(R)-2-[1-(2,6-Dichloro-3,4,5-trimeth­oxy­benzo­yl)pyrrolidin-2-yl]-4,4,5,5-tetra­methyl-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide

Wang, H.-B.; Xiang, Z.; Jing, L.-L.; Tian, M.; Sun, X.-L.

doi:10.1107/S1600536811010270

Volume 67
Part 4
Pages o985-o986
April 2011

Received 13 March 2011
Accepted 18 March 2011
Online 26 March 2011

Key indicators
Single-crystal X-ray study
T = 296 K
Mean (C-C) = 0.007 Å
R = 0.053
wR = 0.131
Data-to-parameter ratio = 14.3
Details

(R)-2-[1-(2,6-Dichloro-3,4,5-trimethoxybenzoyl)pyrrolidin-2-yl]-4,4,5,5-tetramethyl-4,5-dihydro-1H-imidazole-1-oxyl 3-oxide

Hai-Bo Wang,^a Zhuo Xiang,^a Lin-Lin Jing,^b Min Tian ^a and Xiao-Li Sun ^a ^*

^aDepartment of Chemistry, School of Pharmacy, Fourth Military Medical University, Changle West Road 17, 710032 Xi-An, People's Republic of China, and ^bDepartment of Pharmacy, Lanzhou General Hospital, Lanzhou Command, Lanzhou 730050, People's Republic of China
Correspondence e-mail: xiaoli_sun@yahoo.cn

In the title compound, C₂₁H₂₈Cl₂N₃O₆, the nitronyl nitroxide ring displays a half-chair conformation, whereas the pyrrolidine ring has an envelope conformation. These two rings are twisted to each other with N-C-C-N torsion angles around the connecting C-C bond of 48.9 (6) and -127.0 (5)°. The benzene ring is nearly perpendicular to the pyrrolidine ring, with torsion angles around the connecting C-C bond of 86.3 (6) and -97.7 (6)°. The crystal structure is stabilized by C-HO and C-H [pi] hydrogen bonds, which build up a three-dimensional network.

Related literature

For the chemical and physical properties of nitronyl nitroxides, see: Minguet et al. (2001); Osiecki & Ullman (1968); Shemsi et al. (2007); Wu et al. (2006). For related structures, see: Shimono et al. (2004); Minguet et al. (2001); Tian et al. (2011). For puckering parameters, see Cremer & Pople (1975). For a description of the Cambridge Structural Database, see: Allen (2002).

Experimental

Crystal data

C₂₁H₂₈Cl₂N₃O₆
M_r = 489.36
Orthorhombic, P 2₁ 2₁ 2₁
a = 10.975 (2) Å
b = 12.255 (3) Å
c = 17.741 (4) Å
V = 2386.2 (8) Å³
Z = 4
Mo K radiation
= 0.31 mm^-1
T = 296 K
0.38 × 0.27 × 0.16 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2007) T_min = 0.892, T_max = 0.952
12018 measured reflections
4252 independent reflections
2217 reflections with I > 2(I)
R_int = 0.067

Refinement

R[F² > 2(F²)] = 0.053
wR(F²) = 0.131
S = 1.02
4252 reflections
297 parameters
H-atom parameters constrained
_max = 0.24 e Å^-3
_min = -0.16 e Å^-3
Absolute structure: Flack (1983), 1834 Friedel pairs
Flack parameter: 0.01 (10)

Table 1
Hydrogen-bond geometry (Å, °)

Cg3 is the centroid of the C13-C18 ring.

D-HA	D-H	HA	DA	D-HA
C6-H6BO3ⁱ	0.96	2.54	3.498 (8)	173
C11-H11AO1ⁱⁱ	0.97	2.36	3.281 (6)	159
C21-H21BO2ⁱⁱⁱ	0.96	2.44	3.403 (6)	178
C4-H4ACg3ⁱ	0.96	2.86	3.619 (7)	136
Symmetry codes: (i) $[-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]$ ; (ii) $[x+{\script{1\over 2}}, -y+{\script{3\over 2}}, -z]$ ; (iii) $[-x+2, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: APEX2 (Bruker, 2007); cell refinement: SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEPIII (Burnett & Johnson, 1996) and ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: DN2666 ).

Acknowledgements

We thank the Natural Science Foundation of China (grant Nos. 81001398, 30901883, 20802091, 20802092) for financial support.

References

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Bruker (2007). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
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Cremer, D. & Pople, J. A. (1975). J. Am. Chem. Soc. 97, 1354-1358.
Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565.
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Minguet, M., Amabilino, D. B., Wurst, K. & Veciana, J. (2001). J. Solid State Chem. 159, 440-450.
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