Nitro To amine

In general, peroxomonosulfates have fewer uses in organic chemistry than peroxodisulfates. However, the triple salt is used for oxidizing ketones (qv) to dioxiranes (7) (71,72), which in turn are useful oxidants in organic chemistry. Acetone in water is oxidized by triple salt to dimethyldioxirane, which in turn oxidizes alkenes to epoxides, polycycHc aromatic hydrocarbons to oxides and diones, amines to nitro compounds, sulfides to sulfoxides, phosphines to phosphine oxides, and alkanes to alcohols or carbonyl compounds. 

Obsolete uses of urea peroxohydrate, as a convenient source of aqueous hydrogen peroxide, include the chemical deburring of metals, as a topical disinfectant and mouth wash, and as a hairdresser s bleach. In the 1990s the compound has been studied as a laboratory oxidant in organic chemistry (99,100). It effects epoxidation, the Baeyer-Villiger reaction, oxidation of aromatic amines to nitro compounds, and the conversion of sodium and nitrogen compounds to S—O and N—O compounds. 

Nitroso compounds are formed selectively via the oxidation of a primary aromatic amine with Caro s acid [7722-86-3] (H2SO ) or Oxone (Du Pont trademark) monopersulfate compound (2KHSO KHSO K SO aniline black [13007-86-8] is obtained if the oxidation is carried out with salts of persulfiiric acid (31). Oxidation of aromatic amines to nitro compounds can be carried out with peroxytrifluoroacetic acid (32). Hydrogen peroxide with acetonitrile converts aniline in a methanol solution to azoxybenzene [495-48-7] (33), perborate in glacial acetic acid yields azobenzene [103-33-3] (34). 

Bicychc pyrazinones foimd in several natural products were synthesized via Michael addition of heterocyclic amines to nitro olefin followed by reduction/cyclization of the nitro group of the adduct [20] (Scheme 5). Further elaboration of the C-6 methoxycarbonyl group in pyrazinone to the n-propyl guanidine group could result in the synthesis of indoloperamine. 

All classes of primary amine (including primary, secondary, and tertiary alkyl as well as aryl) are oxidized to nitro compounds in high yields with dimethyl dioxirane." Other reagents that oxidize various types of primary amines to nitro compounds are dry ozone, various peroxyacids," MeRe03/H202,"" Oxone ," ° tcrt-butyl hydroperoxide in the presence of certain molybdenum and vanadium compounds, and sodium perborate." ... 

In the synthesis of N heterocycles, this technique also overcomes competitive retro Michael addition that lowers the yield of 1,4-adduct in the Michael addition of amines to nitro olefins. Thus, a toluene solution of nitro olefin 159 was treated with allylamine 160, EtgN, and TMSCI under nitrogen at ambient tern-... 

Aromatic amines, Sulfuric acid Nielsen, A. T. etal., J. Org. Chem., 1980, 45, 2341-2347 The acid, prepared from 90-98% hydrogen peroxide and oleum or 100% sulfuric acid, is one of the most powerful known oxidants and its use for oxidising aromatic amines to nitro compounds has been studied. Some mono- di- and tri-amines are destroyed exothermically with violent fume-off. Precautions for use are detailed. 

A recent method reported for the oxidation of primary aliphatic amines to nitro compounds uses fert-butylhydroperoxide (TBHP) and catalytic zirconium tetra-fert-butoxide in presence of molecular sieves. 

RNH2 —> RN02.3 Dimethyldioxirane oxidizes aliphatic or aromatic amines to nitro compounds in 85-97% yield, probably via the intermediates shown in equation (I). 

Methoxy-2,2,6,6-tetramethyl-1 -oxopiperidinium chloride, 183 Pyridinium chlorochromate-Benzotria-zole, 262 of amines to nitro compounds Dimethyldioxirane, 120 other nitrogen compounds /-Butyl hydroperoxide-Dichlorotris-(triphenylphosphine)ruthe-nium(II), 54 Di-/-butylimoxyl, 94 Potassium ruthenate, 259 Ruthenium tetroxide, 268 of aromatic side chains Trimethylsilyl chlorochromate, 327 of diols... 

Oxidation of aromatic primary amines to nitro compounds is not generally required. However, in the case of deactivated molecules or in order to obtain specific substitution patterns, this transformation may be useful. The reaction can be performed in the presence of peracids.322... 

Dimethyldioxirane oxidizes primary amines to nitro compounds either preformed349 in acetone or in situ.350... 

The oxidation of amines to nitro compounds has preparative value when the amines are more readily available than the corresponding nitro compounds, as in the case of the aminopyridines and aminoquinolines (cf. method 439). Oxidation is accomplished with hydrogen peroxide, as shown in the formation of 2-nitropyridine (75%). ... 

Dioxiranes, prepared from acetone and other aliphatic ketones by treatment with Oxone, can accomplish oxidations that are usually not achieved by Oxone itself [210, 211], Dioxiranes can be isolated by vacuum codistillation with the respective ketones [210], or else, they may be formed in situ and applied in the same reaction vessel [210, 211]. Examples of the applications of dioxiranes are epoxidations 210] and the oxidation of primary amines to nitro compounds [211], of tertiary amines to amine oxides [210], and of sulfides to sulfoxides [210] (equation 12). 

Oxidations with m-chloroperoxybenzoic acid are carried out in solutions in hexane, dichloromethane, chloroform, methanol, or tetrahydro-furan at temperatures ranging from -78 to 40 C. The applications of m-chloroperoxybenzoic acid are epoxidation [287, 314, 315, 316] the Baeyer-Villiger reaction [286, 315, 317, 378] and the oxidation of primary amines to nitro compounds [379], of tertiary amines to amine oxides [320], of sulfides to sulfoxides [327, 322, 323, 324], and of selenides to selenones [325]. Secondary alcohols are oxidized to ketones in the presence of hydrogen chloride [326], and acetals are oxidized to esters with boron trifluoride etherate as a catalyst [327]. The addition of potassium fluoride to reaction mixtures facilitates product isolation, because both m-chloroben-zoic acid and the unreacted m-chloroperoxybenzoic acid are precipitated... 

Secondary alcohols have been oxidized to ketones with excess ferf-butylhydroperoxide in up to 93-99% yields using a zirconium catalyst.250 Zirconium catalysts have also been used with ferf-butylhydroperoxide in the oxidation of aromatic amines to nitro compounds and of phenols to quinones. Allylic oxidation of steroids in 75-84% yields has been performed with ferf-butylhydroperoxide and cop-... 

Other oxidations achieved with this reagent include sulfides to sulfones - and amines to nitro compounds." Actually, polyfunctional compounds show useful chemoselectivities. a-Nitroacetic esters are quantitatively prepared from glycine esters. 

Peroxytrifluoroacetic acid is considered the reagent of choice for the direct oxidation of weakly basic primary aromatic amines to nitro compounds. ... 

Dioxiranes. These organic peroxygen compounds are relative newcomers to synthetic chemistry, but in the last ten years it has been shown that they are among the most powerful and versatile non-metal oxidants available to the organic chemist, with the ability to oxidise amines to nitro-compounds, to epoxidise very unreactive double bonds, and to hydroxy late alkanes and aromatic side-chains [26]. 

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