The Formation of Triaryl- s -triazine in the Chemiluminescence Reaction of Triarylimidazole and in the Photo-oxygenation of Triarylimidazole in the Presence of Ammonia

Abstract

2,4,6-Triphenyl-s-triazine (II) is formed either in the chemiluminescence reaction of 2,4,5-triphenylimidazole (I) in the presence of oxygen and a strong base or in the photolysis of I in alcohol in the presence of ammonia and oxygen. II is also formed in the sensitized photo-oxygenation of I in alcohol containing ammonia. It was found that II was produced by the reaction between the lophyl hydroperoxide (V), which was prepared from I and was known to be one of the intermediates in chemiluminescence reaction of I, and ammonia. Chemical and spectroscopic evidence that II is produced from V and not via the dioxetane-type peroxide (VI) nor N,N′-dibenzoylbenzamidine (IV), is given. II and several other 2,4,6-triaryl-s-triazines were found to be easily prepared from the corresponding triarylimidazoles by the sensitized photo-oxygenation in methanol in the presence of ammonium acetate and this provides a new method for the synthesis of triaryl-s-triazine.