An example of the reactivity of sulfonamides as nucleophiles is the intramolecular reaction with a nitrile group as an electrophile. The key intermediates were obtained via the diazotization of aniline 105 for the preparation of sulfonyl chloride 106, which is subsequently converted to sulfonamide 107 by the treatment with ammonia. When heated in concentrated sulfuric acid, compound 107 undergoes cyclization to form cyclic imidosulfonamide 108, which can be further converted to amidosulfonamide 109 through alkaline hydrolysis. Both sultams 108 and 109 could be subjected to ring-opening reactions under acidic or basic conditions, respectively, which resulted in the formation of derivative 110 (Scheme 14).