New dry arenediazonium salts, stabilized to an exceptionally high degree by the anion of o-benzenedisulfonimide

Arenediazonium o-benzenedisulfonimides 3 (20 examples, yield > 90%) were prepared in the dry state by diazotization of aromatic amines with i-pentyl nitrite and o-benzenedisulfonimide in glacial acetic acid or formic acid at 0-5 degrees C. Unlike most diazonium salts in the dry state, salts 3 are very highly stable.