Amine oxides anilines

Sultones react easily with amines and anilines <1989PHA294, 1989EJC259, 1987LA481> 1,2-oxathiin 2,2-dioxide derivatives 104 condensed to give the corresponding sultams 105 but 1,2-oxathiane 2,2-oxides 16 were cleaved by aniline or benzoylhydrazine derivatives to provide the corresponding sulfonic acids 106 (Scheme 25) <1993AFF256>. 

However, the production of the />-phenylenediamine [106-50-3] intermediate is more complex, because it involves the diazotization and coupling of aniline [65-53-3]. Aniline reacts with nitrogen oxides, produced via the oxidation of ammonia, to form 1,3-diphenyltriazene [136-35-6] in the process used by Du Pont (208,209) (see Amines, aromatic-aniline and its derivatives). In the Akzo process a metal nitrite salt and acid in water is used (210). The triazene rearranges in the presence of acid and an excess of aniline to form predominately the p-aminoazobenzene [60-09-3] and a small amount of the ortho isomer, 0-aminoazobenzene [2835-58-7]. The mixture of isomers is catalytically reduced to the respective diamines, and they are then separated from the aniline, which is recycled (208,209). The 0-phenylenedi amine [95-54-5] is used in the manufacture of herbicides (see Amines, aromatic-phenylenediamines). 

Aniline may be made (I) hy Ihe reduction, with iron or tin in HOI, of nitrobenzene, and (2) by the amination of chlorobenzene by healing with ammonia to a high temperature corresponding to a pressure of over 200 atmospheres in the presence of a catalyst (a mixture of cuprous chloride and oxide). Aniline is the end-point of reduction of most mono-nitrogen substituted benzene nuclei, as nitrosobenzene, beta-phenylhydroxylamine. azoxybenzene, azobenzene, hydrazobenzene. Aniline is detected by the violet coloration produced by a small amount of sodium hypochlorite. 

Similar to M11O2, BaMn04 is able to oxidize functional groups other than alcohols, including primary amines,76b anilines,76b,83a imidazolines,90 saturated hemiacetals91 and thiols.84a,88b... 

Ogata and Tabushi studied the kinetics of oxidation of some N,N-dimethyl-anilines in aqueous solutions of pH 1-12 at 25 °C (some runs were performed at other temperatures in the range 15-30 °C). The product of oxidation is an amine oxide, viz. 

Oxidation of tertiary amines with N-chloronylon 6,6 has also been investigated in several solvents Thus, N-chloronylon has been found to oxidize N J -dimethyl-aniline at room temperature to N-methylaniline in 15—50% yield, depending on the solvent used. The oxidation of NJM-dimethylbenzylamine gives benzddehyde in 15-30% yield and a small amount of N-methylbenzylamine. A comparison of these oxidations with those using the low molecular wei t analoges, e. g. N-chlorosuccin-imide, indicates that in both cases the reaction paths are similar. However, the poor yields observed in these oxidations of amines make these polymeric oxidizing agents unsuitable for amine oxidations. 

Sayari et al. [172,174] found that like their Ti containing analogs, V-HMS and V-MCM-41 are efficient catalysts for the hydroxylation of bulky aromatic molecules such as naphthol and 2,6 DTBP. Gontier et al. [186,237] found that V-HMS has no activity in the oxidation of aromatic amines in the presence of H2O2. However, it oxidizes aniline selectively into nitrobenzene when TBHP and acetonitrile are used as oxidant and solvent, respectively. Notice that Ti-HMS is active even in the presence of H2O2 and gives a different product distribution, particularly azoxybenzene [237], Das et al. [193] also reported that Sn-MCM-41 is effective in the liquid phase hydroxylation of phenol and naphthol. 

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