organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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1-Ethyl-1H,6H-pyrrolo[2,3-c]azepine-4,8(5H,7H)-dione

aDepartment of Chemistry, Jinan University, Guangzhou, Guangdong 510632, People's Republic of China
*Correspondence e-mail: xczeng@126.com

(Received 2 July 2009; accepted 12 July 2009; online 18 July 2009)

The title compound, C10H12N2O2, was synthesized by cyclization of 3-(1-ethyl­pyrrole-2-carboxamido)propanoic acid in the presence of polyphospho­ric acid and diphospho­rus pentoxide. In the crystal structure, adjacent mol­ecules are linked by N—H⋯O hydrogen bonds, forming chains extending along the b axis.

Related literature

For pyrroles sourced from marine organisms, see: Liu et al. (2005[Liu, J. F., Guo, S. P. & Jiang, B. (2005). Chin. J. Org. Chem. 25, 788-799.]). For the bioactivity of pyrrole derivatives, see: Banwell et al. (2006[Banwell, M. G., Hamel, E., Hockless, D. C. R., Verdier-Pinard, P., Willis, A. C. & Wong, D. J. (2006). Bioorg. Med. Chem. 14, 4627-4638.]); Sosa et al. (2002[Sosa, A. C. B., Yakushijin, K. & Horne, D. A. (2002). J. Org. Chem. 67, 4498-4500.]). For related structures, see: Zeng (2006[Zeng, X.-C. (2006). Acta Cryst. E62, o5505-o5507.]); Zeng et al. (2005[Zeng, X.-C., Xu, S.-H., Gu, J. & Deng, D.-S. (2005). Acta Cryst. E61, o795-o796.]).

[Scheme 1]

Experimental

Crystal data
  • C10H12N2O2

  • Mr = 192.22

  • Monoclinic, P 21 /c

  • a = 11.703 (2) Å

  • b = 7.7863 (13) Å

  • c = 11.0004 (19) Å

  • β = 113.878 (3)°

  • V = 916.6 (3) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 0.10 mm−1

  • T = 173 K

  • 0.46 × 0.45 × 0.30 mm

Data collection
  • Bruker SMART 1K CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Sheldrick, 1996[Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.]) Tmin = 0.956, Tmax = 0.971

  • 4523 measured reflections

  • 1984 independent reflections

  • 1661 reflections with I > 2σ(I)

  • Rint = 0.021

Refinement
  • R[F2 > 2σ(F2)] = 0.037

  • wR(F2) = 0.104

  • S = 1.07

  • 1984 reflections

  • 128 parameters

  • H-atom parameters constrained

  • Δρmax = 0.28 e Å−3

  • Δρmin = −0.21 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N2—H2A⋯O1i 0.88 2.12 2.9043 (14) 148
Symmetry code: (i) [-x+1, y+{\script{1\over 2}}, -z+{\script{1\over 2}}].

Data collection: SMART (Bruker,1999[Bruker (1999). SMART and SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT-Plus (Bruker, 1999[Bruker (1999). SMART and SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

Pyrrole derivatives are well known in many marine organisms (Liu et al., 2005), some show important bioactivities, such as antitumor activity (Banwell et al., 2006) and protein kinase inhibiting activity (Sosa et al., 2002). This is the reason they have attracted our interest. This study is related to our previous structural investigations of 1-Methyl-6,7-dihydropyrrolo[2,3-c]azepine-4,8(1H,5H)-dione (Zeng et al.,2005) and 3-bromo-1-methyl-6,7- dihydropyrrolo[2,3-c]azepine-4,8(1H,5H)-dione (Zeng, 2006). In the crystal structure, molecules of the title compound are linked through N2—H2A···O1 hydrogen bonds to form chains extending to the b axis (shown in Fig. 2).

Related literature top

For pyrroles sourced from marine organisms, see: Liu et al. (2005). For the bioactivity of pyrrole derivatives, see: Banwell et al. (2006); Sosa et al. (2002). For related structures, see: Zeng (2006); Zeng et al. (2005).

Experimental top

3-(1-Ethylpyrrole-2-carboxamido)propanoic acid (0.84 g, 4 mmol) was added to polyphosphoric acid (13 g) to which diphosphorus pentoxide (0.7 g, 5 mmol) had been added, and the mixture magnetically stirred at about 393 K for 0.5 h, and was then poured into ice-water and neutralized with NaOH solution. After filtration, the aqueous solution was extracted four times with ethyl acetate (15 ml). The organic phase was dried with sodium sulfate overnight. The solvent was removed by distillation under reduced pressure, and the pale-yellow solid residue was collected. The crude product was dissolved in the mixture of ethyl acetate (60%) and petroleum ether (40%), colorless monoclinic crystals suitable for X-ray analysis (m.p. 428 K, yield 65.3%) were obtained when the solution was exposed to air at room temperature for 5 d.

Refinement top

All non-H atoms were refined with anisotropic displacement parameters. The H atoms were positioned geometrically [C—H = 0.99Å for CH2, 0.98Å for CH3, 0.95Å for CH, and N—H = 0.88 Å] and refined using a riding model, with Uiso = 1.2Ueq (1.5Ueq for the methyl group) of the parent atom.

Computing details top

Data collection: SMART (Bruker,1999); cell refinement: SAINT-Plus (Bruker, 1999); data reduction: SAINT-Plus (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.
[Figure 2] Fig. 2. Crystal packing of (I) showing the chain formed by hydrogen bonds (dashed lines).
1-Ethyl-1H,6H-pyrrolo[2,3-c]azepine-4,8(5H,7H)-dione top
Crystal data top
C10H12N2O2Dx = 1.393 Mg m3
Mr = 192.22Melting point: 428 K
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
a = 11.703 (2) ÅCell parameters from 2801 reflections
b = 7.7863 (13) Åθ = 3.2–27.0°
c = 11.0004 (19) ŵ = 0.10 mm1
β = 113.878 (3)°T = 173 K
V = 916.6 (3) Å3Block, colourless
Z = 40.46 × 0.45 × 0.30 mm
F(000) = 408
Data collection top
Bruker SMART 1K CCD area-detector
diffractometer
1984 independent reflections
Radiation source: fine-focus sealed tube1661 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.021
ϕ and ω scansθmax = 27.0°, θmin = 1.9°
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
h = 1410
Tmin = 0.956, Tmax = 0.971k = 96
4523 measured reflectionsl = 1114
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.037Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.104H-atom parameters constrained
S = 1.07 w = 1/[σ2(Fo2) + (0.0534P)2 + 0.2795P]
where P = (Fo2 + 2Fc2)/3
1984 reflections(Δ/σ)max = 0.001
128 parametersΔρmax = 0.28 e Å3
0 restraintsΔρmin = 0.21 e Å3
Crystal data top
C10H12N2O2V = 916.6 (3) Å3
Mr = 192.22Z = 4
Monoclinic, P21/cMo Kα radiation
a = 11.703 (2) ŵ = 0.10 mm1
b = 7.7863 (13) ÅT = 173 K
c = 11.0004 (19) Å0.46 × 0.45 × 0.30 mm
β = 113.878 (3)°
Data collection top
Bruker SMART 1K CCD area-detector
diffractometer
1984 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 1996)
1661 reflections with I > 2σ(I)
Tmin = 0.956, Tmax = 0.971Rint = 0.021
4523 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0370 restraints
wR(F2) = 0.104H-atom parameters constrained
S = 1.07Δρmax = 0.28 e Å3
1984 reflectionsΔρmin = 0.21 e Å3
128 parameters
Special details top

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. 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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O20.07477 (9)0.05619 (12)0.30383 (10)0.0317 (3)
O10.47580 (8)0.04303 (12)0.16872 (9)0.0277 (2)
N20.35948 (10)0.26744 (13)0.18305 (11)0.0239 (3)
H2A0.42690.33220.21290.029*
N10.24341 (10)0.13996 (13)0.02340 (10)0.0222 (3)
C50.37313 (11)0.10354 (16)0.15418 (12)0.0210 (3)
C10.14174 (12)0.23379 (16)0.01642 (13)0.0255 (3)
H10.11000.33280.03720.031*
C40.25889 (11)0.00413 (15)0.10751 (12)0.0201 (3)
C70.19395 (13)0.28160 (17)0.26984 (14)0.0276 (3)
H7A0.26340.28600.35910.033*
H7B0.12830.36130.27050.033*
C30.16546 (11)0.01426 (15)0.15559 (12)0.0212 (3)
C80.14076 (11)0.10147 (16)0.24709 (12)0.0231 (3)
C20.09348 (12)0.16271 (16)0.09844 (13)0.0247 (3)
H20.02460.20460.11440.030*
C90.31226 (13)0.17678 (16)0.05965 (13)0.0257 (3)
H9A0.36820.07900.05420.031*
H9B0.25210.18820.15340.031*
C100.38929 (13)0.33927 (18)0.01768 (14)0.0312 (3)
H10A0.45170.32650.07370.047*
H10B0.43150.36000.07710.047*
H10C0.33450.43650.02250.047*
C60.24223 (12)0.34703 (16)0.16897 (13)0.0243 (3)
H6A0.17850.32450.07830.029*
H6B0.25430.47290.17930.029*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O20.0380 (6)0.0290 (5)0.0366 (5)0.0024 (4)0.0237 (5)0.0032 (4)
O10.0232 (5)0.0257 (5)0.0347 (5)0.0027 (4)0.0123 (4)0.0015 (4)
N20.0223 (5)0.0189 (5)0.0302 (6)0.0029 (4)0.0102 (4)0.0020 (4)
N10.0253 (5)0.0184 (5)0.0222 (5)0.0012 (4)0.0090 (4)0.0004 (4)
C50.0232 (6)0.0204 (6)0.0199 (6)0.0015 (5)0.0091 (5)0.0027 (5)
C10.0263 (7)0.0192 (6)0.0271 (6)0.0014 (5)0.0068 (5)0.0011 (5)
C40.0237 (6)0.0163 (5)0.0191 (6)0.0025 (5)0.0075 (5)0.0017 (4)
C70.0320 (7)0.0230 (6)0.0315 (7)0.0004 (5)0.0168 (6)0.0045 (5)
C30.0215 (6)0.0188 (6)0.0217 (6)0.0026 (5)0.0072 (5)0.0033 (5)
C80.0231 (6)0.0231 (6)0.0224 (6)0.0043 (5)0.0086 (5)0.0034 (5)
C20.0228 (6)0.0210 (6)0.0287 (6)0.0011 (5)0.0089 (5)0.0031 (5)
C90.0320 (7)0.0237 (6)0.0235 (6)0.0030 (5)0.0135 (5)0.0007 (5)
C100.0341 (8)0.0283 (7)0.0308 (7)0.0077 (6)0.0128 (6)0.0025 (6)
C60.0276 (7)0.0170 (6)0.0283 (6)0.0023 (5)0.0114 (5)0.0002 (5)
Geometric parameters (Å, º) top
O2—C81.2250 (15)C7—H7A0.9900
O1—C51.2393 (15)C7—H7B0.9900
N2—C51.3402 (16)C3—C21.4185 (17)
N2—C61.4556 (16)C3—C81.4643 (18)
N2—H2A0.8800C2—H20.9500
N1—C41.3681 (16)C9—C101.5131 (18)
N1—C11.3716 (16)C9—H9A0.9900
N1—C91.4704 (16)C9—H9B0.9900
C5—C41.4826 (17)C10—H10A0.9800
C1—C21.3609 (19)C10—H10B0.9800
C1—H10.9500C10—H10C0.9800
C4—C31.3964 (17)C6—H6A0.9900
C7—C81.5137 (18)C6—H6B0.9900
C7—C61.5223 (18)
C5—N2—C6125.30 (11)O2—C8—C3120.92 (12)
C5—N2—H2A117.4O2—C8—C7118.97 (11)
C6—N2—H2A117.4C3—C8—C7120.09 (11)
C4—N1—C1108.91 (10)C1—C2—C3107.09 (11)
C4—N1—C9127.96 (11)C1—C2—H2126.5
C1—N1—C9122.85 (11)C3—C2—H2126.5
O1—C5—N2122.26 (12)N1—C9—C10112.47 (11)
O1—C5—C4121.40 (11)N1—C9—H9A109.1
N2—C5—C4116.31 (11)C10—C9—H9A109.1
C2—C1—N1109.25 (11)N1—C9—H9B109.1
C2—C1—H1125.4C10—C9—H9B109.1
N1—C1—H1125.4H9A—C9—H9B107.8
N1—C4—C3107.63 (11)C9—C10—H10A109.5
N1—C4—C5121.69 (11)C9—C10—H10B109.5
C3—C4—C5129.45 (11)H10A—C10—H10B109.5
C8—C7—C6116.02 (11)C9—C10—H10C109.5
C8—C7—H7A108.3H10A—C10—H10C109.5
C6—C7—H7A108.3H10B—C10—H10C109.5
C8—C7—H7B108.3N2—C6—C7113.08 (11)
C6—C7—H7B108.3N2—C6—H6A109.0
H7A—C7—H7B107.4C7—C6—H6A109.0
C4—C3—C2107.08 (11)N2—C6—H6B109.0
C4—C3—C8128.93 (11)C7—C6—H6B109.0
C2—C3—C8123.99 (12)H6A—C6—H6B107.8
C6—N2—C5—O1179.77 (11)C5—C4—C3—C813.5 (2)
C6—N2—C5—C41.61 (17)C4—C3—C8—O2163.02 (12)
C4—N1—C1—C21.80 (14)C2—C3—C8—O217.16 (19)
C9—N1—C1—C2176.11 (11)C4—C3—C8—C718.71 (19)
C1—N1—C4—C30.68 (13)C2—C3—C8—C7161.10 (12)
C9—N1—C4—C3174.62 (11)C6—C7—C8—O2162.98 (12)
C1—N1—C4—C5169.12 (11)C6—C7—C8—C315.32 (17)
C9—N1—C4—C516.93 (18)N1—C1—C2—C32.15 (14)
O1—C5—C4—N130.73 (17)C4—C3—C2—C11.71 (14)
N2—C5—C4—N1151.09 (11)C8—C3—C2—C1178.14 (11)
O1—C5—C4—C3134.95 (14)C4—N1—C9—C10114.79 (14)
N2—C5—C4—C343.23 (18)C1—N1—C9—C1072.04 (15)
N1—C4—C3—C20.63 (13)C5—N2—C6—C769.94 (16)
C5—C4—C3—C2166.62 (12)C8—C7—C6—N272.98 (15)
N1—C4—C3—C8179.21 (11)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···O1i0.882.122.9043 (14)148
Symmetry code: (i) x+1, y+1/2, z+1/2.

Experimental details

Crystal data
Chemical formulaC10H12N2O2
Mr192.22
Crystal system, space groupMonoclinic, P21/c
Temperature (K)173
a, b, c (Å)11.703 (2), 7.7863 (13), 11.0004 (19)
β (°) 113.878 (3)
V3)916.6 (3)
Z4
Radiation typeMo Kα
µ (mm1)0.10
Crystal size (mm)0.46 × 0.45 × 0.30
Data collection
DiffractometerBruker SMART 1K CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Sheldrick, 1996)
Tmin, Tmax0.956, 0.971
No. of measured, independent and
observed [I > 2σ(I)] reflections
4523, 1984, 1661
Rint0.021
(sin θ/λ)max1)0.639
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.037, 0.104, 1.07
No. of reflections1984
No. of parameters128
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.28, 0.21

Computer programs: SMART (Bruker,1999), SAINT-Plus (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H2A···O1i0.882.122.9043 (14)148.4
Symmetry code: (i) x+1, y+1/2, z+1/2.
 

Acknowledgements

We thank the Natural Science Foundation of Guangdong Province, China (No. 06300581) for generously supporting this study.

References

First citationBanwell, M. G., Hamel, E., Hockless, D. C. R., Verdier-Pinard, P., Willis, A. C. & Wong, D. J. (2006). Bioorg. Med. Chem. 14, 4627–4638.  Web of Science CrossRef PubMed CAS Google Scholar
First citationBruker (1999). SMART and SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationLiu, J. F., Guo, S. P. & Jiang, B. (2005). Chin. J. Org. Chem. 25, 788–799.  CAS Google Scholar
First citationSheldrick, G. M. (1996). SADABS. University of Göttingen, Germany.  Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSosa, A. C. B., Yakushijin, K. & Horne, D. A. (2002). J. Org. Chem. 67, 4498–4500.  Web of Science CrossRef PubMed CAS Google Scholar
First citationZeng, X.-C. (2006). Acta Cryst. E62, o5505–o5507.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationZeng, X.-C., Xu, S.-H., Gu, J. & Deng, D.-S. (2005). Acta Cryst. E61, o795–o796.  Web of Science CSD CrossRef IUCr Journals Google Scholar

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