Ozone primary amines

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." ... 

Preservatives, pharmaceutical preparations, 623 PRESS technique, NIR spectrophotometry, 624 Primary amines, dioxirane oxidation, 1151 Primary ozonides (POZ), 716, 717 dialkyl peroxide formation, 706 IR spectroscopy, 718, 719-20 microwave spectroscopy, 721 molecular model, 750 NMR spectroscopy, 709, 723-4 octaUn ozonation, 165 ozone water disinfection, 606 7r-complexes with ozone, 732... 

The popularity of the Nef reaction is due in part to the ready availability of nitro compounds. Primary and secondary halides react with sodium nitrite in dimeAyl sulfoxide (DMSO) or dimethylform-amide (DMF) to give useful yields of nitro compounds. Primary amines can be oxidized to nitro compounds with potassium permanganate, m-chloroperbenzoic acitP or ozone. Chlorination of oximes with hypochlorous acid and reduction with magnesium, zinc or hydrogen/lpalladium gives secondary nitro compounds. Stabilized carbanions can be nitrated by treauitent with a nitrate ester, and enol acetates are nitrated by acetyl nitrate to give nitro ketones. ... 

Dry ozonization is also an efficient proc ure for oxidation of aliphatic primary amines into nitro groups, with yields of about 70%. Arylamines are also oxidized to nitro aronutics, albeit witii low yields. Ozone on silica gel has also been shown to oxidize arenes in some cases. ... 

Nickel peroxide, an undefined black oxide of nickel, is prepared from nickel sulfate hexahydrate by oxidation in alkaline medium with an ozone-oxygen mixture [929] or with sodium hypochlorite [930, 931, 932, 933]. Its main applications are the oxidation of aromatic side chains to carboxyls [933], of allylic and benzylic alcohols to aldehydes in organic solvents [929, 932] or to acids in aqueous alkaline solutions [929, 930, 932], and of aldehydes to acids [934, the conversion of aldehyde or ketone hydrazones into diazo compounds [935] the dehydrogenative coupling of ketones in the a positions with respect to carbonyl groups [931] and the dehydrogenation of primary amines to nitriles or azo compounds [936]. 

In all these cases the methylglyoxal or the dimethylglyoxal has been formed from a structure in which the - and -carbon atoms are linked by a single carbon bond. It is assumed that the pyrroles can react with ozone according to polar valence structures. According to the reaction scheme outlined below, which contains various unproved assumptions, the polar form of the pyrrole homolog will react with molecules of ozone, while on decomposition of the reaction product, the nitrogen will be split off as ammonia (or as a primary amine). 

The probable reaction course to the nitroalkane (XI), after the formation of the amine-ozone adduct (Reaction 1), is shown by Reactions 7 to 9 and summed up in Reaction 10. A primary amine oxide would not be expected to be stable and should rearrange to the hydroxylamine (IX, Reaction 7). A similar set of reactions (Reaction 8) should result in the nitrosoalkane (X), which should then be converted to the nitroalkane (XI) as shown in Reaction 9. Evidence for this series of reactions was the observation of the blue color of the nitrosoalkane (X) throughout the ozonation and the demonstration, in separate experiments, that the hydroxylamine (IX) reacts with two mole equivalents of ozone and the nitrosoalkane (X) with one mole equivalent of ozone, each to give the nitroalkane (XI). 

Ozonation of Heteroatoms. Phosphines are converted to phosphine oxides and phosphites to phosphates by ozone. These reactions are quite general and a wide range of sub-stitutents can be tolerated. Phosphine oxides also can be produced by the ozonation of alkylidenetriphenylphosphoranes or of thio- or selenophosphoranes. Organic sulfides are converted to sulfoxides and sulfones by ozonation. Tertiary amines are converted to amine oxides, while nitro compounds can be produced in modest yields by ozonation of primary amines. This preparation of nitroalkanes compares well with alternate approaches using peroxides, peroxy acids, permanganate, or Monoperoxysulfuric Acid, but ozonation on silica gel has proven to be superior (see Ozone-Silica Get). Selenides are converted to selenoxides by ozone and this reaction is often used to achieve overall production of unsaturated carbonyl compounds. An example is shown in eq 25. ... 

Oxidation of 3,4-dihydropyridin-2-ones (229) (which are easily made by heating primary amines with cycloalkanone propionic esters), and the eneamide (231), with ozone or m-chloroperoxybenzoic acid has led to medium- and macro-cyclic ketoimides (230) and A -acetylketolactams (232) respectively (Scheme 105). ... 

Primary amino groups are oxidized stepwise by ozone to hydroxylamine, nitroso, and nitro (54,58) tertiary amines are oxidized to amine oxides. 

Nickel peroxide is a solid, insoluble oxidant prepared by reaction of nickel (II) salts with hypochlorite or ozone in aqueous alkaline solution. This reagent when used in nonpolar medium is similar to, but more reactive than, activated manganese dioxide in selectively oxidizing allylic or acetylenic alcohols. It also reacts rapidly with amines, phenols, hydrazones and sulfides so that selective oxidation of allylic alcohols in the presence of these functionalities may not be possible. In basic media the oxidizing power of nickel peroxide is increased and saturated primary alcohols can be oxidized directly to carboxylic acids. In the presence of ammonia at —20°, primary allylic alcohols give amides while at elevated temperatures nitriles are formed. At elevated temperatures efficient cleavage of a-glycols, a-ketols... 

Cyanoacetaldehyde, freshly prepared by the ozonization of allyl cyanide or ( )-l,4-dicyanobut-2-ene, reacts with primary aromatic amines to give the fi-cyanoenamines 279307. 

While primary aliphatic amines are converted to nitro compounds on reaction with ozone these reactions are accompanied by numerous by-products.Such side-reactions are largely suppressed by first dissolving the amine onto silica gel followed by passing a stream of 3 % ozone in oxygen through the solid at -78 °C under anhydrous conditions, where yields of between 60 and 70 % are reported. This route has been used to synthesize the energetic cyclopropane (65) from the diamine (64) (Table 1.7). ... 

The cure speed and adhesion of an anaerobic sealant can be increased by treatment of the surface with a solution of a primer or activator. Early anaerobic thread lockers were strongly affected by part cleanhness, and degreasing the parts with a chlorinated solvent improved performance dramatically. The condensation product of an aldehyde and a primary or secondary amine, a sulfur-containing radical accelerator, or a compound of an oxidizable transition metal were some of the materials used to activate the anaerobic cure [182] - [184]. Due to the ozone-depleting potential of chlorinated solvents, acetone, alcohols, or hydrocarbon solvents are generally used at present. 

Treatment of oxazole with one equivalent of ozone cleaves the C-C bond and yields Ai-formylformatnide (4) (eq 5). Subsequent addition of primary or secondary amines gives high yields of for-mamides (eq 6). Formylation of alcohols is substantially slower. 

---