Sulfation reactions hydroxylamines

Diazonium compounds decompose when copper powder and alcohol are added to their aqueous solutions, biphenyl derivatives being formed,797 but this reaction is of importance only in special cases. A variant which gives up to 84% of the biaryl is to treat the diazonium salt with a solution of tetraaminocopper sulfate and hydroxylamine.798... 

Other Applications. Hydroxylamine-O-sulfonic acid [2950-43-8] h.2is many applications in the area of organic synthesis. The use of this material for organic transformations has been thoroughly reviewed (125,126). The preparation of the acid involves the reaction of hydroxjlamine [5470-11-1] with oleum in the presence of ammonium sulfate [7783-20-2] (127). The acid has found appHcation in the preparation of hydra2ines from amines, aUphatic amines from activated methylene compounds, aromatic amines from activated aromatic compounds, amides from esters, and oximes. It is also an important reagent in reductive deamination and specialty nitrile production. 

Concentrations are controlled to yield a molten oxime product layer and a saturated (ca 40 wt %) ammonium sulfate solution ca 125% (theoretical) ammonium sulfate or 2.9 kg/kg caprolactam is produced as a result of side reactions in the hydroxylamine synthesis. 

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... 

Hydroxylamine can be prepared by a variety of reactions involving the reduction of nitrites, nitric acid or NO, or by the acid hydrolysis of nitroalkanes. In the conventional Raschig synthesis, an aqueous solution of NH4NO2 is reduced with HS04 /S02 at 0° to give the hydroxylamido-A ,A -disulfate anion which is then hydrolysed stepwise to hydroxylammonium sulfate ... 

A mixture of 150 grams of 1-(3, 4 -dimethoxyphenyl)-2-propanone and 70 grams of hydroxylamine hydrochloride in 125 cc of water is stirred while a solution of 51.3 grams of sodium carbonate in 150 cc of water is added over the course of 15 minutes, and while maintaining the reaction mixture at 30°-40°C. The reaction mixture is stirred for an additional two and one-half hour period at room temperature, and is then diluted with an equal volume of water and extracted three times with 300 cc portions of ether. The combined ether extracts are washed with water, dried over anhydrous magnesium sulfate, and the... 

N sodium hydroxide solution (5 ml) is added to a stirred suspension of S-methyllsothiosemi-carbazide hydroiodide (2.33 g) and hydroxylamine hydrochloride (0.70 g) In water (6 ml) and stirred for 48 hours. The solution is evaporated In vacuo to provide 1 -amino-3-hydroxy-guanidine. One-third of the residue is dissolved in 16 ml of ethanol and 2,6-dichlorobenzalde-hyde (0.6 g) Is added to this solution. The reaction mixture is then stirred for 48 hours. The solution is then evaporated in vacuo and the residue dissolved in ether (30 ml) and in hydrochloric acid (30 ml). The aqueous phase is rendered alkaline with 2 N sodium carbonate solution and extracted with ether. The ether layer is dried with sodium sulfate and evaporated. 

One molecular equivalent of 4-methylhexanone-2 is reacted with slightly more than one molecular equivalent of hydroxylamine. Desirably, the hydroxylamine is prepared in the presence of the 4-methylhexanone-2 by reacting the hydrochloride or sulfate or other salt of the hydroxylamine with a suitable base, such as sodium carbonate or sodium hydroxide. Desirably, the reaction mixture is agitated for a few hours to insure the conversion of the 4-methYlhexanone-2 to 4-methylhexanone-2 oxime. 

The base was being prepared by distilling a mixture of hydroxylamine hydrochloride and sodium hydroxide in methanol under reduced pressure, and a violent explosion occurred towards the end of distillation [1], probably owing to an increase in pressure above 53 mbar. It explodes when heated under atmospheric pressure [2], Traces of hydroxylamine remaining after reaction with acetonitrile to form acetamide oxime caused an explosion during evaporation of solvent. Traces can be removed by treatment with diacetyl monoxime and ammoniacal nickel sulfate, forming nickel dimethylglyoxime [3], An account of an extremely violent explosion towards the end of vacuum distillation had been published previously [4], Anhydrous hydroxylamine is usually stored at 10°C to prevent internal oxidation-reduction reactions which occur at ambient temperature [5], See other REDOX REACTIONS... 

The reaction of 2-chloro-4,5-dihydroimidazole 347 with hydroxylamine-O-sulfonic acid gives 2-hydroxylamino-4,5-dihydroimidazolium-O-sulfonate 348, which reacts with aldehydes and cyclic ketones to give the imidazo[l,2-f] fused 4,5-dihydro-l,2,4-oxadiazoles 350 (Scheme 58). Mechanistically, the reaction may be explained by the reaction of an imidazoline NH with the carbonyl followed by intramolecular electrophilic amination of the anionic oxygen present in the resultant intermediate 349 and elimination of the sulfate group <2003JOC4791>. 

The acid, protonating the hydroxylamine, prevents the reverse reaction and thus causes rapid and complete hydrolysis distillation of the final solution then drives off the aldehyde or ketone, and the hydroxylamine sulfate remains behind. This method must be used with care, however, as the acid may cause a Beckmann rearrangement to occur. 

Cupric sulfate exerts an effect on the silver chloride-hydroxylamine reaction similar in kind to that which it exerts on the hydrazine reaction, but in a smaller degree. If sufficient cupric sulfate is added to the hydroxylamine solution, the character of the reduction of silver chloride shifts towards that shown by the hydrazine reaction, e.g., the effect of gelatin becomes less pronounced, a minimum rate at a small gelatin addition is not obtained, and significant amounts of colloidal silver appear in the solution. 

German workers have also isolated a novel spirocyclic 4(5/7)-oxazolone 96 in high yield by reaction of 95 with hydroxylamine sulfate (Scheme 6.25). This was part of an investigation of the synthesis and reactions of 95. 

This reaction yields HA in an anhydrous medium CH3 N02 +H2 S04 =HOS02 CCH NOH(I) (I)+2H20=H2S04+HC00H+NH20H or H2S04 + CO+NH2 OH (Ref 1), Hydroxylamine sulfate is highly toxic. Its uses are similar to those for the acid sulfate... 

To a solution of sodium acetate in acetic acid was added hydroxylamine hydrochloride, and methanol was added until solution resulted. This solution was added to a solution of 2-hydroxymethylene-4,4,17a-trimethyl-androsta-2,5-dien-17p-ol-3-one in absolute methanol, and the combined solution was refluxed for 40 min on a steam bath. The reaction mixture was concentrated, the residue extracted with ethyl acetate, and the ethyl acetate extracts were washed with ethyl acetate, and the ethyl acetate extracts were washed with 5% hydrochloric acid, dried over anhydrous sodium sulfate and concentrated whereupon there separated solid material. 

A 90 x 6 cm column was packed with 2 kg of granular Amberlite IRA-410 resin in the chloride form (a vinylpyridine/divinylbenzene copolymer quaternized with dimethyl sulfate and converted to chloride) and washed with 3 kg of a 10% aqueous solution of sodium cyanate. This changed the resin from the chloride to the cyanate form. Sodium chloride and excess sodium cyanate were then washed from the column with distilled water until the effluent failed to give a white precipitate with silver nitrate. The reaction of equation (2) was conducted by elutriating the column with a solution of 105 grams (1.5 mols) of hydroxylamine hydrochloride in 400 ml water at about 15°C. 

To a solution of isopropyl ester of 6-formyl-5-methoxycarbonyl-2-methyl-4-(3-nitrophenyl)-l,4-dihydropyridine- 3-carboxylic acid (4.5 g) in acetic acid (35 ml) were added hydroxylamine hydrochloride (0.97 g) and sodium acetate (1.43 g), and the mixture was stirred at ambient temperature for 2.5 hours. After acetic anhydride (4.14 g) was added to this reaction mixture, the mixture was stirred at ambient temperature for 1.5 hours and at 95-100°C for additional 4 hours. The acetic acid and the excess of acetic anhydride were removed in vacuum, followed by adding water to the residue and it was neutralized with a saturated aqueous solution of sodium bicarbonate. This aqueous suspension was extracted twice with ethyl acetate, and the combined extract was washed with water, dried over anhydrous magnesium sulfate and evaporated to dryness under reduced pressure to give a reddish-brown oil (4.88 g), which was chromatographed over silica gel (150 g) with a mixture of... 

The main metabolic reaction is the deamination of amphetamine with the formation of phenylacetone, which is subsequently oxidized to benzoic acid, then conjugated with glycine to form hippuric acid. Side reactions include aromatic hydroxylation to form 4-hydroxyamphetamine (an active metabolite), the stereoselective [i-hydroxy-lation for the isomer (+) of amphetamine leading to the formation of norephedrine (phenylpropanolamine) and finally the N-oxidation leading to the formation of a hydroxylamine derivative. The products of the hydroxyl and aromatic N-oxides can be conjugated with sulfate or glucuronic acid [18]. 

Palomo75 report that various aromatic aldehydes can be converted to nitriles in 94-97% yield by refluxing the aromatic aldehyde, hydroxylamine hydrochloride, and magnesium sulfate in toluene or xylene, with p-toluencsulfonic acid as catalyst for 1.5 to 3 hr. The microwave-assisted process may prove better for aliphatic aldehydes and may be made even more attractive if the above process conditions could be refined to reduce or eliminate NMP—for instance, if both aldehyde and nitrile form a homogeneous liquid at the reaction temperature. 

Cyclohexanone Oxime (called Cyclohexanon -oxim in Ger), C6H1(J N.OH mw 113.16, N 12.39% hexag prisms (from ligroin), mp 88-90°, bp 204° (almost w/o decompn) readily sol in w mod sol in ale eth si sol in ligroin obtd from reaction of cyclohexanone hydroxylamine sulfate in alkaline soln (Ref 1). Yamamoto (Ref 2) reported that a mixt of AN (60%), Amm sulfate cyclohexanone oxime when placed in a steel pipe heated showed a borderline temp of 140° for its explosivity. Mixts contg 50 40% AN showed a temp of 150°. With less than 33% AN or below 130° no explns were observed. The low temp of expin is accounted far by the high vap pressure of fused cyclohexanone oxime which reacts with AN, resulting in a local temp rise up to 300°... 

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