Ethyl 2-{3-[(6-chloropyridin-3-yl)methyl]-2-(nitroimino)imidazolidin-1-yl}acetate

In the title compound, C13H16ClN5O4, the imidazole ring is in a slight envelope conformation. The dihedral angle between the pyridine ring and the four essentially planar atoms [maximum deviation 0.015 (2) Å] of the imidazole ring is 80.8 (1)°. In, the crystal, weak C—H⋯O and C—H⋯N hydrogen bonds are present. In addition, there are weak π–π stacking interactions between symmetry-related pyridine rings with a centroid–centroid distance of 3.807 (1) Å.

In the title compound, C 13 H 16 ClN 5 O 4 , the imidazole ring is in a slight envelope conformation. The dihedral angle between the pyridine ring and the four essentially planar atoms [maximum deviation 0.015 (2) Å ] of the imidazole ring is 80.8 (1) . In, the crystal, weak C-HÁ Á ÁO and C-HÁ Á ÁN hydrogen bonds are present. In addition, there are weakstacking interactions between symmetry-related pyridine rings with a centroid-centroid distance of 3.807 (1) Å .   Table 1 Hydrogen-bond geometry (Å , ). nitroguanidine moiety of imidacloprid is also a common site for metabolism via cleavage to the guanidine and reduction to di-nitro-imidacloprid. The insecticidal activity of nitroguanidine was found to be 10,000 fold higher than that of natural insecticide nicotine (Deshmukh et al., 2012). In mammalian systems the nitro group of imidacloprid has been postulated to be reduced to nitrosoguanidine and aminoguanidine and then cleaved to the guanidine and urea derivatives (Deshmukh et al., 2011). Therefore, in a search for new neonicotinoid insecticides with improved profiles, neonicotinoid derivatives containing N-oxalyl groups were designed and synthesized (Zhao et al., 2010).

Related literature
The molecular structure of the title compound is shown in Fig. 1. The bond lengths and angles are comparable to those common to related structures (Kapoor et al., 2011(Kapoor et al., ,2012Kant et al., 2012). The imidazole ring is in a slight envelope conformation with atom C9 forming the flap. The dihedral angle between the pyridine ring [N1/C2-C6] and the four essentially planar atoms [N8/N11/C10/C12 (maximum deviation 0.015 (2)Å for C12)] of the imidazole ring is 80.8 (1)°.
Experimental Imidacloprid (10.20 g, 0.04 mol) in 30 ml acetone, ethyl chloroacetate (7.32 g, 0.06 mol) was refluxed for about 24 h in presence of 10 g m K 2 CO 3 . An aliquot of sample was taken to monitor the progress of reaction by TLC. After completion of reaction, the hot reaction mixture was filtered to remove excess K 2 CO 3 . Filtrate was then dried under reduced pressure giving a white solid, Yield 80%. The synthesized compound was dissolved in methanol, by the process of slow evaporation a fine crystalline compound separated out.

Refinement
H atoms were positioned geometrically and were treated as riding on their parent C atoms, with C-H distances of 0.93-0.97 Å.

Figure 1
The molecular structure with ellipsoids are drawn at the 40% probability level. H atoms are shown as small spheres of arbitrary radii.