organic compounds
Dimethyl 9-benzyl-3-cyano-9H-pyrrolo[1,2-a]benzimidazole-1,2-dicarboxylate
aDepartment of Applied Chemistry, Nanjing Normal University, Nanjing 210097, People's Republic of China
*Correspondence e-mail: wang.bingxiang@yahoo.com
The title compound, C22H17N3O4, was prepared through 1,3-dipolar cycloaddition: the dihedral angle between the benzimidazole and benzene rings is 80.93 (6)°. The is stabilized by weak π–π interactions between the planar pyrrolobenzimidazole rings (r.m.s. deviation = 0.0293 Å) of neighbouring molecules, forming chains along the c axis. The perpendicular distance is 3.47 (2) Å and the centroid–centroid distances are in the range of 3.590 (3)–3.944 (3) Å.
Related literature
For the use of 1,3-dipolar cycloaddition reactions of et al. (2007). For the applications of nitrogen heteroaromatic ring systems, see: Ansari & Lal (2009); Shen et al. (2006, 2008); Zhang et al. (2009). For the synthesis, see: Wang et al. (2000).
in the construction of five-membered nitrogen heteroaromatic ring systems, see: BerryExperimental
Crystal data
|
Data collection: SMART (Bruker, 2000); cell SAINT (Bruker, 2000); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.
Supporting information
10.1107/S1600536809048867/zq2016sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536809048867/zq2016Isup2.hkl
Dimethyl 4-benzyl-1-cyano-4H-pyrrolo[1,2-a] benzimidazole-2,3-dicarboxylate was prepared through 1,3-dipolar
according to a procedure described in the literature (Wang et al., 2000). Colorless crystals were obtained by recrystallization from a dichloromethane solution at room temperature.The H atoms were positioned geometrically and refined using a riding model (including
about the ethanol C—C bond), with C—H = 0.93–0.97 Å and with Uiso(H) = 1.2 (1.5 for methyl groups) times Ueq(C).Data collection: SMART (Bruker, 2000); cell
SAINT (Bruker, 2000); data reduction: SAINT (Bruker, 2000); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C22H17N3O4 | F(000) = 808 |
Mr = 387.39 | Dx = 1.376 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 1791 reflections |
a = 9.8681 (15) Å | θ = 2.6–25.2° |
b = 24.766 (2) Å | µ = 0.10 mm−1 |
c = 7.6551 (11) Å | T = 291 K |
β = 91.973 (3)° | Block, colorless |
V = 1869.7 (4) Å3 | 0.26 × 0.22 × 0.20 mm |
Z = 4 |
Bruker SMART APEX CCD diffractometer | 3615 independent reflections |
Radiation source: sealed tube | 2699 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.057 |
phi and ω scans | θmax = 26.0°, θmin = 1.6° |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | h = −12→12 |
Tmin = 0.97, Tmax = 0.98 | k = −26→30 |
13898 measured reflections | l = −9→9 |
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)] = 0.056 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.125 | H-atom parameters constrained |
S = 1.03 | w = 1/[σ2(Fo2) + (0.05P)2 + 0.66P] where P = (Fo2 + 2Fc2)/3 |
3615 reflections | (Δ/σ)max < 0.001 |
264 parameters | Δρmax = 0.19 e Å−3 |
0 restraints | Δρmin = −0.19 e Å−3 |
C22H17N3O4 | V = 1869.7 (4) Å3 |
Mr = 387.39 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 9.8681 (15) Å | µ = 0.10 mm−1 |
b = 24.766 (2) Å | T = 291 K |
c = 7.6551 (11) Å | 0.26 × 0.22 × 0.20 mm |
β = 91.973 (3)° |
Bruker SMART APEX CCD diffractometer | 3615 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2000) | 2699 reflections with I > 2σ(I) |
Tmin = 0.97, Tmax = 0.98 | Rint = 0.057 |
13898 measured reflections |
R[F2 > 2σ(F2)] = 0.056 | 0 restraints |
wR(F2) = 0.125 | H-atom parameters constrained |
S = 1.03 | Δρmax = 0.19 e Å−3 |
3615 reflections | Δρmin = −0.19 e Å−3 |
264 parameters |
Experimental. 1H-NMR (CDCl3, 400 MHz) δ: 3.81 (s, 3H, –COOCH3), 4.00 (s, 3H, –COOCH3), 5.92 (s, 2H, –CH2Ph), 7.20–7.41 (m, 8H, ArH), 8.07 (d, 1H, J = 7.9 Hz, ArH) |
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. Least-squares planes (x,y,z in crystal coordinates) and deviations from them (* indicates atom used to define plane) -0.0001(0.0049) x + 11.1526(0.0083)y + 6.8309(0.0017) z = 16.2473 (0.0105) * 0.0370 (0.0017) C1 * 0.0187 (0.0017) C2 * -0.0329 (0.0017) C3 * -0.0312 (0.0019) C4 * -0.0132 (0.0017) C5 * 0.0115 (0.0017) C6 * 0.0056 (0.0017) C7 * -0.0396 (0.0016) C8 * -0.0420 (0.0016) C9 * 0.0128 (0.0016) C10 * 0.0392 (0.0015) N1 * 0.0341 (0.0015) N2 Rms deviation of fitted atoms = 0.0293 7.9901(0.0063)x + 10.7417(0.0233)y - 3.2379(0.0071)z = 12.8495 (0.0190) Angle to previous plane (with approximate e.s.d.) = 80.93 (0.06) * 0.0109 (0.0016) C13 * -0.0131 (0.0017) C14 * 0.0058 (0.0018) C15 * 0.0036 (0.0019) C16 * -0.0055 (0.0019) C17 * -0.0016 (0.0017) C18 Rms deviation of fitted atoms = 0.0078 |
Refinement. 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 | 1.0019 (2) | 1.00932 (8) | 0.7360 (3) | 0.0272 (4) | |
C2 | 1.0476 (2) | 1.05587 (9) | 0.6574 (3) | 0.0342 (5) | |
H2 | 1.1394 | 1.0634 | 0.6481 | 0.041* | |
C3 | 0.9480 (3) | 1.09034 (10) | 0.5935 (3) | 0.0403 (6) | |
H3 | 0.9727 | 1.1219 | 0.5367 | 0.048* | |
C4 | 0.8095 (2) | 1.07867 (9) | 0.6128 (3) | 0.0387 (6) | |
H4 | 0.7450 | 1.1033 | 0.5710 | 0.046* | |
C5 | 0.7662 (2) | 1.03148 (10) | 0.6925 (3) | 0.0359 (5) | |
H5 | 0.6746 | 1.0239 | 0.7042 | 0.043* | |
C6 | 0.8651 (2) | 0.99690 (9) | 0.7526 (3) | 0.0283 (5) | |
C7 | 0.9829 (2) | 0.92732 (8) | 0.8653 (3) | 0.0252 (4) | |
C8 | 1.0572 (2) | 0.88306 (9) | 0.9310 (3) | 0.0283 (5) | |
C9 | 1.1957 (2) | 0.89723 (9) | 0.9075 (3) | 0.0301 (5) | |
C10 | 1.2040 (2) | 0.94775 (9) | 0.8330 (3) | 0.0288 (5) | |
C11 | 1.3184 (2) | 0.97791 (9) | 0.7903 (3) | 0.0333 (5) | |
C12 | 0.7257 (2) | 0.91558 (10) | 0.8516 (3) | 0.0326 (5) | |
H12A | 0.6509 | 0.9402 | 0.8692 | 0.039* | |
H12B | 0.7325 | 0.8913 | 0.9509 | 0.039* | |
C13 | 0.69949 (19) | 0.88336 (9) | 0.6848 (3) | 0.0292 (5) | |
C14 | 0.6168 (2) | 0.90361 (10) | 0.5555 (3) | 0.0394 (6) | |
H14 | 0.5747 | 0.9368 | 0.5706 | 0.047* | |
C15 | 0.5946 (3) | 0.87514 (11) | 0.4004 (3) | 0.0463 (7) | |
H15 | 0.5403 | 0.8898 | 0.3108 | 0.056* | |
C16 | 0.6539 (3) | 0.82453 (12) | 0.3795 (3) | 0.0493 (7) | |
H16 | 0.6382 | 0.8055 | 0.2761 | 0.059* | |
C17 | 0.7340 (3) | 0.80288 (12) | 0.5082 (3) | 0.0466 (6) | |
H17 | 0.7729 | 0.7690 | 0.4944 | 0.056* | |
C18 | 0.7576 (2) | 0.83240 (10) | 0.6629 (3) | 0.0411 (6) | |
H18 | 0.8125 | 0.8179 | 0.7521 | 0.049* | |
C19 | 1.0032 (2) | 0.83746 (9) | 1.0316 (3) | 0.0336 (5) | |
C20 | 1.0629 (3) | 0.76423 (12) | 1.2133 (4) | 0.0577 (8) | |
H20A | 1.0048 | 0.7778 | 1.3013 | 0.087* | |
H20B | 1.1420 | 0.7482 | 1.2682 | 0.087* | |
H20C | 1.0150 | 0.7376 | 1.1441 | 0.087* | |
C21 | 1.3202 (2) | 0.86405 (10) | 0.9391 (3) | 0.0376 (5) | |
C22 | 1.4343 (3) | 0.78357 (12) | 0.8747 (4) | 0.0528 (7) | |
H22A | 1.5076 | 0.7961 | 0.8061 | 0.079* | |
H22B | 1.4102 | 0.7475 | 0.8400 | 0.079* | |
H22C | 1.4619 | 0.7838 | 0.9962 | 0.079* | |
N1 | 1.07206 (16) | 0.96508 (7) | 0.8086 (2) | 0.0243 (4) | |
N2 | 0.85368 (17) | 0.94658 (7) | 0.8381 (2) | 0.0278 (4) | |
N3 | 1.41453 (19) | 1.00265 (9) | 0.7614 (3) | 0.0411 (5) | |
O1 | 1.10343 (16) | 0.80841 (7) | 1.1015 (2) | 0.0403 (4) | |
O2 | 0.88636 (17) | 0.82715 (7) | 1.0552 (2) | 0.0449 (5) | |
O3 | 1.31742 (17) | 0.81903 (7) | 0.8471 (2) | 0.0451 (5) | |
O4 | 1.4114 (2) | 0.87751 (9) | 1.0281 (3) | 0.0648 (6) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0323 (11) | 0.0244 (11) | 0.0247 (10) | −0.0022 (9) | −0.0037 (8) | −0.0041 (8) |
C2 | 0.0466 (13) | 0.0273 (12) | 0.0285 (11) | −0.0057 (10) | 0.0002 (10) | −0.0019 (9) |
C3 | 0.0513 (15) | 0.0310 (13) | 0.0385 (13) | 0.0007 (11) | 0.0013 (11) | −0.0045 (10) |
C4 | 0.0433 (14) | 0.0249 (12) | 0.0473 (14) | 0.0040 (10) | −0.0059 (11) | −0.0014 (10) |
C5 | 0.0323 (12) | 0.0352 (13) | 0.0399 (13) | 0.0041 (10) | −0.0055 (10) | −0.0037 (10) |
C6 | 0.0274 (10) | 0.0230 (11) | 0.0343 (11) | 0.0022 (9) | −0.0014 (9) | −0.0041 (9) |
C7 | 0.0232 (10) | 0.0269 (11) | 0.0254 (10) | −0.0068 (8) | 0.0006 (8) | −0.0034 (8) |
C8 | 0.0264 (10) | 0.0329 (12) | 0.0257 (10) | −0.0025 (9) | 0.0022 (8) | −0.0034 (9) |
C9 | 0.0301 (11) | 0.0342 (13) | 0.0255 (10) | −0.0010 (9) | −0.0045 (9) | −0.0033 (9) |
C10 | 0.0238 (10) | 0.0337 (13) | 0.0284 (10) | 0.0024 (9) | −0.0040 (8) | −0.0013 (9) |
C11 | 0.0260 (11) | 0.0289 (12) | 0.0448 (13) | 0.0028 (9) | −0.0003 (10) | −0.0014 (10) |
C12 | 0.0189 (10) | 0.0365 (13) | 0.0428 (13) | −0.0071 (9) | 0.0074 (9) | −0.0026 (10) |
C13 | 0.0175 (9) | 0.0341 (12) | 0.0361 (12) | −0.0056 (9) | 0.0054 (8) | 0.0021 (9) |
C14 | 0.0381 (13) | 0.0348 (13) | 0.0444 (13) | −0.0044 (10) | −0.0116 (10) | −0.0010 (11) |
C15 | 0.0522 (15) | 0.0540 (17) | 0.0316 (13) | −0.0098 (13) | −0.0143 (11) | 0.0006 (11) |
C16 | 0.0535 (16) | 0.0536 (17) | 0.0406 (14) | −0.0132 (13) | −0.0033 (12) | −0.0178 (12) |
C17 | 0.0485 (15) | 0.0460 (15) | 0.0457 (15) | −0.0021 (12) | 0.0038 (12) | −0.0133 (12) |
C18 | 0.0398 (13) | 0.0361 (14) | 0.0466 (14) | 0.0050 (11) | −0.0073 (11) | −0.0077 (11) |
C19 | 0.0377 (13) | 0.0303 (13) | 0.0321 (12) | 0.0005 (10) | −0.0074 (10) | −0.0015 (9) |
C20 | 0.076 (2) | 0.0544 (18) | 0.0425 (15) | 0.0009 (15) | 0.0044 (14) | 0.0349 (13) |
C21 | 0.0348 (12) | 0.0373 (14) | 0.0403 (13) | 0.0018 (10) | −0.0031 (10) | 0.0009 (11) |
C22 | 0.0480 (15) | 0.0571 (18) | 0.0535 (16) | 0.0282 (13) | 0.0064 (13) | −0.0133 (13) |
N1 | 0.0211 (8) | 0.0270 (9) | 0.0249 (9) | −0.0030 (7) | 0.0014 (7) | −0.0028 (7) |
N2 | 0.0221 (8) | 0.0295 (10) | 0.0319 (9) | −0.0045 (7) | 0.0000 (7) | −0.0004 (7) |
N3 | 0.0303 (10) | 0.0528 (14) | 0.0404 (11) | −0.0052 (10) | 0.0049 (8) | 0.0129 (10) |
O1 | 0.0418 (9) | 0.0435 (10) | 0.0356 (9) | 0.0077 (8) | 0.0030 (7) | 0.0184 (7) |
O2 | 0.0395 (10) | 0.0547 (11) | 0.0399 (9) | −0.0098 (8) | −0.0049 (7) | 0.0225 (8) |
O3 | 0.0467 (10) | 0.0461 (11) | 0.0422 (9) | 0.0157 (8) | −0.0041 (8) | −0.0152 (8) |
O4 | 0.0576 (12) | 0.0899 (16) | 0.0452 (11) | 0.0140 (11) | −0.0211 (10) | −0.0184 (11) |
C1—C2 | 1.384 (3) | C12—H12B | 0.9700 |
C1—C6 | 1.394 (3) | C13—C14 | 1.357 (3) |
C1—N1 | 1.401 (3) | C13—C18 | 1.398 (3) |
C2—C3 | 1.379 (3) | C14—C15 | 1.392 (3) |
C2—H2 | 0.9300 | C14—H14 | 0.9300 |
C3—C4 | 1.410 (4) | C15—C16 | 1.395 (4) |
C3—H3 | 0.9300 | C15—H15 | 0.9300 |
C4—C5 | 1.392 (3) | C16—C17 | 1.352 (4) |
C4—H4 | 0.9300 | C16—H16 | 0.9300 |
C5—C6 | 1.366 (3) | C17—C18 | 1.405 (3) |
C5—H5 | 0.9300 | C17—H17 | 0.9300 |
C6—N2 | 1.414 (3) | C18—H18 | 0.9300 |
C7—N1 | 1.365 (3) | C19—O2 | 1.201 (3) |
C7—N2 | 1.371 (3) | C19—O1 | 1.321 (3) |
C7—C8 | 1.402 (3) | C20—O1 | 1.454 (3) |
C8—C9 | 1.429 (3) | C20—H20A | 0.9600 |
C8—C19 | 1.477 (3) | C20—H20B | 0.9600 |
C9—C10 | 1.378 (3) | C20—H20C | 0.9600 |
C9—C21 | 1.491 (3) | C21—O4 | 1.159 (3) |
C10—N1 | 1.378 (3) | C21—O3 | 1.318 (3) |
C10—C11 | 1.401 (3) | C22—O3 | 1.459 (3) |
C11—N3 | 1.157 (3) | C22—H22A | 0.9600 |
C12—N2 | 1.485 (3) | C22—H22B | 0.9600 |
C12—C13 | 1.520 (3) | C22—H22C | 0.9600 |
C12—H12A | 0.9700 | ||
C2—C1—C6 | 123.7 (2) | C13—C14—H14 | 119.7 |
C2—C1—N1 | 131.3 (2) | C15—C14—H14 | 119.7 |
C6—C1—N1 | 104.97 (17) | C14—C15—C16 | 119.9 (2) |
C3—C2—C1 | 115.5 (2) | C14—C15—H15 | 120.0 |
C3—C2—H2 | 122.2 | C16—C15—H15 | 120.0 |
C1—C2—H2 | 122.2 | C17—C16—C15 | 120.7 (2) |
C2—C3—C4 | 121.2 (2) | C17—C16—H16 | 119.7 |
C2—C3—H3 | 119.4 | C15—C16—H16 | 119.7 |
C4—C3—H3 | 119.4 | C16—C17—C18 | 118.9 (3) |
C5—C4—C3 | 122.1 (2) | C16—C17—H17 | 120.5 |
C5—C4—H4 | 118.9 | C18—C17—H17 | 120.5 |
C3—C4—H4 | 118.9 | C13—C18—C17 | 121.0 (2) |
C6—C5—C4 | 116.5 (2) | C13—C18—H18 | 119.5 |
C6—C5—H5 | 121.7 | C17—C18—H18 | 119.5 |
C4—C5—H5 | 121.7 | O2—C19—O1 | 122.2 (2) |
C5—C6—C1 | 120.9 (2) | O2—C19—C8 | 127.4 (2) |
C5—C6—N2 | 129.9 (2) | O1—C19—C8 | 110.4 (2) |
C1—C6—N2 | 109.22 (17) | O1—C20—H20A | 109.5 |
N1—C7—N2 | 108.65 (18) | O1—C20—H20B | 109.5 |
N1—C7—C8 | 108.36 (18) | H20A—C20—H20B | 109.5 |
N2—C7—C8 | 142.99 (19) | O1—C20—H20C | 109.5 |
C7—C8—C9 | 104.67 (19) | H20A—C20—H20C | 109.5 |
C7—C8—C19 | 126.24 (19) | H20B—C20—H20C | 109.5 |
C9—C8—C19 | 128.1 (2) | O4—C21—O3 | 124.0 (2) |
C10—C9—C8 | 110.22 (19) | O4—C21—C9 | 123.7 (2) |
C10—C9—C21 | 120.5 (2) | O3—C21—C9 | 112.17 (19) |
C8—C9—C21 | 129.1 (2) | O3—C22—H22A | 109.5 |
N1—C10—C9 | 105.65 (18) | O3—C22—H22B | 109.5 |
N1—C10—C11 | 124.6 (2) | H22A—C22—H22B | 109.5 |
C9—C10—C11 | 129.77 (19) | O3—C22—H22C | 109.5 |
N3—C11—C10 | 177.5 (2) | H22A—C22—H22C | 109.5 |
N2—C12—C13 | 109.47 (17) | H22B—C22—H22C | 109.5 |
N2—C12—H12A | 109.8 | C7—N1—C10 | 111.09 (17) |
C13—C12—H12A | 109.8 | C7—N1—C1 | 110.29 (17) |
N2—C12—H12B | 109.8 | C10—N1—C1 | 138.55 (18) |
C13—C12—H12B | 109.8 | C7—N2—C6 | 106.77 (16) |
H12A—C12—H12B | 108.2 | C7—N2—C12 | 126.79 (18) |
C14—C13—C18 | 119.0 (2) | C6—N2—C12 | 124.71 (17) |
C14—C13—C12 | 120.0 (2) | C19—O1—C20 | 115.5 (2) |
C18—C13—C12 | 121.1 (2) | C21—O3—C22 | 115.44 (19) |
C13—C14—C15 | 120.6 (2) |
Experimental details
Crystal data | |
Chemical formula | C22H17N3O4 |
Mr | 387.39 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 291 |
a, b, c (Å) | 9.8681 (15), 24.766 (2), 7.6551 (11) |
β (°) | 91.973 (3) |
V (Å3) | 1869.7 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.26 × 0.22 × 0.20 |
Data collection | |
Diffractometer | Bruker SMART APEX CCD diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2000) |
Tmin, Tmax | 0.97, 0.98 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 13898, 3615, 2699 |
Rint | 0.057 |
(sin θ/λ)max (Å−1) | 0.617 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.056, 0.125, 1.03 |
No. of reflections | 3615 |
No. of parameters | 264 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.19, −0.19 |
Computer programs: SMART (Bruker, 2000), SAINT (Bruker, 2000), SHELXTL (Sheldrick, 2008).
C1—N1 | 1.401 (3) | C10—N1 | 1.378 (3) |
C6—N2 | 1.414 (3) | C11—N3 | 1.157 (3) |
C7—N1 | 1.365 (3) | C12—N2 | 1.485 (3) |
C7—N2 | 1.371 (3) | ||
C2—C1—N1 | 131.3 (2) | N1—C10—C11 | 124.6 (2) |
C6—C1—N1 | 104.97 (17) | N3—C11—C10 | 177.5 (2) |
N1—C7—N2 | 108.65 (18) | N2—C12—C13 | 109.47 (17) |
N1—C7—C8 | 108.36 (18) | N2—C12—H12A | 109.8 |
N2—C7—C8 | 142.99 (19) | N2—C12—H12B | 109.8 |
N1—C10—C9 | 105.65 (18) |
Acknowledgements
We thank the Natural Science Foundation of Jiangsu Province of China (grant No. BK2008435) and the Natural Science Foundation of the Jiangsu Higher Education Institutions of China (grant No. 07KJD150101) for financial support.
References
Ansari, K. F. & Lal, C. (2009). Eur. J. Med. Chem. 44, 2294–2299. Web of Science CrossRef PubMed CAS Google Scholar
Berry, C. R., Zificsak, C. A., Gibbs, A. C. & Hlasta, D. J. (2007). Org. Lett. 9, 4099–4102. Web of Science CrossRef PubMed CAS Google Scholar
Bruker (2000). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Shen, Y.-M., Wang, B.-X., Feng, Y.-Y., Shen, Z.-Y., Shen, J., Li, C. & Hu, H.-W. (2006). Chem. J. Chin. Univ. 27, 651–653. CAS Google Scholar
Shen, Z.-Y., Wang, B.-X., Shen, J. & Hu, H.-W. (2008). Chem. J. Chin. Univ. 29, 916–918. CAS Google Scholar
Wang, B.-X., Hu, J.-X., Zhang, X.-C., Hu, Y.-F. & Hu, H.-W. (2000). J. Heterocycl. Chem. 37, 1533–1537. CrossRef CAS Google Scholar
Zhang, D.-T., Wang, Z.-H., Xu, W.-R., Sun, F.-G., Tang, L.-D. & Wang, J.-W. (2009). Eur. J. Med. Chem. 44, 2202–2210. Web of Science CrossRef PubMed CAS Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
1,3-Dipolar cycloadditions of azomethine ylides are one of the most powerful methods for the construction of five membered nitrogen heteroaromatic ring systems, both inter and intramolecularly (Berry et al., 2007). Nitrogen heteroaromatic ring systems, such as benzimidazoles and indolizines, can be utilized as not only a wide variety of biologically active and medicinally significant compounds (Zhang et al., 2009; Ansari et al., 2009), but also organic fluorescence probes (Shen et al., 2006; Shen et al., 2008). In our continuing studies in organic fluorescence probes, we synthesized the title compound (I), dimethyl 4-benzyl-1-cyano-4H-pyrrolo[1, 2 - a] benzimidazole-2,3-dicarboxylate, C22H17N3O4.
The crystal structure of (I) reveals that all the bond lengths and angles have normal values. There is one title compound molecule per asymmetric unit. Each molecule contains one pyrrolo-benzimidazole ring A and one benzyl ring B (Fig 1). The rings A and B are almost perpendicular, making a dihedral angle of 80.93 (6)°.
In the crystal structure there are weak π–π interactions between the planar pyrrolo-benzimidazole rings (r.m.s. deviation of 0.0293 Å) of neighbouring molecules. The perpendicular distance is 3.47 (2) Å and the distances Cg1—Cg2i and Cg2—Cg2iii are 3.590 (3) and 3.944 (3) Å, respectively. (Cg1 is the center of ring C7/C8/C9/C10/N1 and Cg2 is the center of ring C1/C2/C3/C4/C5/C6; i: 2 - x, 2 - y, 2 - z; iii: 2 - x, 2 - y, 1 - z). Through the π–π interactions one-dimensional chains are formed along c axis.