Amines manganese dioxide

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... 

At the end of the reaction time there was no unreacted amine as shown by the following test A 10-ml. aliquot was filtered through Supercel to remove the manganese dioxide, and the filtrate was added to a mixture of 25 ml. of benzene and 25 ml. of water. Extraction of the benzene layer with 10% hydrochloric acid, followed by the addition of sodium hydroxide, gave no oil layer or characteristic odor of the free amine. 

Zhang H, C-H Huang (2005) Oxidative transformation of fluoroquinolone antibacterial agents and structu-iraloly related amines by manganese dioxide. Environ Sci Technol 39 4474-4483. 

Maleic anhydride Manganese dioxide Alkali metals, amines, KOH, NaOH, pyridine Aluminum, hydrogen sulfide, oxidants, potassium azide, hydrogen peroxide, peroxosulfuric acid, sodium peroxide... 

Laha, S. and Luthy, R.G. Oxidation of aniline and other primary aromatic amines by manganese dioxide. Environ. Sci. TechnoL, 24(3) 363-373, 1990. 

The nitrosodisulfonate salts, particularly the dipotassium salt called Fremy s salt, are useful reagents for the selective oxidation of phenols and aromatic amines to quinones (the Teuber reaction). - Dipotassium nitrosodisulfonate has been prepared by the oxidation of a hydroxylaminedisulfonate salt with potassium permanganate, " with lead dioxide, or by electrolysis. This salt is also available commercially. The present procedure illustrates the electrolytic oxidation to form an alkaline aqueous solution of the relatively soluble disodium nitrosodisulfonate. This procedure avoids a preliminary filtration which is required to remove manganese dioxide formed when potassium permanganate is used as the oxidant. " ... 

Treatment of isopropyl 6-hydroxy-4-methoxymethyl-/3-carboline-3-carboxylate 189 with a primary amine in the presence of an excess of manganese dioxide produces the oxazolo[4,5-g]-/3-carboline 190 in moderate yield (Equation 125) <1998H(48)31>. The efficiency of the reaction is limited by the formation of by-products. 

Among the oxidative procedures for preparing azo compounds are oxidation of aromatic amines with activated manganese dioxide oxidation of fluorinated aromatic amines with sodium hypochlorite oxidation of aromatic amines with peracids in the presence of cupric ions oxidation of hindered aliphatic amines with iodine pentafluoride oxidation of both aromatic and aliphatic hydrazine derivatives with a variety of reagents such as hydrogen peroxide, halogens or hypochlorites, mercuric oxide, A-bromosuccinimide, nitric acid, and oxides of nitrogen. 

Other oxidative methods have recently been reported whereby amines yield enamines either as intermediates [130] or as isolatable chloranil [131], 2,3-dichloronaphtha-l,4-quinone [131], or 2,5-dichloro-3,6-dimethoxybenzo-quinone [132, 133] adducts. Benzoyl peroxide [131] and active manganese dioxide [134] have been reported as effective oxidizing agents in the reactions above. (See Eqs. 49, 50.)... 

General Procedure for Oxidation of Aromatic Amines with Active Manganese Dioxide [69b]... 

Oxidation of the salt (125) with active manganese dioxide gives a high yield of thiophene-2-carbaldehyde (67G397). Amines, both primary and secondary, readily cleave the ring with expulsion of hydrogen sulfide and generation of the iminium species (128) in up to 90%... 

Sulfonamides are usually oxidized to sulfonamides tns(tnfluoromethane-sulfeny 1) and bis(tnfluoiomethanesulfenyl)amine are converted to the correspond ing sulfonamides by sodium hypochlorite at 20 °C lor 3 h in 61 and 92% yield, respectively [111] Oxidation of pentafluorobenzenesulfenamide by manganese dioxide yields a sulfinamide intermediate that can be trapped [112] (equauon 102)... 

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