I. Katsuyama et al., The identification, mechanism, and improved synthesis of a new and unique heterocyclic system with a fused imidazole ring, HETEROCYCLE, 54(2), 2001, pp. 721
The reaction of sampangine (1) with arylalkylamines resulted in unexpected
formation of a new and unique sampangine derivative with a fused imidazole
ring (3). The identification and formation mechanism of 3, as well as its i
mproved synthesis, are described.