Product Subclass 3: Pyrimido[1,6-a]indoles and Related Benzo-Fused Ring Systems

Methods for the synthesis of pyrimido[1,6- a]indoles, indolo[1,2-c] quinazolines, and the less-common pyrido[2',1':2,3]pyrimido[1,6-a]indol-5-ium ring systems are reviewed in this chapter. Indolo[1,2-c] quinazolines are the most represented in the literature, most often being accessed via cyclization of either 2-(2-aminoaryl)indoles or 2-(2-haloaryl)indoles, although a variety of additional approaches are described.