Synthesis of Indeno[1,2-b]benzofurans using TPAB as Highly Efficient and Recoverable Catalyst

Herein we report the synthesis of some novel indeno[1,2-b]benzofuran derivatives by reaction of ninhydrin with cyclic 1,3-dicarbonyl compounds including cyclopentane-1,3-dione, cyclohexane-1,3-dione, dimedone, 4,4-dimethylcyclohexane-1,3dione, meldrum’s acid, barbituric acid, thiobarbituric acid, 1,3-dimethylbarbituric acid and indane-1,3-dione. We also used tetrapropylammonium bromide (TPAB) as an organocatalyst.