From hydrazoic acid

Thiatriazole-5-thiol and its salts are readily obtained from the water-soluble alkali or alkaline earth azides with CS2 at 40 °C <64AHC(3)263>. However, these salts should be handled with extreme care as violent explosions have been reported when the alkali salts are spread on a porous plate or rubbed with a spatula. The slightly soluble heavy-metal salts are very sensitive to shock even under water. An improved method for the preparation and storage of sodium thiatriazole-5-thiolate has been reported. The free acid is obtained by addition of concentrated hydrochloric acid to a chilled solution of the sodium salt but can also be prepared from hydrazoic acid and carbon disulfide (Scheme 38). 

The azides, except those of mercury) ), Hg(l,i, thalliura(l), 11(1), copper. Cu, silver, Ag, and lead, Pb, are readily prepared from hydrazoic acid and the oxide or carbonate of the metal, or by metathesis of the metal sulfate with barium azide. They are all thermally unstable, giving nitrogen and free metal or occasionally nitride. The azide ion appears to resonate between four structures ... 

Recently the tetrahydrofuran ring of a hemiacetal (45) was enlarged187 by inserting nitrogen from hydrazoic acid to obtain 36 [Eq. (33)]. This method was used for the formation of a 5,6-dihydro-4/f-1,3-oxazine steroid. 

Figure 9. Pure lead azide made from hydrazoic acid and lead nitrite.

The general pattern of diaziridine synthesis is probably also followed by three-membered ring formation from perfluorinated aminals " as well as by a diaziridine synthesis from hydrazoic acid." In the course of the difluorodiazirine synthesis of Mitsch," perfluoromethylenediamine 96 is defluorinated by ferrocene. 

This relatively safe azide has been prepared from hydrazoic acid and tetra-n-butylammonium hydroxide. It is conveniently prepared in quantitative yield from a mixture of tetra-n-butylammonium hydroxide and sodium azide con-... 

The above preparations in aqueous media incorporate some unavoidable hydrolytic decomposition (therefore recrystallization from hydrazoic acid), which is reduced in alcohol media. For example, lithium chloride [82] may be... 

The above methods involve synthesis of the azide group itself and should only be considered when the commercial sodium azide cannot be sufficiently purified or its preparation from hydrazoic acid is not feasible, as may be the case when isotope-enriched samples ( N) are needed. In the majority of cases, however, sodium azide is best prepared via hydrazoic acid. Purifying the commercial... 

Aqueous solutions of calcium azide are obtained from hydrazoic acid and calcium hydroxide an excess of the latter is precipitated as carbonate by bubbling in CO2 [62,116]. The solution is then concentrated, reacidified with hydrazoic acid, and precipitated with alcohol, acetone, or mixtures of these ether may be added to enhance the yield. Instead of the hydroxide, calcium carbonate [117,118] or oxide [73,119] have been used, but hydroxide yields a purer product [39]. If ammonium azide is available, its aqueous solution may be reacted with excess calcium hydroxide according to... 

Normal boron azide, B(N3)3, is a white solid and is chemically not very stable. The compound explodes when shocked mechanically or thermally and has a strong tendency to decompose hydrolytically. The only known synthesis starts from hydrazoic acid and diborane and yields the boron azide contaminated with boron hydrogen azides. The compound is ether soluble [231 ] ... 

Curtius [197] made hydrazine azide, (N2Hs)N3, in 1891 from hydrazoic acid and hydrazine, both of which he had discovered in the two preceding years. Today, the compound has found application in rocket fuel technology. 

Apart from hydrazoic acid, purine derivatives were also used as the nucleophiles by the Jacobsen group (Scheme 19.33). With ent-4 as the catalyst, the aza-Michael addition of 6-substituted purines to various a,p-unsaturated ketones bearing aliphatic p-substituents proceeded well, delivering the corresponding adducts in 60-95% yields, 14 1- > 99 1 of N9/N7, and 90-99% enantiomeric excess. Meanwhile, cx,p-unsaturated imides were... 

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