Potassium azide, reaction with

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 nucleophilic displacement reactions with azide, primary amines, thiols and carboxylatc salts arc reported to be highly efficient giving high (>95%) yields of the displacement product (Table 9.25). The latter two reactions are carried out in the presence of a base (DBU, DABCO). Radical-induced reduction with tin hydrides is quantitative. The displacement reaction with phenolates,61j phosphines,6M and potassium phthalimide608 gives elimination of HBr as a side reaction. 

Azide 367 is prepared from 4-r -butyl-2-nitroaniline in 76% yield by its diazotization followed by treatment with sodium azide. In a 1,3-dipolar cycloaddition with cyanoacetamide, azide 367 is converted to triazole 368 that without separation is directly subjected to Dimroth rearrangement to give derivative 369 in 46% yield. Reduction of the nitro group provides ortfc-phenylenediamine 371 in 91% yield <2000EJM715>. Cyclocondensation of diamine 371 with phosgene furnishes benzimidazol-2-one 370 in 39% yield, whereas its reaction with sodium nitrite in 18% HC1 leads to benzotriazole derivative 372, which is isolated in 66% yield (Scheme 59). Products 370 and 372 exhibit potassium channel activating ability <2001FA841>. 

Several explosive species in which three or more azido groups are bonded to tellurium have been well characterized.59 The salt [Te(N3)3][SbF6] is formed from the reaction of Te4[SbF6]2 with potassium azide in liquid sulfur dioxide. The neutral binary tellurium azide Te(N3)4 is prepared by the reaction of TeF4 (in CFC13)60 or TeF6 (in CH3CN)61 with trimethylsilyl azide. 

The importance of reactions with complex, metal hydrides in carbohydrate chemistry is well documented by a vast number of publications that deal mainly with reduction of carbonyl groups, N- and O-acyl functions, lactones, azides, and epoxides, as well as with reactions of sulfonic esters. With rare exceptions, lithium aluminum hydride and lithium, sodium, or potassium borohydride are the... 

V-Methyl-/V-(2-perlhioroalkyl)ethy I amines 17 (R = C4F9, QT n or C-xI i 7) were prepared from the azides 16 by sequential reaction with triphenylphosphine, methyl iodide and aqueous potassium hydroxide45. 

Treatment of the alcohol ( ) with trifluoromethylsulfonic anhydride (triflic anhydride) at -78 C afforded the ester (1 ) which could be isolated and characterized. We knew from previous experience (2J that sulfonyl esters vicinal to an isopropylidene acetal are relatively stable. The triflate T,) reacted cleanly with potassium azide and 18-crown-6 in dichloromethane at room temperature. The crystalline product [68% overall from (1 )] was not the azide ( ) but the isomeric A -triazoline ( )- Clearly the initially formed azide (18) had undergone intramolecular 1,3-cyclo-addition to the double bond of the unsaturated ester (21- ). The stereochemistry of the triazoline (1 ), determined by proton nmr spectroscopy, showed that the reaction was stereospecific. There are several known examples of this reaction ( ), including one in the carbohydrate series ( ). When the triazoline was treated with sodium ethoxide ( ) the diazoester ( ) was rapidly formed by ring-opening and was isolated in 85% yield, Hydrogenolysis of the diazo group of (M) gave the required pyrrolidine ester ( ) (90%). 

Amino-substituted selenophenes are in general unstable compounds, and are conveniently isolated as IV-acetyl or iV-formyl derivatives. An ortho situated electron-attracting substituent such as acetyl, formyl or nitro renders the amino compounds stable. Derivatives of this type can be diazolized and the resulting diazonium salts converted into azides (by reaction with azide ion) (75CR(C)(281)317) and selenocyanates (by reaction with selenocyanide ion) (79BSF(2)237). 3-Acetamidoselenophene can be thiocyanated or selenocyanated in the 2-position by treatment with bromine and potassium thiocyanate or potassium selenocyanate, respectively (78TL1797). 

Metal Azides. Vapor with silver or sodium azide forms explosive bromine azide.10 Metals. Impact-sensitive mixtures are formed from lithium or sodium in dry bromine.11 Potassium, germanium, antimony, and rubidium ignite in bromine vapor.12 Violent reaction occurs with aluminum, mercury, or titanium.13 Methanol. Vigorously exothermic reaction on mixing the liquids.14 Nonmetal Hydrides. At room temperature, violent explosion and ignition occur with silane and its homologs15,16 and with germane.17... 

Iron(n) salts mediated the coupling of trialkylboranes with KSGN to give RSCN via a radical process.553,554 Stereochemically pure ( )-l-thiocyanato-alkenes or ( )-l-azide-alkenes were obtained from alkynes when hydro-boration with disiamylborane was followed by reaction with potassium thiocyanate or sodium azide in the presence of copper(n) nitrate, copper(n) acetate, and small amount of water in polar aprotic solvent (Equation (116)).555... 

Diorganotetrapseudohalotellurates(IV) were obtained from tetrachlorotellurates(TV) or tetraiodotellurates(IV) via exchange reactions1 2. Silver cyanide was used to exchange chloride for cyanide1. Chloride and iodide were replaced by pseudohalides in reactions with potassium cyanate, potassium thiocyanate, or potassium azide. 

A related reaction occurs on pyrolysis of o-hydroxybenzal azides (33) which are readily obtained from the corresponding chlorides with potassium azide. By heating, in acetic acid or nitrobenzene, or without a solvent, they are converted into indoxazenes, possibly through inter-... 

Aminopolyhydroxynaphthalenes. This NH, synthon was used to convert the protected bromopolyhydroxynaphthalene derivative I to the protected aminopolyhydroxy-naphthalene derivative 2, the aromatic nucleus of an ansamycin. One advantage of this amination is the satisfactory yield, which occurs in spite of the steric factors usually observed in the reaction of bromides with potassium azide. 

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