Preparation of Alkyl Azides

Preparation of alkyl azides The azide ion (N3 ), a good nucleophile, can displace leaving groups from 1° and 2° alkyl halides. Alkyl azides are easily prepared from sodium or potassium azides and alkyl halides. The reaction mechanism resemhles the formation of nitrile. 

Preparation of Alkyl Azides from Sodium Azide, Alkyl Iodides, or Bromides, and Carbitol Solvents at 95°C for 24 hr... 

Ahad, E. (1990) Process for the preparation of alkyl azide substituted hydroxy terminated polyethers. US Patent 4,891,438 Chem. Ahstr., (1988) 109,171140u. 

Alkyl azides. Sodium azide as such is of little use for preparation of alkyl azides by nucleophilic substitution reactions because of solubility problems. The reaction can be carried out under phase-transfer conditions with methyltrioctylam-monium chloride/NaN3.3 An even more effective polymeric reagent can be obtained by reaction of NaN3 with Amberlite IR-400.4 This reagent converts alkyl bromides, iodides, or tosylates into azides at 20° in essentially quantitative yield. The solvents of choice are CH3CN, CHC13, ether, or DMF. 

Substitutions. Etherificatioi transfer catalyst in dry media undo preparation of alkyl azides from j catalyst. ... 

Substitutions. Etherification of phenols with alkylating agents, a base, and phase transfer catalyst in dry media under microwave irradiation can be an effective method. For preparation of alkyl azides from alkyl bromides one can use surfactant pillared clays as catalyst. ... 

Preparation of Alkyl Azides. A hydroazidation reaction similar to the reaction of Eq. 49 permits preparation of alkyl azides (Eq. 50), 215... 

Preparation of alkyl azides.1 Because it is easy to prepare, stable, and soluble in low-boiling organic solvents such as CHC13, it is the reagent of choice for reaction with alkyl halides to form the corresponding alkyl azides in yields of 60-96%. With the more reactive alkyl halides, in particular alkyl bromides, the reaction is... 

Alkyl azides. This quaternary ammonium sail is a suitable catalyst for the phase-transfer preparation of alkyl azides from alkyl bromides (iodides) and sodium azide in an aqueous medium yields are 74-93%. 

Phase-transfer catalysis preparation of alkyl azides. W. P. Reeves and M. L. Bahr,... 

Preparation of Alkyl Azides Through sp C-H Bond Azidation... 

Almost simultaneously. Jiao and coworkers reported a similar strategy for the preparation of alkyl azides from aliphatic carboxylic acids by using a catalytic amount of AgF in combination with benzenesulfonyl azides as the azide source (Scheme 6.33) [91]. A series of primary, secondary, and tertiary alkyl azides are prepared in good yields. The EPR experiments provide strong evidence for the SET process to generate carbon radical. In addition, DPT calculations further supported the SET process followed by a stepwise Sh2 reaction to give the azide product. On the basis of EPR experiments and DPT calculations, a possible mechanism that is similar to the one suggested in Scheme 6.32b was proposed for our sequence. 

General. Diphenyl phosphorazidate is a readily available, nonexplosive, and relatively stable azide widely used as a reagent in peptide synthesis, " and as a versatile reagent in a wide array of organic transformations. DPPA has been successfully utilized in the synthesis of a-amino acids and o-aryl carboxylic acids direct preparation of thiol esters from carboxylic acids and thiols the stereospecific preparation of alkyl azides and the phosphorylation of alcohols and amines The application of DPPA in a modified Curtius reaction permits a simple one-step conversion of carboxylic acids to urethanes under mild reaction conditions. DPPA acts as a nitrene source, and can undergo 1,3-dipolar cycloaddition reactions. The Curtius degradation of carboxylic acids in the presence of f-butanol gives the Boc-protected amine directly (eq 1). 

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