Transformations of 6,7-difluoroquinoxaline with Indoles: Synthesis of Indole-Substituted 6,7-difluoroquinoxalines and Tris(indol-3-yl)methane Derivatives

6,7-Difluoroquinoxaline (1) reacted with 1- and 2-methylindoles (2a and 2b) with heating in AcOH to give products from substitution of H in the heterocyclic fragment (3a and 3b) and tris(indol-3-yl)methane derivatives (4a and 4b).