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 (AandB) in their asymmetric units. In all three cases, the isoindoline and benzoisoquinoline moieties are planar [r.m.s. deviations are 0.021 Å for (1), 0.04 and 0.018 Å for (2), and 0.033 and 0.041 Å 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—Cmethylgroup in (1), 71.01 (4) and 80.00 (4)° for the N—O—C(=O)O—Cmethylgroups 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 moleculesAandB, 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), theAandBmolecules are linked by C—H...O hydrogen bonds, forming slabs parallel to (10-1), which are in turn linkedviaa 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), theAandBmolecules are linkedviaC—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].