imidazolones in high yields, instead of amidines with chemiluminescence (CL). The corresponding imidazolols were believed to intermediates and they were successfully obtained by treating the peroxides with DMSO without the base. The diminished CL was because of the reduction of the hydroperoxides with DMSO. The imidazolols subsequently underwent smooth base‐mediated rearrangement to afford imidazolones