1-aryl-3,3-dialkyltriazenes: A convenient synthesis from dry arenediazonium o-benzenedisulfonimides - A high yield break down to the starting dry salts and efficient conversions to aryl iodides, bromides and chlorides

This research comprises three parts. The first part regards the synthesis o f 1-aryl-3,3-dialkyltriazenes 3 by reaction of dry arenediazonium o-benzene disulfonimides 1, also coming from weakly basic aromatic amines with dimeth ylamine or diethylamine in aqueous solution at 0-5 degreesC. Yields were us ually greater than 90% and there was the possibility of recovering the o-be nzenedisulfonimide (5), which could be roused to prepare the salts 1. In th e second part it was demonstrated that there is the possibility of reconver ting the triazenes 3 into the starting stable dry salts I by using 5 as aci d. The reactions were carried out in glacial acetic acid at 50-55 degreesC and normally afforded salts I in yields of around 90-99%. The third part co ncerns the setting up of two procedures for the conversion of 3 to aryl iod ides 9, bromides 10 and chlorides 11. Procedure A used the corresponding aq ueous hydrogen halides in acetonitrile at r.t. or 60 degreesC, sometimes in the presence of aqueous HBF4, sometimes Cri powder (25 examples, yields 65 %-88%). Procedure B usually used anhydrous methanesulfonic acid and tetraal kylammonium halides in anhydrous acetonitrile at temperatures varying from r.t. to 80 degreesC, sometimes in the presence of Cu (16 examples, yields 6 5-88%).