Sodium azide, reaction with azides

Sodium azide, reaction with l butyl chloroacetate, 46, 47 reaction with diazomum salt from o amino-f> -ni trobiphcny L, 46, 86 Sodium chlorodifluoroacetate, 47, SO reaction with tnphenylphosphme and benzaldehyde, 47, SO Sodium ethoxide, 46, 2S reaction with diethyl succinate, 46,2S Sodium formate as reducing agent in preparation of palladium catalyst, 46, 90... 

Sodium azide, reaction with 1-butyl chloroacetate, 46, 47 reaction with diazonium salt from -ammo-/> -nitrobiphcnyl, 46,... 

The Cunius degradation of acyl azides prepared either by treatment of acyl halides with sodium azide or trimethylsilyl azide [47] or by treatment of acyl hydrazides with nitrous acid [f J yields pnmarily alkyl isocyanates, which can be isolated when the reaction is earned out in aptotic solvents If alcohols are used as solvents, urethanes are formed Hydrolysis of the isocyanates and the urethanes yields primary amines. 

An example of asymmetric synthesis involving cycloaddition of an azide to dimethyl acetylenedicarboxylate is depicted in Scheme 172. Thus, asymmetric auxiliary 1042 reacts with styrene and sodium azide to generate azide 1043 in 90% yield and 94% diastereomeric purity. The following reaction (Scheme 172) with dimethyl acetylenedicarboxylate converts azide 1043 into triazole 1044 in 75% yield. Finally, the bond with selenium is cleaved by treatment with triphenyltin hydride and AIBN to furnish triazole 1045 in 80% yield and preserved optical purity (94%) <2003AGE3131>. 

An excess of sodium azide reacts with 2,3-allenoates to give ,/)-unsaturatcd eno-ates 499. No reaction was observed with 4,4-disubstituted 2,3-allenoates [225]. 

Sodium azide reacts with various epoxides at 25°-30°C at pH 6-7 to give azido alcohols [57-59]. The use of harsh conditions as earlier employed by Van der Werf et al. [59] (16-40 hr reflux in dioxane) led to the production of 1,3-diazidopropanol instead of l-azido-3-chloro-2-propanol when starting with epichlorohydrin. Several representative examples of the conditions and products of the reaction of azides with epoxides are shown in Table V. 

Reaction of Methyl 4,6-Dichloro-4,6-dideoxy-a-D-galactopyranoside 2,3-Di(chloro-sulfate) with Sodium Azide, and with Sodium Bromide, in A/,2V-Dimethylformamide, H. Parolis, W. A. Szarek, and J. K. N. Jones, Carbohydr. Res., 19 (1975) 97-105. 

What are the structures of the products of reaction of lH-pentafluoro-propene with sodium azide or triethylammonium azide ... 

Racemic or achiral a-azido acids are synthesized by direct azide substitution on commercially available a-bromo carboxylic acids or by radical bromination of carboxylic acids followed by azide substitution. In general, azido acids are stored in the dark to avoid photolytic degradation with loss of nitrogen temperatures above 50 °C should be avoided. Radical a-bromination of a-branched carboxylic acids as required for the synthesis of a,a-dialkyl or a,a-diaryl amino acids is performed with A-bromosuccinimide. This is followed by nucleophilic substitution with sodium azide or other azide donors, e.g. tetrabutylannmonium azide, to produce achiral or racemic a-azido-a,a-diaIkyl or a-azido-a,a-diaryl carboxylic acids (Scheme 74).Synthesis of more sterically hindered a,a-disubstituted azido acids leads to hydroxy compounds when prolonged reaction times are required and not sufficient care is taken to operate under dry conditions and an inert atmosphere.t ... 

For some of the simple 4,5-dihydro-3//-pyrazoles not available by the diazoalkane-alkene route, an alternative to the hydrazine reaction discussed in the last section is oxidative cyclization of a 1,3-diamine. Hence, an alternative preparation of the ketone 1 is to react 2,4-dibromo-2,4-dimethylpentan-3-one with sodium azide, reduce the azide groups with ammonium polysul-fide " and oxidatively cyclize with sodium hypobromite. " ... 

There are many ways to make the reaction work well, one of the most popular using sodium azide buffered with ammonium chloride with LiCl in DMF. The product is the tetrazole anion 88 and the tetrazole 87 is released on acidification. The example 91 shows that the yields are excellent and that functionality can be included in the side chain.8... 

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