Azide hydrides

Nitrogen, phosphorus and arsenic form more than one hydride. Nitrogen forms several but of these only ammonia, NHj, hydrazine, N2H4 and hydrogen azide N3H (and the ammonia derivative hydroxylamine) will be considered. Phosphorus and arsenic form the hydrides diphosphane P2H4 and diarsane AS2H4 respectively, but both of these hydrides are very unstable. 

Alkyl azides prepared by nucleophilic substitution of alkyl halides by sodium azide as shown m the first entry of Table 22 3 are reduced to alkylammes by a variety of reagents including lithium aluminum hydride... 

Reduction of an azide a nitrile or a nitro compound furnishes a primary amine A method that provides access to primary secondary or tertiary amines is reduction of the carbonyl group of an amide by lithium aluminum hydride... 

Alkyl azides prepared by nucleophilic substitution by azide ion in primary or secondary alkyl halides are reduced to primary alkylamines by lithium aluminum hydride or by catalytic hydrogenation... 

The 3-substituents in 3-nitro- and 3-phenylsulfonyl-2-isoxazolines were displaced by a variety of nucleophiles including thiolate, cyanide and azide ions, ammonia, hydride ions and alkoxides. The reaction is pictured as an addition-elimination sequence (Scheme 54) (72MI41605, 79JA1319, 78JOC2020). 

Hydrazoic acid Hydrides, volatile Hydrogen cyanide (unstabilized) Hydrogen (low pressure) Hydrogen peroxide (> 35% water) Magnesium peroxide Mercurous azide Methyl acetylene Methyl lactate Nickel hypophosphite Nitriles > ethyl Nitrogen bromide... 

Iodine azide, on the other hand, forms pure adducts with A -, A - and A -steroids by a mechanism analogous to that proposed for iodine isocyanate additions. Reduction of such adducts can lead to aziridines. However, most reducing agents effect elimination of the elements of iodine azide from the /mwj -diaxial adducts of the A - and A -olefins rather than reduction of the azide function to the iodo amine. Thus, this sequence appears to be of little value for the synthesis of A-, B- or C-ring aziridines. It is worthy to note that based on experience with nonsteroidal systems the application of electrophilic reducing agents such as diborane or lithium aluminum hydride-aluminum chloride may yet prove effective for the desired reduction. Lithium aluminum hydride accomplishes aziridine formation from the A -adducts, Le., 16 -azido-17a-iodoandrostanes (97) in a one-step reaction. The scope of this addition has been considerably enhanced by the recent... 

The properties of chlorine azide resemble those of bromine azide. Pon-sold has taken advantage of the stronger carbon-chlorine bond, i.e., the resistance to elimination, in the chloro azide adducts and thus synthesized several steroidal aziridines. 5a-Chloro-6 -azidocholestan-3 -ol (101) can be converted into 5, 6 -iminocholestan-3l -ol (102) in almost quantitative yield with lithium aluminum hydride. It is noteworthy that this aziridine cannot be synthesized by the more general mesyloxyazide route. Addition of chlorine azide to testosterone followed by acetylation gives both a cis- and a trans-2iddMct from which 4/S-chloro-17/S-hydroxy-5a-azidoandrostan-3-one acetate (104) is obtained by fractional crystallization. In this case, sodium borohydride is used for the stereoselective reduction of the 3-ketone... 

The azidohydrins obtained by azide ion opening of epoxides, except for those possessing a tertiary hydroxy group, can be readily converted to azido mesylates on treatment with pyridine/methanesulfonyl chloride. Reduction and subsequent aziridine formation results upon reaction with hydrazine/ Raney nickel, lithium aluminum hydride, or sodium borohydride/cobalt(II)... 

After drying under vacuum this iodo azide (2.43 g) is suspended in 50 ml of ether and added with stirring to a cold (0°) slurry of lithium aluminum hydride (1.2 g) in 70 ml of anhydrous ether in a 250 ml 3-necked flask (fitted with a reflux condenser and a mechanical stirrer with a Teflon blade). The remaining traces of the iodo azide are rinsed into the reaction flask with three 10 ml portions of ether. The reaction mixture is allowed to warm to room temperature and to stir for a total period of 11 hr. 

A solution of hydrazoic acid (prepared from about 30 g sodium azide) in ca. 200 ml chloroform is prepared in a well-ventilated hood. Cholesterol (15 g) is dissolved in the hydrazoic acid solution and 3.5 ml of triethylamine is added. The reaction mixture is then stirred at room temperature while 7 g of A-chlorosuccinimide is added. The reaction mixture is allowed to stand overnight and then the chloroform solution is washed successively with dilute sodium bisulfite, dilute soldium bicarbonate solutions and finally with water. The chloroform extract is then dried (Na2S04) and the solvent removed in vacuo. The residue is crystallized from ethanol to yield ca. 8.5 g of (101) in colorless needles mp 138-139°. The chloro azide is reduced to the aziridine by lithium aluminum hydride according to the foregoing procedure. 

The azido mesylate may also be reduced with lithium aluminum hydride in the same manner as previously described for iodo azide reductions. The sodium borohydride/cobalt(II)tris(a,a -dipyridyl)bromide reagent may be used, but it does not seem to offer any advantages over the more facile lithium aluminum hydride or hydrazine/Raney nickel procedures. 

Nitrogen forms more than 20 binaiy compounds with hydrogen of which ammonia (NH3, p. 420), hydrazine (N2H4, p. 427) and hydrogen azide (N3H, p. 432) are by far the most important. Hydroxylamine, NH2(OH), is closely related in structure and properties to both ammonia, NH2(H), and hydrazine, NH2(NH2) and it will be convenient to discuss this compound in the present section also (p. 431). Several protonated cationic species such as NH4+, N2H5+, etc, and deprotonated anionic species such as NH2 , N2H3 , etc. also exist but ammonium hydride, NH5, is unknown. Among... 

Butyl alcohol in synthesis of phenyl 1-butyl ether, 46, 89 1-Butyl azidoacetate, 46, 47 hydrogenation of, 46, 47 1-Butyl chloroacetate, reaction with sodium azide, 46, 47 lre l-4-i-BUTYLCYCLOHEXANOL, 47,16 4-(-Butylcyclohexanonc, reduction with lithium aluminum hydride and aluminum chloride, 47, 17 1-Butyl hypochlorite, reaction with cy-clohexylamine, 46,17 l-Butylthiourea, 46, 72... 

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. 

Selenium oxide (SeO,) [7446-08-4], 25 Silane, tnchloro [ 10025-78-2], 83 Sodium azide [26628-22-8], 109 Sodium hydride [7646-69-7], 20 Stannane, tetrachloro- [7646-78-8], 97 Sulfuric acid, diethyl ester [64-67-5], 48 dimethyl ester [77-78-1], 62 Sulfuryl chloride isocyanate [1189-71-5], 41... 

Singlet oxygen [Oxygen, singlet], 51 Sodium acetate [Acetic acid, sodium salt], 33,49,66 Sodium azide, 109 Sodium hydride, 20 Sodium thiosulfate (Thiosulfuric acid (HjSj03), disodium salt], 120 Squalene [2,6,10,14,18,22 Tetracosa-... 

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