Nitro compounds Dimethyldioxirane

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... 

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. 

Aliphatic and aromatic primary amines are rapidly and efficiently oxidized to nitro compounds by dimethyldioxirane.111 Dimethyldioxirane is prepared by reaction of OXONE (DuPont trademark)-2KHS05-KHS04-K2S04 with buffered aqueous acetone.112... 

In a typical reaction, w-butylamine (0.052 g, 0.7 mmol) in 5 ml of acetone is treated with 95 ml of dimethyldioxirane in acetone solution (0.05 M). The solution is kept at room temperature for 30 min with the exclusion of light (Eq. 2.53). Aromatic amines are converted into nitro compounds by oxidation using OXONE itself.113... 

The standard reaction sequence for transformation of a carboxylic acid into a nitro group is lengthy. Eaton has shortened this conversion via oxidation of isocyanates to nitro compounds with dimethyldioxirane in wet acetone (Eq. 2.71).140... 

Sodium perborate in acetic acid converts oximes into nitro compounds thus acetophenone oxime yields 52% of PhCHMeN02403. Nitroalkanes and nitroarenes are obtained from isocyanates and dimethyldioxirane (equation 122)404. 

Primary, secondary and tertiary aliphatic amines are efficiently converted to nitro compounds in 80-90 % yield with dimethyldioxirane, a reagent prepared from the reaction of oxone (2KHSO5-KHSO4-K2SO4) with buffered acetone. Dimethyldioxirane (DMDO) has been used for the synthesis of 1,3,5,7-tetranitroadamantane (71) from the corresponding tetraamine as the tetrahydrochloride salt (70) and is an improvement over the initial synthesis using permanganate anion (Table 1.7). ° Oxone is able to directly convert some aromatic amines into nitro compounds. 

Tertiary alkyl primary amines can be oxidized to nitro compounds in excellent yields with KMn04.39S This type of nitro compound is not easily prepared in other ways. All classes of primary amine (including primary, secondary, and tertiary alkyl as well as aryl) are oxidized to nitro compounds in high yields with dimethyldioxirane.399 Other reagents that oxidize various types of primary amines to nitro compounds are dry ozone,4,111 various peracids,401 including peracetic and peroxytrifluoroacetic acids, f-butyl hydroperoxide in the presence of certain molybdenum and vanadium compounds,402 F7-H20-MeCN,41123 and sodium perborate.403... 

Dimethyldioxirane in wet acetone oxidizes isocyanates to nitro compounds (RNCO —> RN02).404 Oximes can be oxidized to nitro compounds with peroxytrifluoroacetic acid, among other ways.398 Primary and secondary alkyl azides have been converted to nitro compounds by treatment with Ph3P followed by ozone.405 Aromatic nitroso compounds are easily oxidized to nitro compounds by many oxidizing agents.4416 OS III, 334 V, 367, 845 VI, 803. 

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

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

Reactions which formally involve the oxidation of azides have been reviewed by Boyer. Other oxidations with useful synthetic applications include two which start from nitrogen ylides. Sulfimides (50) derived from electron-deficient aromatic and heterocyclic amines are oxidized to the corresponding nitroso compounds by MCPBA. > This is a very useful method of preparation of some otherwise inaccessible nitroso compounds such as 2-nitrosopyridine and 1-nitrosoisoquinoline. They can be further oxidized, for example by ozone, to the nitro compounds. Phosphimides (51) are oxidized directly by ozone to the nitro compounds, although the nitroso compounds are intermediates. Isocyanates can also be oxidized to the corresponding nitro compounds, by dimethyldioxirane (1). ... 

Dimethyldioxirane, together with acetone, is removed from the reaction vessel by distillation. The yellow 0.1-0.2 M solution can be used as an oxidizing agent, e.g. for the epoxidation of olefins [19], for the oxidation of enolates to a-hydroxycarbonyl compounds and for the oxidation of primary amines into nitro compounds ... 

Oxidation of primary amines RNH2 with dimethyldioxirane (235), generated from acetone and oxone , 2KHS05-KHS04-K2S02, affords the corresponding nitro compounds Fluorine reacts with wet acetonitrile to produce an oxidizing... 

Aliphatic amines are more difficult to oxidise than aromatics. Peracetic acid in a solvent will lead to nitro-compounds [184], but more recently it has been shown that dimethyldioxirane performs this oxidation very well, either pre-formed in acetone solution [185] or prepared in situ (at least for... 

Anilines containing a carboxylic or alcoholic functionality are oxidized to nitro compounds by oxone in 20-50% aqueous acetone at 18 C in 73-84% yields [46]. When the reactions are performed in the absence of acetone, lower yields are obtained, suggesting the generation of dimethyldioxirane, which competes with oxone. 

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