NOVEL CYCLIZATION REACTIONS OF DICHLOROAZODIENES

The novel cyclization reactions of the in;situ generated 1-carboxyethy l-3-phenyl-4,4-dichloroazodiene were found to give N-aminopyrroles and pyridazines when combined with acyclic enamines,Table 1. However, rea ctions with cyclic enamines gave the N-aminopyrroles, pyridazines, a d ihydropyridazine as products as well as the non-cyclized enamine inter mediates, Table 2. The enamines 10c and 11c could be converted to the N-aminopyrroles 10a and 11a simply upon heating to higher temperatures indicating a stepwise mechanism. The examples described here are the first reported cyclization reactions for dichloroazodienes.