloxy-4-methoxymethyl-p-carboline-3-carboxylic acid isopropyl ester, m.p. 150-151°C. 

The 2,2,6,6-tetramethylpiperidinoxyl (TEMPO) radical was first prepared in 1960 by Lebedev and Kazarnovskii by oxidation of its piperidine precursor. TEMPO is a highly persistent radical, resistant to air and moisture, which is stabilized primarily by the steric hindrance of the NO-bond. Paramagnetic TEMPO radicals can be used as powerful spin probes for investigating the structure and dynamics of biopolymers such as proteins, DNA, and synthetic polymers by ESR spectroscopy [7]. A versatile redox chemistry has been reported for TEMPO radicals. The radical species can be transformed by two-electron reduction into the respective hydroxyl-amine or by two-electron oxidation into the oxoammonium salt [8]. One-electron oxidations involving oxoammonium salts have also been postulated [9]. The TEMPO radical is usually employed under phase-transfer conditions with, e.g., sodium hypochlorite as activating oxidant in the aqueous phase. In oxidations of primary alcohols carboxylic acids are often formed by over-oxidation, in addition to the de-... 

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