Ethyl 1-benzyl-1,2,3,3a,4,10b-hexa-hydro-pyrrolo-[2',3':3,4]pyrrolo-[1,2-a]benzimidazole-2-carboxyl-ate.

The title mol-ecule, C(22)H(23)N(3)O(2), was obtained via an intra-molecular cyclo-addition of an azomethine ylide and an alkene tethered by a benzimidazole unit. The benzoimidazole unit is essentially planar, with an r.m.s. deviation of 0.0087 Å from the nine constituent atoms. It has a cis fusion of the two pyrrolidine rings as well as a cis ester appendage. The two pyrrolidine rings rings have envelope conformations. The crystal packing is stabilized by aromatic π-π stacking of parallel benzimidazole ring systems, with a centroid-to-centroid distance of 3.518 (6) Å. Weak inter-molecular C-H⋯O contacts may also play a role in the stability of the packing.

Related literature

Polycyclic nitro­gen-containing heterocycles form the basic skeleton of numerous alkaloids and physiologically active compounds, see: Southon & Buckingham (1989 ▶). Conformational studies have been reported for related pyrrolidino[3,4-b]pyrrolidine-2-carboxyl­ates obtained from intra­molecular cyclo­addition of azomethine ylides, see: Cheng et al. (2001 ▶); Meng et al. (2007 ▶). For related literature on the pharmaceutical properties of benzimidazole and pyrrolidine, see: Gudmundsson et al. (2000 ▶); Hamilton & Steiner (1997 ▶). For related literature on the azomethine ylide cycloaddition in similar systems, Pedrosa et al. (2006 ▶); Yang et al. (2006 ▶).

Experimental

Crystal data

C22H23N3O2

M = 361.43

Monoclinic,

a = 9.2498 (5) Å

b = 13.8999 (7) Å

c = 14.2258 (7) Å

β = 90.345 (1)°

V = 1829.00 (16) Å3

Z = 4

Mo Kα radiation

μ = 0.09 mm−1

T = 90 K

0.39 × 0.16 × 0.13 mm

Data collection

Bruker SMART1000 CCD area-detector diffractometer

Absorption correction: numerical (SADABS; Blessing, 1995 ▶; Sheldrick, 2007 ▶) T min = 0.962, T max = 0.989

16147 measured reflections

4194 independent reflections

3080 reflections with I > 2σ(I)

R int = 0.037

Refinement

R[F 2 > 2σ(F 2)] = 0.037

wR(F 2) = 0.095

S = 1.09

4194 reflections

336 parameters

All H-atom parameters refined

Δρmax = 0.37 e Å−3

Δρmin = −0.27 e Å−3

Data collection: SMART (Bruker, 2002 ▶); 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: XP in SHELXTL/PC (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811014292/wn2427sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811014292/wn2427Isup2.hkl

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C22H23N3O2	F(000) = 768
Mr = 361.43	Dx = 1.313 Mg m−3
Monoclinic, P21/n	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2yn	Cell parameters from 7133 reflections
a = 9.2498 (5) Å	θ = 2.6–27.5°
b = 13.8999 (7) Å	µ = 0.09 mm−1
c = 14.2258 (7) Å	T = 90 K
β = 90.345 (1)°	Block, colourless
V = 1829.00 (16) Å3	0.39 × 0.16 × 0.13 mm
Z = 4

Bruker SMART1000 CCD area-detector diffractometer	4194 independent reflections
Radiation source: fine-focus sealed tube	3080 reflections with I > 2σ(I)
graphite	Rint = 0.037
ω and φ scans	θmax = 27.5°, θmin = 2.1°
Absorption correction: numerical (SADABS; Blessing, 1995; Sheldrick, 2007)	h = −12→12
Tmin = 0.962, Tmax = 0.989	k = −18→18
16147 measured reflections	l = −18→18

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.037	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.095	All H-atom parameters refined
S = 1.09	w = 1/[σ2(Fo2) + (0.0417P)2 + 0.3839P] where P = (Fo2 + 2Fc2)/3
4194 reflections	(Δ/σ)max = 0.001
336 parameters	Δρmax = 0.37 e Å−3
0 restraints	Δρmin = −0.27 e Å−3

Experimental. A colourless block with approximate orthogonal dimensions 0.39 × 0.16 × 0.13 mm3 was placed and optically centered on the Bruker SMART1000 CCD system at -183°C. The initial unit cell was indexed using a least-squares analysis of a random set of reflections collected from three series of 0.3° wide ω scans, 10 s per frame, and 25 frames per series that were well distributed in reciprocal space. Four ω-scan data frame series were collected [Mo Kα] with 0.3° wide scans, 30 s per frame and 606, 435, 606, 435 frames collected per series at varying φ angles (φ = 0°, 90°, 180°, 270°), respectively.

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. The crystal to detector distance was 4.123 cm, thus providing a complete sphere of data to 2θmax = 55.06°. A total of 23465 reflections were collected and corrected for Lorentz and polarization effects and absorption using Blessing's method (Blessing, 1995) as incorporated into the program SADABS with 4390 unique. All crystallographic calculations were performed on a personal computer (PC) with a Pentium 3.20 GHz processor and 1 GB of extended memory. The SHELXTL program package was implemented to determine the probable space group and set up the initial files. System symmetry, systematic absences and intensity statistics indicated the centrosymmetric monoclinic non-standard space group P21/n (No. 14). The structure was determined by direct methods with the successful location of a majority of the molecule within the asymmetric unit using the program XS. The structure was refined with XL. The 23465 data collected were merged based upon identical indices yielding 16536 data [R(int) = 0.0245] that were truncated to 2θmax = 55.0° resulting in 16147 data that were further merged during least-squares refinement to 4194 unique data [R(int) = 0.0373]. A single least-squares difference Fourier cycle was required to locate the remaining non-H atoms. All non-H atoms were refined anisotropically. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > σ(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R-factors based on ALL data will be even larger.

	x	y	z	Uiso*/Ueq
C1	0.11370 (13)	0.83406 (9)	0.93388 (9)	0.0171 (3)
H1	0.1841 (15)	0.8014 (10)	0.8905 (10)	0.016 (3)*
N1	−0.03076 (11)	0.79245 (7)	0.92753 (7)	0.0167 (2)
C2A	−0.02373 (14)	0.70281 (9)	0.98214 (9)	0.0168 (3)
H2A	−0.1230 (16)	0.6828 (10)	0.9972 (10)	0.021 (4)*
C2B	0.05845 (13)	0.61970 (9)	0.93939 (9)	0.0164 (3)
N2	0.04725 (11)	0.56851 (8)	0.86159 (7)	0.0188 (2)
C3A	0.15526 (14)	0.49885 (9)	0.87233 (9)	0.0178 (3)
C4	0.19276 (15)	0.42310 (10)	0.81285 (9)	0.0215 (3)
H4	0.1418 (16)	0.4118 (10)	0.7547 (11)	0.024 (4)*
C5	0.30288 (15)	0.36208 (10)	0.84115 (10)	0.0239 (3)
H5	0.3296 (16)	0.3071 (11)	0.8029 (11)	0.024 (4)*
C6	0.37646 (15)	0.37548 (10)	0.92687 (10)	0.0231 (3)
H6	0.4508 (16)	0.3301 (11)	0.9460 (10)	0.025 (4)*
C7	0.34082 (14)	0.44980 (10)	0.98730 (10)	0.0205 (3)
H7	0.3892 (16)	0.4588 (10)	1.0466 (11)	0.023 (4)*
C8A	0.22957 (14)	0.51062 (9)	0.95859 (9)	0.0176 (3)
N8	0.16544 (11)	0.58997 (8)	0.99883 (7)	0.0173 (2)
C9	0.16669 (15)	0.63878 (10)	1.08991 (9)	0.0191 (3)
H9A	0.2688 (16)	0.6555 (10)	1.1086 (10)	0.021 (4)*
H9B	0.1242 (15)	0.5967 (10)	1.1379 (10)	0.022 (4)*
C10A	0.07245 (14)	0.72792 (9)	1.06910 (9)	0.0180 (3)
H10A	0.0137 (14)	0.7435 (9)	1.1239 (10)	0.013 (3)*
C11	0.15928 (15)	0.81681 (10)	1.03687 (9)	0.0193 (3)
H11A	0.2653 (18)	0.8059 (11)	1.0440 (11)	0.029 (4)*
H11B	0.1335 (16)	0.8755 (11)	1.0745 (11)	0.025 (4)*
C12	0.11502 (14)	0.93996 (9)	0.90881 (9)	0.0182 (3)
O12	0.01249 (10)	0.98789 (7)	0.88602 (7)	0.0248 (2)
C13	0.27147 (16)	1.07485 (10)	0.89143 (10)	0.0225 (3)
H13A	0.2190 (16)	1.1145 (11)	0.9382 (11)	0.023 (4)*
H13B	0.2268 (16)	1.0867 (10)	0.8302 (11)	0.022 (4)*
O13	0.25101 (10)	0.97384 (6)	0.91573 (6)	0.0201 (2)
C14	0.43191 (16)	1.09273 (11)	0.89238 (11)	0.0251 (3)
H14A	0.4769 (18)	1.0798 (12)	0.9539 (13)	0.037 (5)*
H14B	0.4516 (18)	1.1615 (13)	0.8784 (11)	0.038 (5)*
H14C	0.4819 (17)	1.0527 (12)	0.8441 (12)	0.035 (4)*
C15	−0.08571 (14)	0.78122 (10)	0.83087 (9)	0.0179 (3)
H15A	−0.0297 (15)	0.7327 (10)	0.7948 (10)	0.018 (4)*
H15B	−0.0739 (15)	0.8460 (11)	0.8007 (10)	0.018 (4)*
C16	−0.24288 (14)	0.75165 (9)	0.82970 (9)	0.0178 (3)
C17	−0.28700 (15)	0.66465 (10)	0.79108 (9)	0.0205 (3)
H17	−0.2161 (17)	0.6209 (11)	0.7651 (11)	0.030 (4)*
C18	−0.43276 (15)	0.63824 (10)	0.79093 (9)	0.0228 (3)
H18	−0.4629 (16)	0.5773 (11)	0.7644 (11)	0.027 (4)*
C19	−0.53434 (15)	0.69891 (11)	0.83067 (9)	0.0232 (3)
H19	−0.6361 (17)	0.6801 (11)	0.8303 (10)	0.024 (4)*
C20	−0.49157 (15)	0.78651 (10)	0.86906 (9)	0.0224 (3)
H20	−0.5630 (16)	0.8300 (11)	0.8959 (10)	0.022 (4)*
C21	−0.34683 (14)	0.81280 (10)	0.86831 (9)	0.0205 (3)
H21	−0.3146 (16)	0.8746 (11)	0.8952 (10)	0.022 (4)*

	U11	U22	U33	U12	U13	U23
C1	0.0135 (6)	0.0187 (6)	0.0189 (6)	0.0002 (5)	0.0018 (5)	−0.0014 (5)
N1	0.0149 (5)	0.0182 (6)	0.0170 (5)	−0.0009 (4)	−0.0002 (4)	0.0011 (4)
C2A	0.0146 (6)	0.0196 (7)	0.0161 (6)	−0.0012 (5)	0.0012 (5)	0.0005 (5)
C2B	0.0145 (6)	0.0186 (6)	0.0162 (6)	−0.0027 (5)	0.0009 (5)	0.0025 (5)
N2	0.0194 (6)	0.0191 (6)	0.0180 (5)	0.0006 (4)	0.0011 (4)	0.0000 (4)
C3A	0.0165 (6)	0.0193 (6)	0.0177 (6)	−0.0013 (5)	0.0030 (5)	0.0042 (5)
C4	0.0244 (7)	0.0236 (7)	0.0164 (7)	−0.0002 (6)	0.0044 (5)	0.0006 (5)
C5	0.0251 (7)	0.0226 (7)	0.0242 (7)	0.0017 (6)	0.0096 (6)	0.0001 (6)
C6	0.0172 (7)	0.0221 (7)	0.0300 (8)	0.0013 (6)	0.0049 (6)	0.0053 (6)
C7	0.0159 (7)	0.0225 (7)	0.0230 (7)	−0.0026 (5)	0.0004 (5)	0.0050 (5)
C8A	0.0173 (6)	0.0179 (6)	0.0177 (6)	−0.0027 (5)	0.0028 (5)	0.0026 (5)
N8	0.0170 (6)	0.0184 (5)	0.0165 (5)	−0.0004 (4)	−0.0005 (4)	0.0013 (4)
C9	0.0207 (7)	0.0208 (7)	0.0157 (6)	−0.0023 (5)	−0.0014 (5)	−0.0002 (5)
C10A	0.0179 (6)	0.0216 (7)	0.0146 (6)	−0.0013 (5)	0.0022 (5)	−0.0014 (5)
C11	0.0194 (7)	0.0182 (7)	0.0204 (7)	−0.0005 (5)	−0.0029 (5)	0.0004 (5)
C12	0.0187 (7)	0.0213 (7)	0.0146 (6)	0.0013 (5)	0.0022 (5)	−0.0021 (5)
O12	0.0232 (5)	0.0226 (5)	0.0284 (5)	0.0044 (4)	−0.0022 (4)	0.0015 (4)
C13	0.0289 (8)	0.0154 (7)	0.0233 (7)	−0.0024 (6)	−0.0026 (6)	0.0023 (5)
O13	0.0207 (5)	0.0161 (5)	0.0235 (5)	−0.0020 (4)	0.0003 (4)	0.0015 (4)
C14	0.0297 (8)	0.0199 (7)	0.0257 (8)	−0.0066 (6)	−0.0002 (6)	0.0008 (6)
C15	0.0159 (6)	0.0221 (7)	0.0156 (6)	0.0008 (5)	0.0010 (5)	0.0000 (5)
C16	0.0173 (7)	0.0229 (7)	0.0130 (6)	0.0012 (5)	−0.0013 (5)	0.0031 (5)
C17	0.0201 (7)	0.0248 (7)	0.0164 (6)	0.0032 (6)	−0.0009 (5)	0.0009 (5)
C18	0.0242 (7)	0.0247 (7)	0.0193 (7)	−0.0027 (6)	−0.0052 (5)	0.0014 (6)
C19	0.0165 (7)	0.0322 (8)	0.0209 (7)	−0.0019 (6)	−0.0033 (5)	0.0043 (6)
C20	0.0171 (7)	0.0305 (8)	0.0195 (7)	0.0047 (6)	−0.0005 (5)	0.0010 (6)
C21	0.0206 (7)	0.0232 (7)	0.0177 (6)	0.0010 (6)	−0.0011 (5)	−0.0008 (5)

C1—N1	1.4582 (16)	C10A—C11	1.5448 (18)
C1—C12	1.5147 (18)	C10A—H10A	0.977 (14)
C1—C11	1.5409 (18)	C11—H11A	0.997 (16)
C1—H1	1.008 (14)	C11—H11B	1.005 (15)
N1—C2A	1.4696 (16)	C12—O12	1.2019 (16)
N1—C15	1.4714 (16)	C12—O13	1.3462 (15)
C2A—C2B	1.5126 (18)	C13—O13	1.4584 (16)
C2A—C10A	1.5590 (17)	C13—C14	1.505 (2)
C2A—H2A	0.984 (15)	C13—H13A	0.993 (15)
C2B—N2	1.3193 (16)	C13—H13B	0.976 (15)
C2B—N8	1.3620 (16)	C14—H14A	0.983 (18)
N2—C3A	1.3990 (17)	C14—H14B	0.994 (18)
C3A—C4	1.3959 (18)	C14—H14C	0.999 (17)
C3A—C8A	1.4125 (18)	C15—C16	1.5108 (18)
C4—C5	1.383 (2)	C15—H15A	0.994 (14)
C4—H4	0.963 (16)	C15—H15B	1.004 (15)
C5—C6	1.405 (2)	C16—C17	1.3885 (19)
C5—H5	0.971 (15)	C16—C21	1.3982 (18)
C6—C7	1.385 (2)	C17—C18	1.3973 (19)
C6—H6	0.971 (16)	C17—H17	0.969 (16)
C7—C8A	1.3912 (18)	C18—C19	1.386 (2)
C7—H7	0.961 (15)	C18—H18	0.967 (16)
C8A—N8	1.3785 (16)	C19—C20	1.391 (2)
N8—C9	1.4625 (16)	C19—H19	0.977 (15)
C9—C10A	1.5425 (18)	C20—C21	1.3879 (19)
C9—H9A	1.006 (15)	C20—H20	0.975 (15)
C9—H9B	0.983 (15)	C21—H21	0.986 (15)
N1—C1—C12	112.30 (10)	C9—C10A—H10A	110.0 (8)
N1—C1—C11	104.04 (10)	C11—C10A—H10A	110.6 (8)
C12—C1—C11	111.87 (11)	C2A—C10A—H10A	111.4 (8)
N1—C1—H1	112.2 (8)	C1—C11—C10A	105.48 (10)
C12—C1—H1	106.7 (8)	C1—C11—H11A	112.6 (9)
C11—C1—H1	109.7 (8)	C10A—C11—H11A	111.2 (9)
C1—N1—C2A	105.42 (10)	C1—C11—H11B	108.4 (9)
C1—N1—C15	114.29 (10)	C10A—C11—H11B	111.5 (9)
C2A—N1—C15	114.70 (10)	H11A—C11—H11B	107.8 (12)
N1—C2A—C2B	117.12 (10)	O12—C12—O13	124.14 (12)
N1—C2A—C10A	104.65 (10)	O12—C12—C1	126.49 (12)
C2B—C2A—C10A	101.79 (10)	O13—C12—C1	109.37 (11)
N1—C2A—H2A	108.5 (8)	O13—C13—C14	106.64 (11)
C2B—C2A—H2A	110.1 (9)	O13—C13—H13A	108.1 (9)
C10A—C2A—H2A	114.8 (8)	C14—C13—H13A	112.9 (9)
N2—C2B—N8	114.23 (11)	O13—C13—H13B	108.6 (9)
N2—C2B—C2A	135.40 (12)	C14—C13—H13B	113.1 (9)
N8—C2B—C2A	110.31 (11)	H13A—C13—H13B	107.4 (12)
C2B—N2—C3A	103.25 (11)	C12—O13—C13	116.23 (10)
C4—C3A—N2	129.48 (12)	C13—C14—H14A	112.9 (10)
C4—C3A—C8A	119.52 (12)	C13—C14—H14B	109.8 (10)
N2—C3A—C8A	110.99 (11)	H14A—C14—H14B	106.1 (14)
C5—C4—C3A	118.11 (13)	C13—C14—H14C	111.3 (10)
C5—C4—H4	120.4 (9)	H14A—C14—H14C	108.3 (14)
C3A—C4—H4	121.5 (9)	H14B—C14—H14C	108.2 (13)
C4—C5—C6	121.55 (13)	N1—C15—C16	111.48 (10)
C4—C5—H5	120.6 (9)	N1—C15—H15A	112.1 (8)
C6—C5—H5	117.8 (9)	C16—C15—H15A	108.3 (8)
C7—C6—C5	121.44 (13)	N1—C15—H15B	105.5 (8)
C7—C6—H6	118.8 (9)	C16—C15—H15B	110.3 (8)
C5—C6—H6	119.7 (9)	H15A—C15—H15B	109.2 (11)
C6—C7—C8A	116.70 (13)	C17—C16—C21	118.93 (12)
C6—C7—H7	122.1 (9)	C17—C16—C15	121.45 (12)
C8A—C7—H7	121.2 (9)	C21—C16—C15	119.62 (12)
N8—C8A—C7	133.13 (12)	C16—C17—C18	120.71 (13)
N8—C8A—C3A	104.19 (11)	C16—C17—H17	119.9 (9)
C7—C8A—C3A	122.68 (12)	C18—C17—H17	119.3 (9)
C2B—N8—C8A	107.32 (10)	C19—C18—C17	119.74 (13)
C2B—N8—C9	114.28 (11)	C19—C18—H18	119.8 (9)
C8A—N8—C9	137.56 (11)	C17—C18—H18	120.4 (9)
N8—C9—C10A	101.61 (10)	C18—C19—C20	120.07 (13)
N8—C9—H9A	110.0 (8)	C18—C19—H19	119.4 (9)
C10A—C9—H9A	113.2 (8)	C20—C19—H19	120.6 (9)
N8—C9—H9B	109.8 (9)	C21—C20—C19	119.96 (13)
C10A—C9—H9B	112.6 (9)	C21—C20—H20	119.7 (9)
H9A—C9—H9B	109.4 (12)	C19—C20—H20	120.3 (9)
C9—C10A—C11	113.90 (11)	C20—C21—C16	120.58 (13)
C9—C10A—C2A	106.95 (10)	C20—C21—H21	121.1 (9)
C11—C10A—C2A	103.81 (10)	C16—C21—H21	118.4 (9)

D—H···A	D—H	H···A	D···A	D—H···A
C11—H11B···O12i	1.005 (15)	2.399 (15)	3.3344 (17)	154.5 (12)
C18—H18···O12ii	0.968 (15)	2.514 (16)	3.3505 (17)	144.6 (12)

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C11—H11B⋯O12i	1.005 (15)	2.399 (15)	3.3344 (17)	154.5 (12)
C18—H18⋯O12ii	0.968 (15)	2.514 (16)	3.3505 (17)	144.6 (12)

Symmetry codes: (i) ; (ii) .