The title compound was prepared by cyclization of 2-(3,4-methylenedioxyphenyl)ethyl-3-hydroxyisoindolin-l-one in concentrated hydrochloric acid. The compound crystallizes in the orthorhombic space group Pca2(1) (No. 29) with a = 27.034(5) Å, b = 4.5093(9) Å, c = 10.667(2)Å, V = 1300.4(4) ų and Z = 4. The crystal consists of a single enantiomer. The molecule consists of two essentially flat moieties forming an dihedral angle of 116.3(2)°. The crystal slructure has intermolecular C-H-O interactions resulting in chains that run along the crystallographic c-axis.