Tetramethylguanidiniumchlorosulfonate ionic liquid (TMG IL): an efficient reusable catalyst for the synthesis of tetrahydro-1H-benzo[a]chromeno[2,3-c]phenazin-1-ones under solvent-free conditions and evaluation for their in vitro bioassay activity

Abstract

Medicinally important tetrahydro-1H-benzo[a]chromeno[2,3-c]phenazin-1-ones were synthesized by the straightforward, efficient and convenient approach of a three-component reaction between aldehydes, benzo[a]phenazin-5-ol and active methylene compounds under neat conditions in the presence of an ionic liquid, tetramethylguanidiniumchlorosulfonate (TMG IL). The TMG IL was used as a solvent and as a catalyst under reusable conditions. The observed higher product yields in a shorter reaction time and the use of environmentally benign reaction conditions are the merits of this reaction. The title compounds were screened for their antioxidant and anticancer activities, with the majority of them showing good bioassay activity.