A Convenient One-Pot Synthesis of Bis(indolyl)methane Derivatives and Evaluation of Their Nematicidal Activity against the Root Knot Nematode Meloidogyne incognita

Seven arylbis(indolyl)methanes were synthesized by electrophilic substitution reaction of aromatic aldehydes on indole using glacial acetic acid as catalyst in aqueous media under ultrasonic irradiation. The synthesized bis-indole derivatives were characterized using elemental analysis, (1)H and (13)C NMR, FT-IR spectroscopy, and mass spectrometry and were screened for their nematicidal activity against the root knot nematode Meloidogyne incognita. The efficiency of the synthesized compounds was evaluated in vitro by egg hatching and mortality tests. All tested compounds showed significant nematicidal potential, and the nitro substituted derivative, 3,3′-[(4-nitrophenyl)methylene]di(1H-indole), exhibited the highest activity.