2-[2-(Trimethylsilyl)ethyl]isoindoline-1,3-dione

In the course of our studies of silicon-containing anticancer compounds, the title compound, C13H17NO2Si, was synthesized. The geometrical parameters including the geometry about the Si atom are typical. The molecules form dimers via a weak C—H⋯O interaction described by the graph set R 2 2(10). The dimers are assembled in rows stacked in the crystallographic b-axis direction via π–π interactions with a 3.332 (3) Å separation between the rows.

In the course of our studies of silicon-containing anticancer compounds, the title compound, C 13 H 17 NO 2 Si, was synthesized. The geometrical parameters including the geometry about the Si atom are typical. The molecules form dimers via a weak C-HÁ Á ÁO interaction described by the graph set R 2 2 (10). The dimers are assembled in rows stacked in the crystallographic b-axis direction viainteractions with a 3.332 (3) Å separation between the rows.
The molecules form dimers via a weak C11-H11···O2 interaction with a distance of 3.443 (4) Å and an angle of 155°.
The pattern formed can be described in graph set notation as R 2 2 (10) (Grell et. al., 1999). The dimers are assembled into rows via weak π-π interactions with a distance of 3.366 (5) Å between atoms C13 in separate dimers. The rows are stacked in the crystallographic b direction.

Experimental
The title compound was obtained via a Mitsunubu reaction as described by Sen and co-workers (Sen & Roach, 1995). To a pre-dried 100 ml round bottom flask was added 2-(trimethylsilyl)ethanol (319 mg, 2.7 mmol). Additionally, potassium phthalimide (512 mg, 3.48 mmol) and triphenyl phosphine (913, 3.48 mmol) were added to the reaction flask. The flask was sealed with a rubber septum, evacuated, and then filled with an inert atmosphere (nitrogen). Subsequently, 30 ml of freshly distilled THF was added to the round bottom flask. In the dark, the flask was then wrapped with aluminium foil and diisopropyl azodicarboxylate (DIAD) was slowly syringed into the reaction flask. This mixture was allowed to stir at room temperature for four hours. Three ml of water was slowly injected into the reaction mixture, and the given suspension was allowed to stir for a few more minutes. The aluminium foil covering the reaction flask was removed and its contents were poured into an extraction flask. The aqueous phase was extracted 3-5 times with hexane and the resultant organic extracts were dried with MgSO 4 and filtered. The filtrate was mixed with silica gel and this slurry was dried under reduced pressure. The dry powder was loaded onto a pre-dry packed silica gel column and eluted with a gradient column. The desired material was collected using a 8:2 hexane:ethyl acetate mixture. The compound of interest was dried under reduced sup-2 pressure and recrystallized from dichloromethane to afford lustrous white needles (0.35 g, 1.41 mmol, 52% yield) for X-ray crystallography. Manipulation of air and moisture sensitive compounds was performed using standard high-vacuum line techniques. All solvents and reagents were obtained from Aldrich. 2-(trimethylsilyl)ethanol was purchased from Gelest. 1 H NMR spectra were obtained on a Varian Unity 500 spectrometer, 13

Refinement
All H-atoms were placed in idealized locations and refined as riding with appropriate thermal displacement coefficients U iso (H) = 1.2 or 1.5 times U eq (bearing atom). The data were collected at room temperature on a Bruker SMART X2S diffractometer in the automated mode and manually processed thereafter. Fig. 1. Molecular structure of (I). The thermal ellipsoids are shown at 30% probability level.  Refinement. Refinement of F 2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F 2 , conventional R-factors R are based on F, with F set to zero for negative F 2 . The threshold expression of F 2 > σ(F 2 ) is used only for calculating Rfactors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F 2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å 2 )
x y z U iso */U eq sup-4