Hydroxylamines, hydrogenation

Nitrogen, phosphorus and arsenic form more than one hydride. Nitrogen forms several but of these only ammonia, NHj, hydrazine, N2H4 and hydrogen azide N3H (and the ammonia derivative hydroxylamine) will be considered. Phosphorus and arsenic form the hydrides diphosphane P2H4 and diarsane AS2H4 respectively, but both of these hydrides are very unstable. 

Hydroxylamine is derived from ammonia by replacing one hydrogen atom by a hydroxyl group. It is prepared by the electrolytic reduction of nitric acid, using a lead cathode ... 

Hydrazine, like hydroxylamine, may be considered as a derivative of ammonia, one hydrogen atom being replaced by an —NHj group. The structure is shown below (Figure 9.5). 

Like hydrogen peroxide the inorganic substances hydrazine (H2NNH2) and hydroxylamine (H2NOH) possess conformational mobility Wnte stmctural representations or build molecular models of two different staggered conformations of (a) hydrazine and (b) hydroxylamine... 

Compounds of the type R NH—OR are named (1) as alkoxyamino derivatives of compound R H, (2) as A, 0-substituted hydroxylamines, (3) as alkoxyamines (even if R is hydrogen), or (4) by the prefix aminooxy- when another substituent has priority for parent name. Examples of each type are... 

Lead dioxide Aluminum carbide, hydrogen peroxide, hydrogen sulfide, hydroxylamine, ni-troalkanes, nitrogen compounds, nonmetal halides, peroxoformic acid, phosphorus, phosphorus trichloride, potassium, sulfur, sulfur dioxide, sulfides, tungsten, zirconium... 

Rearrangement, Aliphatic amine oxides without an ahphatic hydrogen atom P to the nitrogen undergo Meisenheimer s rearrangement when heated to give trisubstituted hydroxylamines. 

Elimination. Ahphatic amine oxides having an ahphatic hydrogen P to the nitrogen form olefins and diaLkyl hydroxylamines when heated. This reaction is known as the Cope elimination (17)... 

YeUowing of wool can occur during dyeing, depending on pH, temperature and time, and chlorinated wools ate especially sensitive. Bleaching agents that can be added to the dyebath have been developed based on sodium bisulfite and hydroxylamine sulfate (108). Addition of hydrogen peroxide to the dyebath after exhaustion can also be effective. 

Allied-Signal Process. Cyclohexanone [108-94-1] is produced in 98% yield at 95% conversion by liquid-phase catal57tic hydrogenation of phenol. Hydroxylamine sulfate is produced in aqueous solution by the conventional Raschig process, wherein NO from the catalytic air oxidation of ammonia is absorbed in ammonium carbonate solution as ammonium nitrite (eq. 1). The latter is reduced with sulfur dioxide to hydroxylamine disulfonate (eq. 2), which is hydrolyzed to acidic hydroxylamine sulfate solution (eq. 3). 

Hydroxylamine sulfate is produced by direct hydrogen reduction of nitric oxide over platinum catalyst in the presence of sulfuric acid. Only 0.9 kg ammonium sulfate is produced per kilogram of caprolactam, but at the expense of hydrogen consumption (11). A concentrated nitric oxide stream is obtained by catalytic oxidation of ammonia with oxygen. Steam is used as a diluent in order to avoid operating within the explosive limits for the system. The oxidation is followed by condensation of the steam. The net reaction is... 

Dutch State Mines (Stamicarbon). Vapor-phase, catalytic hydrogenation of phenol to cyclohexanone over palladium on alumina, Hcensed by Stamicarbon, the engineering subsidiary of DSM, gives a 95% yield at high conversion plus an additional 3% by dehydrogenation of coproduct cyclohexanol over a copper catalyst. Cyclohexane oxidation, an alternative route to cyclohexanone, is used in the United States and in Asia by DSM. A cyclohexane vapor-cloud explosion occurred in 1975 at a co-owned DSM plant in Flixborough, UK (12) the plant was rebuilt but later closed. In addition to the conventional Raschig process for hydroxylamine, DSM has developed a hydroxylamine phosphate—oxime (HPO) process for cyclohexanone oxime no by-product ammonium sulfate is produced. Catalytic ammonia oxidation is followed by absorption of NO in a buffered aqueous phosphoric acid... 

The chemical consequences of /3-protonation are illustrated further by the ring-opening reactions of furans with methanolic hydrogen chloride and of (V-substituted pyrroles with hydroxylamine hydrochloride (Scheme 11) (82CC800). 

Isatin (190) is a compound with interesting chemistry. It can be iV-acetylated with acetic anhydride, iV-methylated via its sodium or potassium salt and O-methylated via its silver salt. Oxidation of isatins with hydrogen peroxide in methanolic sodium methoxide yields methyl anthranilates (81AG(E)882>. In moist air, O-methylisatin (191) forms methylisatoid (192). Isatin forms normal carbonyl derivatives (193) with ketonic reagents such as hydroxylamine and phenylhydrazine and the reactive 3-carbonyl group also undergoes aldol condensation with active methylene compounds. Isatin forms a complex derivative, isamic acid (194), with ammonia (76JCS(P1)2004). 

The treatment of 3-acylisoxazoles (438) with hydroxylamine hydrochloride gives furazan ketones (439). On the other hand, furazan ketones (439) rearrange to 3-acylisoxazoles (438) with a loss of hydroxylamine under the influence of a mineral acid. Thus, by refluxing phenacylphenylfurazan with concentrated alcoholic hydrogen chloride, 3-benzoyl-5-phenyl-isoxazole is formed similarly, phenyl(phenacylphenyl)furazan gives 3-benzoyl-3,5-diphenyl-isoxazole (62HC(17)1, p. 35). 

Controlled hydrogenation over Ni or the electrochemical reduction of o -nitrobenzo itriles produced 3-amino-2,l-benzisoxazoles either as the major product or by-product, depending in part on the reaction media and ratio of reactants (72BSF2365, 65CB1562). Reduction of o-nitrobenzonitrile gave either 3-amino-2,l-benzisoxazole or 2-aminobenzonitrile. The benzisoxazole is presumed to arise via an intermediate hydroxylamine. The electrochemical reduction of o-nitrobenzonitrile at acid pH produced the hydroxylamine as the primary product. Reduction at neutral pH gave the amino-2,1-benzisoxazole and the hydroxylamine (72BSF2365). 

These reactors for hquids and liquids plus gases employ small particles in the range of 0.05 to 1.0 mm (0.0020 to 0.039 in), the minimum size hmited by filterability. Small diameters are used to provide as large an interface as possible since the internal surface of porous pellets is poorly accessible to the hquid phase. Solids concentrations up to 10 percent by volume can be handled. In hydrogenation of oils with Ni catalyst, however, the sohds content is about 0.5 percent, and in the manufacture of hydroxylamine phosphate with Pd-C it is 0.05 percent. Fischer-Tropsch slurry reac tors have been tested with concentrations of 10 to 950 g catalyst/L (0.624 to 59.3 IbiTi/fF) (Satterfield and Huff, Chem. Eng. Sci., 35, 195 [1980]). 

Nareeine eontains three methoxyl and two methyl-groups attached to nitrogen, reaets with phenylhydrazine or hydroxylamine, furnishing phenylhydrazone or oxime anhydrides and esterifies with aleohols in presence of hydrogen chloride. From a study of these reactions, and in... 

Forsyth et al. found that gelsemicine contains three active hydrogen atoms (Zerewitinov determination), yields a non-basic, monobenzoyl derivative, m.p. 232°, and behaves as a secondary base giving JV-methyl-gelsemicine hydriodide, m.p. 227°, on treatment with methyl iodide. It does not react with either hydroxylamine or 2 4-dinitrophenylhydrazine. On hydrogenation in dry acetic acid in presence of Adams s platinic oxide catalyst it absorbs three molecules of hydrogen. 

This reaction provides a wide variety of products since decomposition of the deuterated alkylborane intermediate (164) can be achieved with hydrogen peroxide to yield labeled alcohols (165), with hydroxylamine-O-sulfonic acid leading to deuterated amines (166), as well as with boiling propionic acid or propionic acid-OD, to form mono- (167) or dideuterio (168) hydrocarbons, respectively. Furthermore, if a monodeuterium label at the sterically more accessible position (170) is sufficient, the use of expensive metal deute-... 

Nucleophiles like alcohols [2, S], hydrogen sulfide [2], thiols [2,10], ammonia, amines, hydrazines, hydroxylamines [2 11, 12, 13, 14, 75], azides [2], other pseudohalides [2], phosphonates [2,16,17,18,19, 20], and phosphanes [2,19] add rapidly across the CO or CN double bond to yield stable adducts The phosphonate adduets undergo a subsequent aleohol—lester rearrangement [19, 20] (equation 2)... 

---