Crystal structure of diethyl {2,2,2-trichloro-1-[2-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)-4-methylpentanamido]ethyl}phosphonate

The crystal structure of the intermediate product of the synthesis of phosphorylated 5-amino-1,3-oxazol-4-ylphosphonic acid derivatives is reported.


Chemical context
In early 1950, J. W. Cornforth noted that oxazole derivatives rarely occur in nature and were therefore not promising as new biologically active substances. Studies performed mostly during recent decades have shown that the oxazole ring occurs in a multitude of natural products and it has been widely employed as a component of biologically active compounds in medicinal chemistry (Jin et al., 2006). Various bacteria and marine organisms produce numerous antibiotics belonging to the oxazole series (Chamberlin et al., 1977;Bertram et al., 2001;Jansen et al.,1992;Moody & Bagley, 1998). Today, numerous oxazole-based synthetic bioregulators with strong antimicrobial, cytostatic, immune stimulating, neuroleptic, analgesic, and other kinds of biological activity are known (Turchi et al., 1986;Palmer et al., 2003). In particular, 5-amino-1,3-oxazole and its derivatives are well recognized for their potent and diverse bioregulation activity. Here we present the crystal structure of the title compound, which is an intermediate product of synthesis of phosphorylated 5-amino-1,3oxazol-4-ylphosphonic acid derivatives.
In the acetamide moiety, the lone pair of atom N2 is conjugated with the -system of the C O group. Thus, the sum of nitrogen valency angles is 359.3 and the C14-N2 bond length of 1.356 (3) Å is intermediate between that for a double and a single bond (1.28 and 1.45 Å , respectively; Allen et al., 1987). The C15-N2 bond has a typical value for a single bond at 1.442 (3) (9) , respectively], while angles O1-P1-O3 and O2-P1-O3 are not [109.82 (9) and 116.77 (9) ], which is probably due to molecular packing effects.
The CCl 3 group has typical values for the C-Cl distances (the mean C-Cl bond lengths is 1.773 Å ). In general, all bonding parameters and the dimensions of the angles in the title complex are in good agreement with those encountered in related complexes (Bhatti et al., 2010).

Figure 3
The crystal packing of the title compound viewed along the a axis. Intermolecular N-HÁ Á ÁO and C-HÁ Á ÁO hydrogen bonds are shown as dashed lines. Only selected H atoms are shown.

Figure 1
The molecular structure of the title compound with the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level.

Diethyl {2,2,2-trichloro-1-[2-(1,3-dioxo-2,3-dihydro-1H-isoindol-2-yl)-4-methylpentanamido]ethyl}phosphonate
Crystal data Special details Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.