Crystal structures of 2-methoxyisoindoline-1,3-dione, 1,3-dioxoisoindolin-2-yl methyl carbonate and 1,3-dioxo-2,3-dihydro-1H-benzo[de]isoquinolin-2-yl methyl carbonate: Three anticonvulsant compounds

Abstract

The title compounds, C9H7NO3, (1), C10H7NO5, (2), and C14H9NO5, (3), are three potentially anticonvulsant compounds. Compounds (1) and (2) are isoindoline derivatives and (3) is an isoquinoline derivative. Compounds (2) and (3) crystallize with two independent molecules (A and B) in their asymmetric units. In all three cases, the isoindoline and benzoisoquinoline moieties are planar [r.m.s. deviations are 0.021Å for (1), 0.04 and 0.018Å for (2), and 0.033 and 0.041Å for (3)]. The substituents attached to the N atom are almost perpendicular to the mean planes of the heterocycles, with dihedral angles of 89.7(3)° for the N-O-Cmethyl group in (1), 71.01(4) and 80.00(4)° for the N-O-C(=O)O-Cmethyl groups in (2), and 75.62(14) and 74.13(4)° for the same groups in (3). In the crystal of (1), there are unusual intermolecular C=O⋯C contacts of 2.794(1) and 2.873(1)Å present in molecules A and B, respectively. There are also C-H⋯O hydrogen bonds and π-π interactions [inter-centroid distance = 3.407(3)Å] present, forming slabs lying parallel to (001). In the crystal of (2), the A and B molecules are linked by C-H⋯O hydrogen bonds, forming slabs parallel to (10-1), which are in turn linked via a number of π-π interactions [the most significant centroid-centroid distances are 3.4202(7) and 3.5445(7)Å], forming a three-dimensional structure. In the crystal of (3), the A and B molecules are linked via C-H⋯O hydrogen bonds, forming a three-dimensional structure, which is consolidated by π-π interactions [the most significant inter-centroid distances are 3.575(3) and 3.578(3)Å].