189115-05-7Relevant academic research and scientific papers
Bis-amidines as useful building blocks for heterofulvenes and -fulvalenes
Mueller,Beckert,Goerls
, p. 601 - 606 (2007/10/03)
An easily feasible synthesis for bis-amidines of type 3 was developed via an aminolysis reaction of imidoyl chlorides 1 with gaseous ammonia. Depending on the nature of the electrophilic cyclization reagent, these amidines show a different reactivity. On treatment with orthoesters, the fused imidazoles 5 were obtained which involved the participation of two different kinds of nitrogen atoms in the cyclization. In contrast to this, carboxylic acid chlorides are able to react selectively at the NH2-groups under formation of the fulvenoid 4H-imidazoles 6. The same regioselectivity was observed for chlorodimethylimmonium chloride thus leading, via the dimerization of cyclic orthoamides, to the 1,4,5,8-tetraazafulvalenes 8.
