Hydrogen azide ethereal solution

A different reaction takes place between an ethereal solution of the disulfide and hydrogen azide this reaction proceeds according to Eq. (15). Probably the principal step of this reaction is the spontaneous decomposition of the disulfide into nitrogen, sulfur, and... 

An ethereal solution of some 100 g of the crude nitrile was allowed to spontaneously evaporate and crystallise. The crystalline slurry so produced exploded violently without warning. Previously such material had been found not to be shock-sensitive to hammer blows, but dry recrystallised material was very shock-sensitive. Traces of free hydrogen azide could have been present, and a metal spatula had been used to stir the slurry, so metal azides could have been formed. See Other CYANO COMPOUNDS, ORGANIC AZIDES... 

Since the distribution ratio of hydrogen azide between the two solvents ether and water is approximately 7 1, ethereal solutions may be prepared by extraction of aqueous solutions with ether. However, the procedure used by Frost, Cothran, and Browne6 is preferable. 

A 3 per cent solution of hydrazoic acid (synthesis 26A) is neutralized with an aqueous solution of pure potassium hydroxide. The resulting solution of potassium azide is concentrated on the steam bath to incipient crystallization. The solution is then made slightly acid with hydrazoic acid to replace the hydrogen azide lost by hydrolysis. A volume of ethyl alcohol twice that of the solution is added, and the solution is cooled in an ice bath. Since the solubility in alcohol of the alkali and alkaline earth azides is very slight (see table below), precipitation in the form of a white microcrystalline salt takes place readily. From 90 to 95 per cent recovery of the theoretical quantity of potassium azide can be effected. The precipitated azide is filtered on a Buchner funnel and washed with cold absolute alcohol and then with ether. Any traces of adhering solvent may be removed in a vacuum desiccator. In a typical run, 300 ml. of a solution of hydrazoic acid containing 8.5 g. of HN3 was neutralized with potassium hydroxide, and the isolation of potassium azide effected as indicated above. Yield 14.7 g. (91.5 per cent) KN3. 

See also Hydrogen bromide) Hydrogen azide, 77 ethereal solution, 77, 78 Hydrogen bromide, 39, 114, 149, 151, 152... 

Hydrogen azide (highly toxic) in ether (2.3 M, 20 ml) was added to an ice-cooled solution of dimethylbismuth A,A-bis(trimethylsilyl)amide (18.3 g, 45 mmol) in the same solvent (50 ml) in the dark, and the resulting mixture was stirred for 1 day. The white separated precipitate was washed with small portions of ether and dried in vacuo to give dimethylbismuth azide as a microcrystalline solid (11.0 g, 86%) [85ZN(B)1320]. 

This volume uses the three terms HN3, hydrazoic acid, and hydrogen azide. The ionic reaction form of HN3, displaying the character of a weakly dissociated acid, is called hydrazoic acid, regardless of whether it appears as a wet vapor or in solution. For other than aqueous solutions the solvent is included in the name, as in ethereal hydrazoic acid. Hence, HN3 is appropriately called hydrazoic acid in reactions that leave the N3 group intact, such as neutralization, complexation, or nucleophilic attack. 

A solution of hydrogen azide in ether is prepared as described previously. Fifty milliliters of this solution is diluted to 500 ml. with anhydrous ethyl ether and cooled in an ice-salt mixture. Pure, dry ammonia gas is slowly bubbled through this solution until precipitation is complete. This operation should be carried out in a well-ventilated hood. The precipitated ammonium azide is filtered and stored in a vacuum desiccator, which from time to time is alternately evacuated and filled with dry air, until the ether has completely evaporated. Yield 4.1 g. (74 per cent). The product is of a high degree of purity. 

Phenyl azide itself undergoes ring expansion in the presence of nitrogen and oxygen nucleophiles, and hydrogen sulflde (in diethyl ether solution) but, in ethylmercaptan, 2-ethyImercaptoaniline, the product of rearomatization, is formed in preference to azepine. This rearomatization product can easily be accommodated by formation of an aziridine by initial attack on benzazirine and subsequent C-N bond fission of the aziridine ... 

Caution. Although we have carried out this preparation without incident several times, copper azides, which are explosive, are intermediates in this reaction. This preparation should be conducted behind a safety shield. Pure 1,1 -diazidoferrocene has been reported to explode when heated rapidly above its melting point o/56°C. ° We strongly recommend carrying out the hydrogenation of l,r-diazidoferrocene without isolating it from its ether solutions. 

Davies MJ, Gilbert BC (1984) Electron spin resonance studies, part 68. Addition versus overall one-electron abstraction in the oxidation of alkenes and dienes by S04, Cl2, and OH in acidic aqueous solution. J Chem Soc Perkin Trans 2 1809-1815 Deeble DJ, Parsons BJ, Johnson GRA (1990) Reactions of the hydrogen atom with azide, bromide and iodide ions in aqueous solution. Radiat Phys Chem 36 487-491 Eibenberger FI, Steenken S, O Neill P, Schulte-Frohlinde D (1978) Pulse radiolysis and E.S.R. studies concerning the reaction of S04" with alcohols and ethers in aqueous solution. J Phys Chem 82 749-750... 

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