A simple preparation of aryl methanesulfonates by thermal decomposition ofdry arenediazonium o-benzenedisulfonimides in methanesulfonic acid

Aryl methanesulfonates 3 (18 examples) were easily prepared by thermal deco mposition of dry arenediazonium o-benzene-disulfonimides 1 in methanesulfon ic acid (2). The reactions were carried out at temperatures between 60 and 120 degrees C for times between 0.5 and 8 h. The aryl methanesulfonates wer e obtained in reproducible yield of 70-90%, with few exceptions. In all cas es the o-benzenedisulfonimide (4) could be recovered in good yields which c an then be reused to prepare the salts 1. When thermal decomposition of sal ts 1 was carried out in trifluoromethanesulfonic acid (5) at 90-120 degrees C for 1-2 h, aryl trifluoromethanesulfonates 6 were obtained in 73-78% yie ld (3 examples).