Synthesis of a tetracyclic G^C scaffold for the assembly of rosette nanotubes with 1.7 nm inner diameter

The preparation of a tetracyclic self-complementary molecule for self-assembly into rosette nanotubes is described. An efficient approach is described to access the multifunctional pyrido[2,3-d]pyrimidine intermediate under mild conditions by using three regioselective [S.sub.N]Ar reactions at C2, C4 and C7 on the trichloro compound.