Theophylline as a new and green catalyst for the one-pot synthesis of spirobenzoapyrano2,3-cphenazine and benzoapyrano2,3-c phenazine derivatives under solvent-free conditions

摘要

A green,convenient,high yielding and one-pot procedure for the synthesis of novel spiro[benzo[a]pyrano [2,3-c]phenazine] derivatives by domino multi-component condensation reaction between 2-hydroxynaphthalene-1,4-dione,benzene-1,2-diamines,ninhydrine,and malononitrile in the presence of a catalytic amount of 1,3-dimethyl-7H-purine-2,6-dione (theophylline) as an expedient,eco-friendly and reusable solid base catalyst under thermal,microwave irradiation and solvent-free conditions.This procedure has also been applied successfully for the synthesis of benzo[a]pyrano[2,3-c]phenazines.