Synthesis of N-substituted amidinoheteroles and their reactivity towards Burgess reagent

Abstract

N-Substituted amidinoimidazoles and amidinopyrroles were synthesized by the reaction of 2-cyanoimidazole and 2-cyanopyrrole with the corresponding ammonium salts in the presence of AlMe3 in toluene under reflux conditions. With the aim to investigate the transformation of the N-substituted amidino group to isonitrilium ion, N-mesitylamidinoimidazole and N-diisopropylphenylamidinopyrrole were allowed to react with the Burgess reagent. Instead of the desired deamination product, 1,2,4,6-thiatriazinone 1,1-dioxides were produced, which are heterocycles containing a part of the Burgess reagent and the K-area of amidinoheteroles.