Abstract
In this research, a simple and efficient strategy for the straightforward synthesis
of tetracyclic dihydrochromeno[2,3-b]pyrrolo[3,4-e]pyridine-trione derivatives is presented by a sequential four-component reaction
of arylamines, dimethyl acetylenedicarboxylate, alkylamines, and 3-formylchromones
as readily available starting materials in MeOH at room temperature. The merit of
this sequential enamine formation/1,2-nucleophilic addition/intramolecular aza-Michael
addition is highlighted by its high energy conserving (short reaction times at room
temperature), excellent yields, metal-free catalyst, easy purification (the products
can be purified by simple filtration and washing with EtOH), and green and mild conditions
in a one-pot reaction. Presumably, there are no previous reports for the synthesis
of these classes of heterocyclic dihydrochromeno[2,3-b]pyrrolo[3,4-e]pyridine-trione derivatives.
Key words
arylamine - dimethyl acetylenedicarboxylate - alkylamine - α-aminomaleimides - formylchromones
- multicomponent reactions
