Amine oxidation with hydrogen peroxide

The heading production of chemical products includes the conversion of allyl alcohol to glycerine with hydrogen peroxide, the production of epoxy-compounds such as epoxy soya oil (plasticizer for PVC) and organic peroxides (e.g. methyl-ethyl-ketone-peroxide, dibenzoylperoxide), which are used as free radical initiators in polymerization processes. The production of amine oxides such as lauryl-dimethyl-amine-oxide with hydrogen peroxide (used as a rinsing agent in dishwashers) is also included. 

The stereochemical course of reduction of imonium salts by Grignard reagents was found to depend on the structure of the reagent 714). Hydro-boration of enamines and oxidation with hydrogen peroxide led to amino-alcohols (7/5). While aluminum hydrogen dichloride reacted with enamines to yield mostly saturated amines and some olefins on hydrolysis, aluminum hydride gave predominantly the unsaturated products 716). 

A heterocyclic ring may be used in place of one of the benzene rings without loss of biologic activity. The first step in the synthesis of such an agent starts by Friedel-Crafts-like acylation rather than displacement. Thus, reaction of sulfenyl chloride, 222, with 2-aminothiazole (223) in the presence of acetic anhydride affords the sulfide, 224. The amine is then protected as the amide (225). Oxidation with hydrogen peroxide leads to the corresponding sulfone (226) hydrolysis followed by reduction of the nitro group then affords thiazosulfone (227). ... 

The most widely employed methods for the synthesis of nitrones are the condensation of carbonyl compounds with A-hydroxylamines5 and the oxidation of A+V-di substituted hydroxylamines.5 9 Practical and reliable methods for the oxidation of more easily available secondary amines have become available only recently.10 11 12 13. These include reactions with stoichiometric oxidants not readily available, such as dimethyldioxirane10 or A-phenylsulfonyl-C-phenyloxaziridine,11 and oxidations with hydrogen peroxide catalyzed by Na2W044 12 or Se02.13 All these methods suffer from limitations in scope and substrate tolerance. For example, oxidations with dimethyldioxirane seem to be limited to arylmethanamines and the above mentioned catalytic oxidations have been reported (and we have experienced as well) to give... 

In general, sulfoximines are accessible by various routes, and most of them involve sulfur oxidation/imination sequences. For example, enantiopure 9 is commonly prepared starting from sulfide 10, which is oxidized with hydrogen peroxide (under acidic conditions) giving sulfoxide 11 (Scheme 2.1.1.1). Subsequent imina-tion of 11 with a mixture of sodium azide and sulfuric acid affords sulfoximine 9 as a racemate. Enantiomer resolution can then be achieved with camphorsul-fonic acid, leading to both enantiomers of 9 with high efficiency [15]. Alternatively, many sulfoximine syntheses start from enantiopure sulfoxides [16, 17], which can be stereospecifically iminated with 0-mesitylenesulfonylhydroxyl-amine (MSH) [18], as shown for the synthesis of sulfoximine (1 )-13 in Scheme 2.I.I.2. 

Compositions and functions of typical commercial products in the 2-alkyl-l-(2-hydroxyethyl)-2-imidazolines series are given in Table 29. 2-Alkyl-l-(2-hydroxyethyl)-2-imidazolines are used in hydrocarbon and aqueous systems as antistatic agents, corrosion inhibitors, detergents, emulsifiers, softeners, and viscosity builders. They are prepared by heating the salt of a carboxylic acid with (2-hydroxyethyl)ethylenediamine at 150—160°C to form a substituted amide 1 mol water is eliminated to form the substituted imidazoline with further heating at 180—200°C. Substituted imidazolines yield three series of cationic surfactants by ethoxylation to form more hydrophilic products quatemization with benzyl chloride, dimethyl sulfate, and other alkyl halides and oxidation with hydrogen peroxide to amine oxides. 

Oxidation with hydrogen peroxide is very popular in pharmaceutical development as a test for oxidative conditions55 (42). The most common reactions with organic compounds are electrophilic attack on amines and sulfides to give N-oxides and sulfoxides or sulfones, respectively, and the slower attack on carbon-carbon double bonds to give epoxides. These reaction are ionic and do not involve radicals ... 

By using this mild and versatile methodology, symmetrical diaryl ethers have been synthesized in a one-pot, two-step procedure starting from arylboronic acids and their partial conversion to the corresponding phenols by oxidation with hydrogen peroxide and a subsequent coupling of the formed phenols with the remaining arylboronic acids upon addition of copper(II) acetate, molecular sieves and triethyl amine (Scheme 7) [22],... 

Figure 3.43 Use of an amine base with hydrogen peroxide to effect aldehyde oxidation.

Tertiary alkylamines can be converted into the corresponding N-oxides with hydrogen peroxide or with peroxy acids." r-Butyl hydroperoxide has also been used in the presence of a catalyst such as VO(acac)2. Sharpless and coworkers have carried out the oxidative kinetic resolution of several p-hy-droxy tertiary amines such as (41) with r-butyl hydroperoxide, titanium(rv) isoprcqtoxide and (-i-)-diiso-propyl tartrate, the titanium(rv) tartrate ratio being ateut 2 1." After 60% conversion, one enantiomer was selectively oxidized, and the other enantiomer could be recovered in good optical purity (Scheme... 

Tertiary amines are also used in the manufacture of amine oxides by the oxidation with hydrogen peroxide. The amine oxides are used in cosmetic preparations for its good foaming properties and mildness to the skin. Another raw material used in the cosmetic industry is the betaines produced by the reaction of a tertiary fatty amine with sodium chloroacetate. The betaines exhibit good foam stability over a wide range of pH, are insensitive to water hardness, and are mild to the skin (33). 

Like pyridine, pyridine homologues and derivatives are converted into amine oxides. a-Picoline oxide is prepared by oxidation with hydrogen peroxide in acetic acid in 83% yield [1188]. Under identical conditions, 2,5-dimethylpyridine oxide and nicotinamide oxide are obtained in 84% yield [160] and 73-82% yield [162], respectively. Pentachloropyridine is oxidized to its oxide by peroxyacetic or peroxytrifluoroacetic acid (equation 504) [755]. 

Ammonia was oxidized with hydrogen peroxide in the presence of TS-1 first to hydroxylamine and then, further to nitrogen oxides if the hydroxylamine was not trapped. When this reaction was run in the presence of a ketone, the oxime was selectively formed (Eqn. 21.8).33 Oximes were also produced by the oxidation of primary aliphatic amines with TS-1 or TS-2 and hydrogen peroxide at ambient temperature. Linear amines such as n-propyl amine (6) gave the oxime in 73% yield at 32% conversion over the TS-1 catalyst (Eqn. 21.9).3 The isopropyl amine (7) was oxidized with somewhat higher selectivity over the larger pore TS-2 catalyst (Eqn. 21.10).34 Primary aryl amines were oxidized to the symmetrical azoxybenzenes under these conditions (Eqn. 21.11). ... 

Tri-n-butylamine is converted to the amine oxide5 with hydrogen peroxide at 90°C, but the amine oxide was not detected (<1% by H-NMR) during the reaction of 1. The amine oxide was not an effective auxiliary for replacement of the amine. A representation of the general reaction is given in Scheme 1. 

Aminated starches have been further converted. For example, dimethyl-aminoethyl starch could be converted into glycosides by alcoholysis,2442 phosphorylated with sodium dihydrogenphosphate, and oxidized with hydrogen peroxide to carboxyl derivatives.520 Additional information on this subject can be found in Section VII. 2-Hydroxypropyltrimethylammonium chloride starch has been crosslinked with epichlorohydrin.2443 In contrast to animation, which requires basic solutions, phosphorylation occurs at pH 6.2444... 

F/60°C). Reacts violently with aldehydes, nitric acid, strong oxidizers, perchloric acid. Incompatible with strong acids, aliphatic amines. Reaction with hydrogen peroxide may form unstable peroxides. 

The importance of fully or partially hydrogenated isoxazolo[2,3-a]pyridines as intermediates in the synthesis of stereochemically complex molecules, particularly alkaloids, has led to a continued high level of interest in their preparation. The route of choice remains the 1,3-dipolar cycloaddition reaction between a tetrahydropyridine A-oxide, that is a nitrone, and a dipolarophile. A number of methods for the production of the nitrone for in situ reaction have been developed. They include the oxidation of the secondary amine, piperidine, with hydrogen peroxide in the presence of... 

The 3-pyridinols 74 can be prepared from furfural by reductive amination to furfurylamine and oxidation with hydrogen peroxide [135]. The respective 6-hydroxymethyl derivative 75 was prepared from 4-hydroxymethylfurfural by reductive amination followed by exposure to bromine in water/methanol to give a 2,5-dibromo derivative whose hydrolysis, ehmination of water, and cyclization gave 6-hydroxymethyl-3-pyridinol [136]. Similarly, glucosylated furfuryl amine derived from isomaltulose was converted to 76 (Fig. 13). 

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