Oxidation using KMnO

Such carbonyls may be further oxidized using potassium permanganate (KMnO and perchloric acid (HCIO4) to convert all of these groups into carboxylic acids. Once functionalized in this manner, the nanotubes can be fully dispersed in aqueous systems. Kordas et al. (2006) used these derivatives to print nanotube patterns on paper or polymer surfaces to create conductive patterns for potential use in electronic circuitry. The carboxylates also may be used as conjugation sites to link other ligands or proteins to the nanotube surface using a carbodiimide reaction as previously discussed (Section 1, this chapter Chapter 2, Section 1.11 Chapter 3, Section 1). 

Alkyne oxidation reactions are of little value now but were used bi > tortcally in Uie structure -detemiination of substances isolated fron) nau-ral sources. For example, the location of the triple bond in the chain of tariric acid was established by finding that oxidation with KMnO., gax e dodecar. c add and hexanedioic acid ... 

Scheme 14.51 Chemoselective oxidation of alcohols using KMnO in [bmim][BF ]...

C. The conversion is an oxidation reaction, and can be accomplished by using KMnO,. 

The second method of carboxylation also used KMnO as an oxidation agent but, in this case, 18-crown-6-ether was employed as the phase transfer agent and KMnO was employed as the dissociation agent. A reasonable retention of the molecular weight was observed when the pH of the reaction was carefully controlled (Bear et al. 2001 Kurth et al. 2002)... 

Diels-Alder reaction followed by dehydrogenation of the cycloadduct using KMnO supported on alumina under mild conditions has been reported (Scheme 16.20) [21]. Two other dihydroaromatic substrates (cycloadducts shown in the box) that have been oxidized by this method are also... 

It was observed that the most efficient oxidant was KMnO absorbed on a fourfold molar amount of CUSO4.5H2O (100% yield), but attempts were made to oxidize 2-heptanol, under solvent-free conditions, by KMnO alone (i.e., in the absence of the support of an inorganic salt hydrate) were absolutely unsuccessful. Various inorganic salts were tried and yielded varied amounts of the product. The better supports include nickel sulfate (90%), zinc sulfate (74%), and cobalt sulfate (41%) while other supports were not that interesting like magnesium sulfate (12%), calcium sulfate (11%) and barium chloride (3%). Zeolite HZSM-5 was used as a catalyst for the oxidation of alcohols to the corresponding carbonyl compound with chromium trioxide under solvent-free conditions and microwave irradiation (Heravi et al., 1999). 

Oussaid and Loupy (1997) used KMnO impregnated on alumina under micro-wave activation in dry media to oxidize arenes into ketones within 10-30 min instead of several days under conventional conditions. 

Alkyl groups attached to aromatic rings are oxidized more readily than the ring in alkaline media. Complete oxidation to benzoic acids usually occurs with nonspecific oxidants such as KMnO, but activated tertiary carbon atoms can be oxidized to the corresponding alcohols (R. Stewart, 1965 D. Arndt, 1975). With mercury(ll) acetate, allyiic and benzylic oxidations are aJso possible. It is most widely used in the mild dehydrogenation of tertiary amines to give, enamines or heteroarenes (M. Shamma, 1970 H. Arzoumanian. 1971 A. Friedrich, 1975). 

By far the most commonly used oxidation method is the corrected permanganate number test (26) in which the number of mL of 0.1 KMnO consumed by 1 g of oven-dried pulp under specified conditions (kappa number) is deterrnined (TAPPl Historical Method T236 hm-85). Typical kappa numbers for representative pulps are shown in Table 3. 

Germany, Bitterfeld 1920 two-stage rotary kilns heated internally using intermediate grinding of roast oxidation completed within 3—4 h cylindrical monopolar ceUs, 4 m volume undivided con-centric Ni anodes, rod-shaped Fe cathodes unfiltered electrolyte batch operation KMnO crystallizes in ceU electrolysis energy consumption about 700 kWh/1 4,000 27,113... 

Manganate(VI) formed in the initial oxidation process must first be dissolved in a dilute solution of potassium hydroxide. The concentrations depend on the type of electrolytic cell employed. For example, the continuous Cams cell uses 120 150 g/L KOH and 50 60 g/L K MnO the batch-operated Bitterfeld cell starts out with KOH concentrations of 150 160 g/L KOH and 200 220 g/L K MnO. These concentration parameters minimize the disproportionation of the K MnO and control the solubiUty of the KMnO formed in the course of electrolysis. 

Oxidation of Sucrose. Sucrose can be oxidized by HNO, KMnO, and peroxide. Under selected conditions using oxygen with palladium or platinum, the 6- or 6 -hydroxyls can be oxidized to form sucronic acid derivatives (29). 

Ketones are inert to most oxidizing agents but undergo a slow cleavage reaction when treated with hot alkaline KMnO The C-C bond next to the carbonyl group is broken, and carboxylic acids are produced. The reaction is useful primarily for symmetrical ketones such as cyclohexanone because product mixtures are formed from unsymmetrical ketones. 

One other important compound of manganese is potassium permanganate, KMnO . This is an intensely violet-colored material much used as an oxidizing agent in the laboratory. (It is too expensive to use on a large scale in industry, chlorine is more likely to be used.)... 

Potassium permanganate (KMnO ) is a purplish crystal-like oxidizing compound used as an antiseptic and disinfectant to inhibit the growth of harmful skin microorganisms and bacteria. Before antibiotics were available, it was used as a treatment for trench mouth and impetigo. 

Acetonylation.1 In the presence of TiCl or BF3 etherate allyltrimethylsilane undergoes conjugate addition to a,/ -enones. The 5,e-enones formed are converted by ozonation or KMnO K 10 to o-keto aldehydes. Wacker oxidation can be used to obtain methyl ketones. 

X-4 Oxidation of a secondary alcohol requires the use of 3 s r oxidizing agent, cither KMnO and OH or K2Cr,Oi 3,1 H,S04 (the latter is more frequently used). 

Barium. Before the routine use of AAS, Ba was analyzed by emission spectrograph or a KMnO spot test (13). Alkali and alkaline earth metals are analyzed in nitrous oxide/acetylene flames with ionization suppressants such as 1000 ppm Cs. For barium analysis by P CAM 173, background correction must be used whenever greater than 1000 ppm calcium is in the analyte solution. There are strong Ca(0H)2 absorptions and emission at 553.6 nm, which is the barium analytical line. 

SnClf soln. (5 drops). After diluting the aoln. to 50 ml and making pH 5 hy using 1 M NaOH, the V is extracted into an equal volume of O.25 H TTA benzene soln. The V is hack-extracted into 25 ml 6 N HC1 from the benzene soln. After the V (+M-) is oxidized to V(+5) hy 1 M KMnO (5-10 drops), the V is ppted. by 2 ml 6 cupferron aqueous soln. and filtered. Yield - 30. ... 

In addition, it was shown that CuS0,(H20)- mixed with the KMnO, accelerated the oxidation of secondary alcohols. The combination produced an oxidant which was capable of oxidizing alcohols to ketones in high yield and under mild conditions as shown in Table I. Perhaps the most useful feature of the reactions in Table I is the easy workup filtration of the solids and evaporation of the benzene give the product in a satisfactory state of purity. 

Oxidations. Zinc permanganate supported on silica gel is useful for oxidations in organic solvents, usually CHCl, orCH.Ch. Workup involves merely filtration and removal of the solvent. Under comparable conditions, Zn(MnO,), is more reactive than KMnO, MglMnOili exhibits intermediate reactivity. 

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