Microwave-assisted reductive cyclization: an easy entry to the indoloquinolines and spiro[2H-indole-2,3′-oxindole]

Abstract

Synthesis of two linear indoloquinolines i.e. 6H-indolo[2,3-b]quinoline & 11-hydroxy-10H-indolo[3,2-b]quinoline, and spiro[2H-indole-2,3′-oxindole] from a common intermediate, (2-nitrophenyl)methylidene-dihydro-indolone derivative is described using microwave-mediated reductive cyclization as the key step.