Alkylaryl azides

Alkylaryl azides.3 Reaction of an alkylarene with DDQ and N3Si(CH3)3 in CHC13 at 25° results in replacement of a benzylic hydrogen by an azide group to give an alkylaryl azide in 50-95% yield. Hydrazoic acid can be used in place of azidotrimethylsilane, but this reaction is generally slower. 

Recently, Bandgar and Pandit have described a mild, efficient, and general method for the preparation of acyl azides from carboxylic acids and sodium azide using CC (Scheme 47). Various aryl, heteroaryl, alkylaryl, and alkyl carboxylic acids, on reaction with CC in the presence of sodium azide and A -methylmorpholine, undergo smooth conversion to the corresponding acyl azides in excellent yields <2002TL3413>. 

Bandgar et al. reported a general route for the synthesis of acyl azides from aryl, heteroaryl, alkylaryl and alkyl acids with cyanuric chloride (297) in the presence of sodium azide and (V-methylmorpholine. Acid activation can also be achieved using triphosgene. In fact, aromatic and aliphatic carboxylic acids react with triphosgene in the presence of sodium azide and triethylamine giving acyl azides in good yield (e.g. synthesis of 301). 

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