Pyrolysis peroxides

The process starts from tricyclohexylidene triperoxide which is obtained by oxidation of cyclohexanone with hydrogen peroxide. Pyrolysis leads to a mixture of 1,16-hexadecanolide and cyclopentadecane. The latter is oxidized by oxygen under boric acid catalysis to cyclopentadecanol which is subsequently oxidized to cyclopentadecanone [124,124a]. 

Anhydride manufactured by acetic acid pyrolysis sometimes contains ketene polymers, eg, acetylacetone, diketene, dehydroacetic acid, and particulate carbon, or soot, is occasionally encountered. Polymers of aHene, or its equilibrium mixture, methylacetylene—aHene, are reactive and refractory impurities, which if exposed to air, slowly autoxidize to dangerous peroxidic compounds. 

Isoprene (2-methyl-1,3-butadiene) can be telomerized in diethylamine with / -butyUithium as the catalyst to a mixture of A/,N-diethylneryl- and geranylamines. Oxidation of the amines with hydrogen peroxide gives the amine oxides, which, by the Meisenheimer rearrangement and subsequent pyrolysis, produce linalool in an overall yield of about 70% (127—129). 

Methylsuccinic acid has been prepared by the pyrolysis of tartaric acid from 1,2-dibromopropane or allyl halides by the action of potassium cyanide followed by hydrolysis by reduction of itaconic, citraconic, and mesaconic acids by hydrolysis of ketovalerolactonecarboxylic acid by decarboxylation of 1,1,2-propane tricarboxylic acid by oxidation of /3-methylcyclo-hexanone by fusion of gamboge with alkali by hydrog. nation and condensation of sodium lactate over nickel oxide from acetoacetic ester by successive alkylation with a methyl halide and a monohaloacetic ester by hydrolysis of oi-methyl-o -oxalosuccinic ester or a-methyl-a -acetosuccinic ester by action of hot, concentrated potassium hydroxide upon methyl-succinaldehyde dioxime from the ammonium salt of a-methyl-butyric acid by oxidation with. hydrogen peroxide from /9-methyllevulinic acid by oxidation with dilute nitric acid or hypobromite from /J-methyladipic acid and from the decomposition products of glyceric acid and pyruvic acid. The method described above is a modification of that of Higginbotham and Lapworth. ... 

Mercury-sensitized irradiation of 1,2,3-triphenylisoindole (65) in the presence of oxygen gives a peroxide (103). This peroxide is relatively stable compared with the peroxide (104) derived from similar oxidation of 1,3-diphenylisobenzofuran and can be reconverted to the isoindole (65) by pyrolysis or by treatment with zinc and acetic acid. Reduction of 103 under mild conditions affords o-dibenzoylbenzene (46) and aniline. Aerial oxidation of 47 gives 46 and methylamine, presumably via a peroxide intermediate similar to 103. °... 

Disulfides can be prepared by treatment of alkyl halides with disulfide ions and also indirectly by the reaction of Bunte salts (see 10-41) with acid solutions of iodide, thiocyanate ion, or thiourea, or by pyrolysis or treatment with hydrogen peroxide. Alkyl halides also give disulfides when refluxed with sulfur and NaOH, and with piperidinium tetrathiotungstate or piperidinium tetrathiomolybdate. ... 

Pyrolysis of the phosphorodichloridothioate (59) at 550 °C gives mainly dibenzothiophen and a smaller amount of the cyclic phosphonochlorido-thioate (60). Thermal decomposition of di-t-butyl peroxide in triethyl phosphate gives rise to diethyl methyl phosphate in a reaction which may be interpreted as resulting from attack of methyl radical on the phosphoryl oxygen. An extension of this mechanism accounts for the formation of (61) from tri-isopropyl phosphate under the same conditions. 

Intensification can be achieved using this approach of combination of cavitation and advanced oxidation process such as use of hydrogen peroxide, ozone and photocatalytic oxidation, only for chemical synthesis applications where free radical attack is the governing mechanism. For reactions governed by pyrolysis type mechanism, use of process intensifying parameters which result in overall increase in the cavitational intensity such as solid particles, sparging of gases etc. is recommended. 

Oxaziranes are in a real sense active oxygen compounds and exhibit many reactions grossly analogous to those of organic peroxides. Thus they undergo one electron transfer reaction with ferrous salts and on pyrolysis they are converted to amides. Oxaziranes are also useful synthetic intermediates since in appropriate cases they may be isomerized to aromatic nitrones which are a convenient source of N-alkylhydroxylamines. The reaction of oxaziranes with peracids also provides a source of nitrosoal-kanes and is in many instances the method of choice for preparation of these compounds. ... 

The usual sources used for the homolytic aromatic arylation have been utilized also in the heterocyclic series. They are essentially azo- and diazocompounds, aroyl peroxides, and sometimes pyrolysis and photolysis of a variety of aryl derivatives. Most of these radical sources have been described in the previous review concerning this subject, and in other reviews concerning the general aspects of homolytic aromatic arylation. A new source of aryl radicals is the silver-catalyzed decarboxylation of carboxylic acids by peroxydisulfate, which allows to work in aqueous solution of protonated heteroaromatic bases, as for the alkyl radicals. 

It is also possible to produce covalently bonded alkyl MLs on Si(l 11) surfaces using a variety of chemical reactions with passivated H-terminated Si(l 11), but the preparation methods are more complex than the immersion strategy in part due to the higher reactivity of silicon. This is a major achievement because it allows direct coupling between organic and bio-organic materials and silicon-based semiconductors. Both pyrolysis of diacyl peroxides (Linford Chidsey, 1993) and Lewis acid-catalyzed hydrosilylation of alkenes and direct reaction of alkylmagnesium bromide (Boukherroub et al, 1999) on freshly prepared Si(lll)-H produce surfaces with similar characterishcs. These surfaces are chemically stable and can be stored for several weeks without measurable deterioration. Thienyl MLs covalently bonded to Si(l 11) surfaces have also been obtained, in which a Si(l 11)-H surface becomes brominated, Si(lll)-Br, and is further reacted with lithiated thiophenes (He etal, 1998). 

Homolytic substitution has been little studied, and work has been confined to the reaction of dibenzofuran with carboxymethyl radicals produced from acetyl peroxide or di-tcrt-butyl peroxide in boiling acetic acid or by pyrolysis of chloroacetylpolyglycolic acids. The method of analysis of the resultant mixture of 1- (55%), 4- (30%), and 3-dibenzofuranacetic acid (15%) was crude, but the results were in accord with simple HMO calculations. The amount of the 1-substituted product is perhaps surprising in view of the steric hindrance at this position. 

T0387 Hydrocarbon Technologies, Inc., Recovered Oil Pyrolysis and Extraction (ROPE) T0388 Hydrogen Peroxide In Situ Bioremediation—General... 

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