Oxidative procedures for

The following procedure may prove to be one of the largest advances in the field of MDMA chemistry since the perfection and dissemination of the Wacker oxidation procedure for producing MDP2P. This reaction is based on a published process that somehow has escaped discovery by underground chemistry until... 

B. General Oxidation Procedure for Alcohols. A sufficient quantity of a 5% solution of dipyridine chromium (VI) oxide (Note 1) in anhydrous dichloromethane (Note 7) is prepared to provide a sixfold molar ratio of complex to alcohol. This excess is usually required for complete oxidation to the aldehyde. The freshly prepared, pure complex dissolves completely in dichloromethane at 25° at 5% concentration to give a deep red solution, but solutions usually contain small amounts of brown, insoluble material when prepared from crude complex (Note 8). The alcohol, either pure or as a solution in anhydrous methylene chloride, is added to the red solution in one portion with stirring at room temperature or lower. The oxidation of unhindered primary (and secondary) alcohols proceeds to completion within 5 minutes to 15 minutes at 25° with deposition of brownish-black, polymeric, reduced chromium-pyridine products (Note 9). When deposition of reduced chromium compounds is complete (monitoring the reaction by gas chromatography or thin-layer chromatography analysis is helpful), the supernatant liquid is decanted from the (usually tarry) precipitate and the precipitate is rinsed thoroughly with dichloromethane (Note 10). 

B. Oxidation procedure for the small-scale experiments. The required amounts of hexan-l-ol, AA-TEMPO, Mg(N03)2, NBS and HOAc were loaded in the reactor and the flask was connected to the volumetric manifold. The flask was flushed three times with oxygen and immersed in the thermostated water bath held at the reaction temperature for two minutes to equilibrate the system. The oxygen was admitted to the reaction pressure and the continuous monitoring of the oxygen uptake initiated and recorded against the time. After the reaction was completed the product composition was analyzed by GC using dioxane as an internal standard. 

Among the oxidative procedures for preparing azo compounds are oxidation of aromatic amines with activated manganese dioxide oxidation of fluorinated aromatic amines with sodium hypochlorite oxidation of aromatic amines with peracids in the presence of cupric ions oxidation of hindered aliphatic amines with iodine pentafluoride oxidation of both aromatic and aliphatic hydrazine derivatives with a variety of reagents such as hydrogen peroxide, halogens or hypochlorites, mercuric oxide, A-bromosuccinimide, nitric acid, and oxides of nitrogen. 

Moreover, we believe that the azo form helps in stabilizing several of the reactive copper complexes involved in this catalytic cycle such as the hydroxy copper complex 17. Thus, we surmise that this novel catalytic, aerobic oxidation procedure for alcohols into carbonyl derivatives proceeds via a dehydrogenation mechanism and relies on the effective role of hydrazine or azo compounds as hydrogen shuttles and stabilizing ligands for the various copper complexes (20). 

An alternative interesting approach, which is based on the Mukaiyama reduction/oxidation procedure for peptide bond formationt uses tributylphosphine in the presence of diphenyl diselenide and the N-protected annino acid for in situ condensation with the a-azido compound. The phenyl carboselenolate is formed as an activated carboxylic add and the resulting benzeneselenol reduces the azide to the amine for reaction with the active ester. 

The classical silica gel chromatographic method for determination of percent olefins in shale oils was studied and found wanting, mainly because of cross-contamination from high levels of olefins and heteroatom-containing compounds. This paper describes a new hydroboration/oxidation procedure for olefins, and reports its use in hydrocarbon-type analysis of both whole shale oils and distillate fractions. Percent composition values for three whole oils ranged as follows saturates, 13-26 olefins, 16-20 aromatics, 5-14 polar compounds, 41S2. A discussion of IR analysis for relative amounts of specific olefin types such as terminal, internal trans, and methylene structures is included. 

Amines oxides. Procedures for the preparation of an aliphatic amine (4), its conversion to the amine oxide (5), and pyrolysis of this to methylenecyclohexane (6, Cope reaction) are shown in the formulation. A homogeneous solution of 0.35... 

This method of quinoxaline di-JV-oxide formation is known as the Beirut reaction and is extremely useful, particularly in view of the limitations of direct oxidative procedures for preparing di-N-oxides. Probably several hundred quinoxaline di-iV-oxides have been prepared in this way. Only a selection of those exemplified in the patent literature are included in the table at the end of this chapter. Valuable reviews on the conversion of benzofuroxans into quinoxaline di-JV-oxides have been written by Haddadin and Issidorides and by Ley and Seng. ... 

Friend, M.T., Smith, C.A. and Wishart, D. (1977) Ashing and wet oxidation procedures for the determination of some volatile trace metals in foodstuffs and biological materials by AAS. Atom. Abs. Newsl., 16, 46-49. 

Watling, R.J. (1978) A simple oxidation procedure for biological material prior to analysis for mercury. Anal. Chim. Acta, 99, 357-360. 

Cycloadducts formed from TADs are often modified and then subjected to the hydrolysis-oxidation procedure. For example, hydrolysis and oxidation of 473, the initial PTAD adduct to 1,2-diisopropylidenecyclobutane, gives labile azoalkane 474. However, thermal isomerization of the initial cycloadduct give 475, which then provides 476 in the usual way (Scheme 81) (76JA1875). 

De Bellefon et al. reported a safe and straightforward aerobic flow oxidation procedure for aliphatic aldehydes to their corresponding carboxylic acids [52]. The procedure was characterized by its simpUcity and mildness. Neither additional... 

Full details of the catalytic oxidative procedure for cleaving 1,2 5,6-di-O-isopropylidene-D-raannitol to 2,3-0-isopropylidene-D-glyceraldehyde using a bismuth catalyst have been published (see Vol. 15, p, 167). ... 

A dichromate oxidation procedure for table wines was proposed by S michon and Flanzy (1932b). No data on the accuracy of the procedure were given. A new procedure by Krause (1948) is based on the solubility of calcium lactate and acetate in anhydrous methyl alcohol. The lactate and acetate were precipitated as silver salts and ashed, and the alkalinity of the ash was determined. By subtracting the acetic acid, the lactic acid content can be calculated. The procedure is said to be satisfactory for red and white wines, even if they contain sugar. 

Though manual determinations of nutrients are still in use, the majority of samples are analysed by automated flow-analyses. The oxidation procedures for the determination of total nitrogen, phosphorus and silicon as presented in the previous editions of this book, have thus been adapted to subsequent flow-analysis of inorganic nutrients without modifications to the manifolds or reagents. 

It was observed that organically bound phosphorus is completely decomposed to phosphate when oxidized with persulphate in an alkaline medium. Furthermore, more than 60 % of condensed phosphates are hydrolyzed. As concentrations of polyphosphates are negligible in most natural waters, a simultaneous oxidation procedure for organic phosphorus and nitrogen compounds has been developed by Korolejf (1977). Valderrama (1981) compared the procedure with former methods using separate determinations. In the simultaneous oxidation, the pH of the reaction starts at ca. 9.7 and ends at 4-5. These conditions are obtained by a boric acid-NaOH system. In seawater samples no precipitation is formed when the oxidation mixture is added. At elevated temperatures a precipitation is formed, which, however, dissolves as oxidation proceeds. 

Pujo-Pay M. and Raimbault P. 1994. Improvement of the wet-oxidation procedure for simultaneous determination of particulate organic nitrogen and phosphorus collected on filters. Mar. Ecol. Prog. Ser. 105 203-207. 

Even though detailed studies of the oxidation of 6-isophorone have led to highly selective homogeneous and some heterogeneous oxidation procedures for the synthesis of KIP, all of them still require the isomerisation of a-isophorone to yS-isophorone. As a-isophorone is readily available and is the thermodynamically more stable isomer, and to avoid this additional and thermodynamically unfavoured reaction, intense efforts have been made to find a direct oxidation of a-isophorone to KIP. 

The standard oxidation procedure, for instance, provides phenol 129. 

Kabalka, G.W. and Hedgecock, H.C. (1975) Mild and convenient oxidation procedure for the conversion of organoboranes to the corresponding alcohols. The Journal of Organic Chemistry, 40,1776-1779. 

Sharif M, Gong J-L, Langta- P, Beller M, Wu X-F (2014) A novel oxidative procedure for the synthesis of benzamides from styrenes and amines under metal-free conditions. Chem Commun 50(36) 4747-4750... 

Danishefsky has developed a mild oxidative procedure for the conversion of highly functionalized alkenyl boronates (obtained by alkenyl boronate cross-metathesis) to the corresponding aldehydes with trimethylamine N-oxide that was found to be compatible with hydroxyl, ketone and acid functionalities present in alkenyl boronates without protection [109]. For example, by using this methodology, it was possible to oxidize the iodoalkenyl boronate intermediate 133 to the aldehyde 134 that was subjected to intramolecular Nozaki-Kishi macrocyclization yielding 11-hy-droxy deoxyepothilone precursor 135 in 40% yield (Scheme 3.71). 

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