Imidazole 4-nitro-5-azido

Both 2-azido- and 2-nitro-imidazoles are accessible by nucleophilic displacement of the 2-diazonium fluoroborate. 

Diazonium salts of both 2- and 4-aminoimidazoles have been prepared, with a strongly acidic medium being preferred for the reactions. On occasion it is possible to isolate the intermediate nitrosoamines which are resistant to the action of dilute acid on storage, but which are subject to denitrosation when heated in alcohol solutions. The nitrosoamines can be converted into the diazonium salts. Diazonium fluoroborates have proved synthetically valuable for they can be transformed into the 2-nitro-, 2-azido- and 2-fluoro-imidazoles (80AHC(27)24l). The derived diazonium salts are also capable of coupling reactions (Scheme 118) (72CHE1533). 

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