Amine oxides from

CH—NHOH) to oxime (C=NOH) and ultimately to the nitroalkane (CH—NO2). Hydrogen peroxide generates amine oxides from tertiary cycloaUphatic... 

The assessors experienced an explosion while drying the oxide in ethyl ether. Rather drastic precautions are recommended in handling it [1], A preparation, allowed to stand for a week rather than the day specified, exploded during concentration [2], Amine oxides from the standard preparation are inclined to retain hydrogen peroxide of hydration unless it is destroyed during work-up. The perox-idate (or diperoxidate) of dimethylamine oxide would be expected to be far more dangerous than the oxide itself [3],... 

As the name suggests, the reverse Cope elimination reaction involves formation of a tertiary amine oxide from a hydroxylamine and olefin.17,18 For example, reaction of N-methylhydroxylamine (49) with 2,2-diphenyl-4-pentenal (50) in ethanol at room temperature gave amine oxide 51 in 51% yield, together with the expected nitrone 52. It has been suggested the mechanism of the reverse Cope reaction could be a radical chain reaction19,20 however, more recent studies have confirmed the mechanism is analogous to the concerted Cope elimination.17... 

A mild method for introducing double bonds is by pyrolysis of amine oxides (the Cope-Mamlock-Wolffenstein reaction92,93) it occurs at low temperatures (85-115°) and gives high yields and ds-elimination.94,95 When heated at 120° the amine oxide from optically pure Ar,Ar-dimethyl-(3-phenylbutyl)amine gives optically pure 3-phenyl-l-butene 96... 

Hydroperoxides in the presence of vanadium molybdenum, or titanium compounds give high yields of aliphatic tert. amine oxides from the corresponding amines and sulfones from thio-ethers or sulfoxides. 

N- Sulfonyloxaziridines Amine oxides from tert. amines R3N - R3N-.0... 

The first examples of epoxidation of olefins using oxaziridines have been described," by heating a two-fold excess of the alkene with 2-arenesulphonyl-3-aryloxaziridines (8) - (9). This particular reagent and method of aprotic oxygen transfer has been used before for the preparation of sulphoxides and amine oxides from sulphides and amines respectively, but olefins react considerably slower. 

An example along the above lines may be the new solvent-spun fiber Tencel, by Courtaulds, which recently was introduced. It is claimed to have an environmentally clean process, with virtually total recycling of the solvent." The manufacturing process is said to involve the dissolving of pulp in hot amine oxide, filtration of the solution, and then spinning into a bath containing a dilute solution of the solvent. The bath removes the amine oxide from the fibers, which are washed and dried, and the removed solvent is reclaimed for further use. The final fiber is said to have a different molecular structure from that of normal rayon, and a smooth surface and a round cross section. The fiber is claimed to be stronger than cotton and normal rayon in both the dry and the wet states. 

Amine oxide from free amines Water, pH 8 Petroleum ether Amine oxide Free amines 125... 

Amine oxide from other surfactants Dowex 50W-X4 strongly acidic cation exchange resin, acid form Surfactant mixture is dissolved in 50 50 Et0H/H20 and passed through the column, washing with 300 mL EtOH/H20. The amine oxide behaves as a cationic under acid conditions and remains on the column. The amine oxide is then eluted with 300 mL 1 M ethanolic HCl solution. 109... 

Cope Elimination- elimination of R2NOH from an amine oxide... 

Industrial specifications for aHphatic tertiary amine oxides generally requite an amine oxide content of 20—50%. These products may contain as much as 5% unreacted amine, although normally less than 2% is present. Residual hydrogen peroxide content is usually less than 0.5%. The most common solvent systems employed are water and aqueous isopropyl alcohol, although some amine oxides are available ia aoapolar solveats. Specificatioas for iadividual products are available from the producers. 

AHphatic amine oxides such as alkyl dimethyl amine oxides and aLkylbis(2-hydroxylethyl)amiae oxides range from practically nontoxic to slightly toxic (79). Reported LD qS range from 1.77 g/kg to 6.50 g/kg. The commercial concentrated products are primary skin and eye irritants. At concentrations of 2%, these products may be considered as nonirritating to the skin or eye. 

Ethylene oxide adds to the bis(2-hydtoxyethyl) teitiaiy amine in a random fashion where x y y = n y2. Ethoxylated amines, varying from strongly cationic to very weakly cationic in character, are available containing up to 50 mol of ethylene oxide/mol of amine. Ethyoxylated fatty amine quaternaries, cationic surfactants (both chloride from methyl chloride and acetate from acetic acid), ate also available. 

Eatty amine oxides are most frequendy prepared from alkyldimethylarnines by reaction with hydrogen peroxide. Aqueous 2-propanol is used as solvent to prepare amine oxides at concentrations of 50—60%. With water only as a solvent, amine oxides can only be prepared at lower concentrations because aqueous solutions are very viscous. Eatty amine oxides are weak cationic surfactants. 

In acidic media, amine oxides and anionic surfactants form precipitates the CMC is much greater than in neutral or alkaline media. Change in CMC parallels change from ionic to nonionic form. Amine oxides are stable in formulated detergent products and do not act as oxidizing agents. Composition and function of representative commercial amine oxides are given in Table 26. 

Two important pathways for catecholamine metaboHsm are 0-methylation by COMT, which is cytoplasmicaHy localized, and oxidative deamination by the mitochondrial localized enzyme MAO. There are large amounts of MAO in tissues such as the fiver and the heart which are responsible for the removal of most of the circulating monoamine, including some taken in from the diet. Tyramine is found in high concentrations in certain foods such as cheese, and in wine. Normally, this tyramine is deaminated in the fiver. However, if MAO is inhibited, the tyramine may then be converted into octopamine [104-14-37] which may indirecdy cause release of NE from nerve terminals to cause hypertensive crisis. Thus MAO, which is relatively nonspecific, plays an important role in the detoxification of pharmacologically active amines ingested from the diet. 

Tropolone has been made from 1,2-cycloheptanedione by bromination and reduction, and by reaction with A -bromosuccinimide from cyolo-heptanone by bromination, hydrolysis, and reduction from diethyl pimelate by acyloin condensation and bromination from cyclo-heptatriene by permanganate oxidation from 3,5-dihydroxybenzoic acid by a multistep synthesis from 2,3-dimethoxybenzoic acid by a multistep synthesis from tropone by chlorination and hydrolysis, by amination with hydrazine and hydrolysis, or by photooxidation followed by reduction with thiourea from cyclopentadiene and tetra-fluoroethylene and from cyclopentadiene and dichloroketene. - ... 

This formula was confirmed hy Haworth and Perkin s synthesis of a-flZZocryptopine from herherine, the first application of a process, of which examples have heen given already in the syntheses of cryptopine (p. 298) and protopine (p. 301) hy the same authors. Anhydrotetrahydromethyl-herherine (I cf. hase (a), p. 346) in dry chloroform was added to a solution of perhenzoic acid in ether cooled helow 5°. The amine oxide, C21H23O5N (II), separated as an oil, which after shaking with sodium hydroxide solution, solidified and was crystallised from water in slender prisms, m.p. 135°. It was dissolved in acetic acid, hydrochloric acid added, the mixture heated in boiling water for an hour and the hase precipitated hy addition of potassium hydroxide. The precipitate was dissolved in methyl alcohol, ether added, the alcohol washed out with water and the ethereal... 

In Robinson s now well-known suggestions, regarding the processes by which alkaloids may be produced in plants, two main reactions are used j the aldol condensation and the similar condensation of carbinol-amines, resulting from the combination of an aldehyde or ketone with ammonia or an amine, and containing the group. C(OH). N., with substances in which the group, CH. CO. is present. By these reactions it is possible to form the alkaloid skeleton, and the further necessary changes postulated include oxidations or reductions and elimination of water for the formation of an aromatic nucleus or of an ethylene derivative. 

H2/Pd-C. If hydrogenation is carried out in the presence of (B0C)20, the released amine is directly converted to the BOC derivative. The formation of A-methylated lysines during the hydrogenolysis of a Z group has been observed with MeOH/DMF as the solvent. Formaldehyde derived oxidatively from methanol is the source of the methyl carbon. ... 

The mechanism is supported by findings from the decomposition reaction of the amine oxides derived from threo- and cryt/zro-2-amino-3-phenylbutane. The t/zrco-amine oxide 6 yields -2-phenylbut-2-ene 7 with a selectivity of 400 1, and the cryt/zro-derivative 8 yields the Z-olefin 9 with a selectivity of 20 1 ... 

Certain amine oxides, especially those derived from six-membered heterocyclic amines e.g. N-methylpiperidine oxide, that cannot go through a planar, five-membered transition state, do not undergo the Cope elimination reaction. 

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