Benzoyl peroxide, oxidation

Scheme 28 outlines Eschenmoser s model corrin synthesis. The enamide (310) was treated with KCN to give (311), and this gave the thiolactam (312) when treated with phosphorus pentasulfide. Benzoyl peroxide oxidation yielded the disulfide (313), and in the presence of the enamide (310) this gave the bicyclo thio-bridged compound (314). Sulfur extrusion, by this time a standard procedure (Scheme 22), provided the vinylogous amidine (315)... 

Indoxyls (140) have been reported to be oxidized under a variety of conditions to indolones (158). However, the literature claims are conflicting. Ruggli claimed to oxidize 2-phenyl-6-nitroindoxyI to the corresponding indolone with nitrous acid, but attempts to repeat this reaction failed.Benzoyl peroxide oxidized 2-(4-aminophenyl)-4,6-dinitroindoxyl to the corresponding indolone, but methyl indoxyl-2-carboxylate to the diindoxyl (141 R = COjMe). Isatogens are reduced under a variety of conditions to a number of different products which include some indolones (158 R = Ph, 4-methoxyphenyl) and indolone hydrates (139 R = COjMe, 2-pyridyl R = H) for a detailed discussion see Section II1,B and Table I. 

The products from diacyl and benzoyl peroxide oxidation depend very much on the structure of the tertiary amine The initial... 

Derivative Formation. Hydrogen peroxide is an important reagent in the manufacture of organic peroxides, including tert-huty hydroperoxide, benzoyl peroxide, peroxyacetic acid, esters such as tert-huty peroxyacetate, and ketone derivatives such as methyl ethyl ketone peroxide. These are used as polymerization catalysts, cross-linking agents, and oxidants (see Peroxides and peroxide compounds). 

Campaigne et al. have used 3-thenyl bromide obtained by benzoyl peroxide-catalyzed, side-chain bromination of 3-methylthiophene with A -bromosuccinimide, as a starting material for 3-substituted thiophenes. - 22 3-Methylthiophene is now prepared commercially from itaconic acid. The reactive halogen in 3-thenyl bromide could be directly reacted with a variety of nucleophiles, such as cyanide, or malonate, to give more complex 3-substituted compounds. 3-Thenyl bromide was converted by the Sommelet reaction to 3-thio-phenealdehyde which, with silver oxide, was oxidized to 3-thio-... 

Linalol yields a somewhat remarkable compound, by artificial oxidation which appears also to be formed naturally. This body is termed linalol monoxide, and has the formula CjoHjgO. It was first found in oil of linaloe by Schimmel Co., and it is probably to be explained by the oxidation of the essential oil on exposure to the air at the surface of the trunk of the tree. It has been prepared artificially by Prileshajeff by oxidising linalol with hydrated benzoyl peroxide. By further oxidation with the same reagent, he obtained linalol dioxide. 

ACPA azobis(4-cyanopentanoic acid) AIBN azobis isobutyronitrile) BPO benzoyl peroxide DVB divinyl benzene, EGA 2-ethylcyano-acrylate HPC hydroxypropyl cellulose MMA methyl methacrylate PAAc polyacrylic acid PEI polyethyleneimine, PEO/PPO polyethylene oxide/polypyropylene oxide copolymer PVME polyvinylmethylether PVP polyvinylpyrrolidone K-30 DMSO dimethylsulfoxide PGA polyglutaraldehyde CMS chloromethylstyrene PMMA-g-OSA polymethylmethacrylate grafted oligostearic acid. 

In the oxidative Eschenmoser sulfide contraction (Scheme 11), thioamide 59 is oxidized by benzoyl peroxide to give either a symmetrical disulfide or the O-benzoate of the thiolactam-S-oxide. In any event, the once-nucleophilic thioamide sulfur atom is now forced to adopt the role of electrophile a reactivity umpolung has, in effect, been achieved.13 The nucleophilic enamide 65 attacks the sulfur atom leading to the formation of sulfur-bridged intermediate 66. The action of a phosphine or a phosphite thiophile on the putative episulfide then gives vinylogous amidine 67. 

Horner and Jurgens39 reported that benzoyl peroxides 21 in the presence of sulphides decompose to give sulphoxides and a-acyloxysulphides 22 (equation 8). The latter compounds are undoubtedly formed as a result of the Pummerer reaction. The oxidation reaction leading to sulphoxides has been shown to be an ionic process40. However, till now it has not found wider synthetic applications. Ganem and coworkers41 showed that 2-hydroperoxyhexafluoro-2-propanol 23 formed in situ from hexafluoroacetone and... 

Wheat flour typically becomes white by means of normal oxidation in air during a few weeks of storage. To speed up the process, manufacturers use benzoyl peroxide as a bleaching agent. Sulfur dioxide is a reducing bleaching agent that is used to preserve dried fruits. 

Secondary amines (R2NH) are oxidized to hydroxylamines (R2NHOH), which are resistant to further oxidation, by dimethyldioxirane and by benzoyl peroxide and NajHPOa. " ... 

The liquids used were 1 1 mixtures of EBA-HV and liquid methacrylate which also contained dihydroxyethyl-p-toluidine as the accelerator. Both mono- and di-methacrylates were used. The benzoyl peroxide initiator was included in the EBA zinc oxide/silanized (1 1) glass powder. These polymer cements set 5 to 10 minutes after mixing. Since there is a substantial amount of monomer in the liquid (50%) the contribution of the polymer to the strength of the cement must be considerable. Brauer Stansbury (1984b) suggested that the two matrices, the polymer matrix and the salt matrix, may be interpenetrating but separation of the two phases is likely. 

Larger substituents or fewer Si-H groups lead to compounds that are more stable and which may be distilled in air, for example, c-C6HuSiH3 and Bu"3SiH (11). Although Ph3SiH is stable in air, it is oxidized by 02 in benzene solution in the presence of benzoyl peroxide... 

Local overheating and ignition occurred when solid benzoyl peroxide was put into a beaker which had been rinsed out with methyl methacrylate. Contact between the peroxide, a powerful oxidant and radical source, and oxidisable or polymerisable materials should only be under controlled conditions. 

D. Other Primary Oxidants, Mechanisms of Benzoyl Peroxide... 

The flow-cell design was introduced by Stieg and Nieman [166] in 1978 for analytical uses of CL. Burguera and Townshend [167] used the CL emission produced by the oxidation of alkylamines by benzoyl peroxide to determine aliphatic secondary and tertiary amines in chloroform or acetone. They tested various coiled flow cells for monitoring the CL emission produced by the cobalt-catalyzed oxidation of luminol by hydrogen peroxide and the fluorescein-sensitized oxidation of sulfide by sodium hypochlorite [168], Rule and Seitz [169] reported one of the first applications of flow injection analysis (FTA) in the CL detection of peroxide with luminol in the presence of a copper ion catalyst. They... 

Methyl methacrylate 4-Methylnitrobenzene 2- Methylpyridine Methylsodium Molybdenum trioxide Naphthalene 2-Naphthol Air, benzoyl peroxide Sulfuric acid, tetranitromethane Hydrogen peroxide, iron(II) sulfate, sulfuric acid 4-Chloronitrobenzene Chlorine trifluoride, interhalogens, metals Chromium trioxide, dinitrogen pentaoxide Antipyrine, camphor, phenol, iron(III) salts, menthol, oxidizing materials, permanganates, urethane... 

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