Cuprous azide bromide

Examples of the three mechanistic types are, respectively (a) hydrolysis of diazonium salts to phenols89 (b) reaction with azide ion to form aryl azides90 and (c) reaction with cuprous halides to form aryl chlorides or bromides.91 In the paragraphs that follow, these and other synthetically useful reactions of diazonium intermediates are considered. The reactions are organized on the basis of the group that is introduced, rather than on the mechanism involved. It will be seen that the reactions that are discussed fall into one of the three general mechanistic types. 

Examples of the three mechansims are, respectively (a) hydrolysis of aryl diazonium salts to phenols (b) reaction of aryl diazonium ions with Ns to give the aryl azides " and (c) the Sandmeyer reaction, involving cuprous chloride or bromide for synthesis of aryl halides. Specific synthetically important substitution processes are considered in the succeeding sections. 

Several polyfluorinated aryl azides (CeFs-Nj, /J-Ns CeFi Ns, p-Cl CsFi Nj, and i CFJ C F4-Ns) have been synthesized by treatment of the corresponding fluorides with sodium azide in dirnethylformamide. Catalytic hydrogeno-lysis of the azide C,FB-CHg CH(N3) COjH, prepared by Meerwein arylation of acrylic acid with pentafluorobenzenediazonium bromide-cuprous bromide and treatment of the product, a-bromo-/3-pentafluorophenyIpropionic acid (45), with sodium azide, has been used to obtain ( >pentafluorophenyl-alanine this a-amino-acid has also been prepared by the aziactone route shown in Scheme 22 and by the acetamidomalonate procedure depicted in Scheme 23 (the preferred method). Application of the last method to p-MeO-CjFB-CHjBr has been used to obtain the fluoro-tyrosine ( )-p-... 

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