Azides of Carbon

The other heteroazide of carbon, carbonyl azide, 0=C(N3)2, displays an enhanced sensitivity. It detonates on mild mechanical or thermal shock and is even set off when exposed to bright daylight. The compound was synthesized in 1894 from carbazide and nitrite [250], but owing to its instability has found no applications. 

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The preparation of amines by the methods described m this section involves the prior synthesis and isolation of some reducible material that has a carbon-nitrogen bond an azide a nitrile a nitro substituted arene or an amide The following section describes a method that combines the two steps of carbon-nitrogen bond formation and reduction into a single operation Like the reduction of amides it offers the possibility of prepar mg primary secondary or tertiary amines by proper choice of starting materials... 

No other compounds which were considered to be thiatriazoles had been prepared at this time. However, one other thoroughly investigated compound, the reaction product of carbon disulfide and sodium azide, which had generally been considered as azidodithiocarbonic acid, was shown by Lieber et al. to be a thiatriazole. 

Related reactions are those of sodium azide with carbon disulflde to give 5-mercapto-l,2,3,4-thiatriazole (see 8ection IV) and with thio-carbonyl chloride to give 5-chloro-l,2,3,4-thiatriazole. ... 

The free acid, l,2,3,4-thiatriazole-5-thiol, may be prepared from hydrogen azide and carbon disulfide, but the simplest way to obtain the acid is to treat a chilled solution of the sodium salt with concen-... 

Catalytic transfer hydrogenations for the reduction of carbon-carbon double bonds are illustrated in Scheme 4.18. Reductions of azide functionalities to amines with lipases suspended in organic media under microwave conditions have also been reported [206]. 

Huisgen, R. Szeimies, G. Moebius, L. 1,3-Dipolar cycloadditions XXXll. Kinetics of the addition of organic azides to carbon-carbon multiple bonds. Chem. Ber. 1967,100, 2494-2507. 

The pseudohalogen concept can be extended (i) to some special nonplanar anions such as CF3, (ii) to heavier elements (isovalence electronic exchange of O by S, Se, Te of N by P etc. in SCN , SeCN , TeCN , P(CN)2 ) " and (iii) to derivatives such as the five-membered ring anion [CS2N3] which can be obtained in the reaction of carbon disulfide and sodium azide as shown by Sommer as early as 1915. The introduction of heavier elements, however, results in weaker delocalization effects due to the formation of weaker tt-bonds. 

Anhydro-5-hydroxy-1,2,3,4-oxatriazolium hydroxides (4) are relatively stable at elevated temperatures under neutral and salt-free conditions. However, prolonged heating of (17) in the presence of lithium chloride gives rise to elimination of carbon dioxide with formation of an azide which can be trapped by 1,3-dipolar cycloaddition to an alkyne (Scheme 2) <68CB536>. 

Sylwester and Dervan s assignment was supported by the observation that the violet photoproduct decomposes to N2 and H2 upon warming the glass or upon further irradiation of the glass. Furthermore, photolysis of 62 in argon at 10 K leads to the disappearance of the IR spectrum of the azide and the appearance of new bands at 2865, 2808, 2141, 1863, 1574, and 1003 cm. The 2141-cm band is due to the formation of carbon monoxide. The band at 1574 is assigned to the... 

Lead azide, like hydrazoic acid, is liable to undergo oxidation and reduction reactions. It is partially decomposed by atmospheric oxygen to form free hydrazoic acid, nitrogen and ammonia. This reaction is promoted by the presence of carbon dioxide in the air. When boiled in water, lead azide undergoes slow decomposition with the evolution of hydrazoic acid. 

Diazide of carbonic acid (V) is exceptionally sensitive to friction it explodes on contact with a glass rod (Curtius and Heidenreich [149]) Succinyl azide [150] and other acyl azides [151] behave similarly. 

The alkali azidodithiocarbonates may be obtained by the action of carbon disulphide vapour on an aqueous solution of the alkali azide at 40° C.2 With a 1 per cent, solution of sodium azide the action proceeds quantitatively ... 

Potassium azide reacts with iodine in the presence of carbon disulphide to form potassium iodide and nitrogen as the final products, but the reaction appears to proceed according to the following scheme 1... 

The most common preparations of amines on insoluble supports include nucleophilic aliphatic and aromatic substitutions, Michael-type additions, and the reduction of imines, amides, nitro groups, and azides (Figure 10.1). Further methods include the addition of carbon nucleophiles to imines (e.g. the Mannich reaction) and oxidative degradation of carboxylic acids or amides. Linkers for primary, secondary, and tertiary amines are discussed in Sections 3.6, 3.7, and 3.8. 

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