6-Benzyl-6,7-dihydro-5H-pyrrolo­[3,4-b]pyridine-5,7-dione

Sun, H.-S.; Jiang, L.; Xu, H.; Lu, X.-H.; Li, Y.-L.

doi:10.1107/S1600536811041006

organic compounds

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ISSN: 2056-9890

Volume 67| Part 11| November 2011| Page o2895

doi:10.1107/S1600536811041006

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6-Benzyl-6,7-dihydro-5H-pyrrolo[3,4-b]pyridine-5,7-dione

Hong-Shun Sun,^a ^* Long Jiang,^b Hong Xu,^c Xin-Hua Lu ^a and Yu-Long Li ^c

^aDepartment of Applied Chemistry, Nanjing College of Chemical Technology, Nanjing 210048, People's Republic of China, ^bR&D Center, Jiangsu Yabang Pharmaceutical Group, Changzhou 213200, People's Republic of China, and ^cDepartment of Chemical Engineering, Nanjing College of Chemical Technology, Nanjing 210048, People's Republic of China
^*Correspondence e-mail: njutshs@126.com

(Received 26 September 2011; accepted 5 October 2011; online 8 October 2011)

In the title compound, C₁₄H₁₀N₂O₂, the dihedral angle between the heterocyclic ring system and the phenyl ring is 45.8 (5)°. Weak intermolecular C—H⋯N hydrogen bonding is present in the crystal structure.

Related literature

The title compound is a key intermediate in the synthesis of the quinolone antibiotic moxifloxacin [systematic name: 1-cyclopropyl-7-[(1S,6S)-2,8-diazabicyclo[4.3.0]non-8-yl]-6-fluoro-8-methoxy-4-oxo-quinoline-3-carboxylic acid], see: Petersen et al. (1993 ). For a related structure, see: Garduño-Beltrán et al. (2009 ).

Experimental

Crystal data

C₁₄H₁₀N₂O₂
M_r = 238.24
Monoclinic, P 2₁ /c
a = 11.8548 (6) Å
b = 12.3969 (8) Å
c = 8.1676 (4) Å
β = 107.45 (3)°
V = 1145.1 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 293 K
0.20 × 0.10 × 0.10 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.981, T_max = 0.991
2087 measured reflections
2087 independent reflections
1100 reflections with I > 2σ(I)
R_int = 0.045
3 standard reflections every 200 reflections intensity decay: 1%

Refinement

R[F² > 2σ(F²)] = 0.058
wR(F²) = 0.174
S = 1.00
2087 reflections
163 parameters
12 restraints
H-atom parameters constrained
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.13 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C10—H10A⋯N2ⁱ	0.93	2.46	3.386 (3)	177
Symmetry code: (i) $[-x, y-{\script{1\over 2}}, -z+{\script{1\over 2}}]$ .

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); 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

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811041006/xu5342sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811041006/xu5342Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811041006/xu5342Isup3.cml

checkCIF report

Comment top

Moxifloxacin (Petersen et al., 1993) is used to treat a variety of bacterial infections. This medication belongs to a class of drugs called quinolone antibiotics. The title compound is a key intermediate to synthesize it. As part of our studies in this area, we report here its crystal structure.

In the title compound, all bond lengths and angles show normal values. The dihedral angle between the heterocycle and benzyl group is 45.8 (5)° (Fig.1), similar to that found in a related strcture (Garduño-Beltrán et al., 2009). There is a intermolecular C—H···N hydrogen bond (Table 1) in the crystal structure.

Related literature top

The title compound is a key intermediate in the synthesis of the quinolone antibiotic moxifloxacin [systematic name: 1-cyclopropyl-7-[(1S,6S)-2,8-diazabicyclo[4.3.0]non-8-yl]-6-fluoro-8-methoxy-4-oxo-quinoline-3-carboxylic acid], see: Petersen et al. (1993). For a related structure, see: Garduño-Beltrán et al. (2009).

Experimental top

Benzylamine (3.85 ml, 35.2 mmol) was added to a suspension of 2,3-pyridinedicarboxylic anhydride (5 g, 33.5 mmol) in acetic acid (50 ml), and the mixture was heated under reflux for 18 h. It was then cooled to room temperature, concentrated in vacuo and the residue was triturated with diethyl ether to afford the title compound as a white solid in 57% yield. Crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation of an acetone solution.

Computing details top

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994); cell refinement: CAD-4 EXPRESS (Enraf–Nonius, 1994); data reduction: XCAD4 (Harms & Wocadlo, 1995); 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).

Figures top

Fig. 1. The molecular structure of (I), showing the atom-numbering scheme and displacement ellipsoids at the 50% probability level.

6-Benzyl-6,7-dihydro-5H-pyrrolo[3,4-b]pyridine-5,7-dione top

Crystal data top

C₁₄H₁₀N₂O₂	F(000) = 496
M_r = 238.24	D_x = 1.382 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 25 reflections
a = 11.8548 (6) Å	θ = 10–13°
b = 12.3969 (8) Å	µ = 0.10 mm⁻¹
c = 8.1676 (4) Å	T = 293 K
β = 107.45 (3)°	Block, colorless
V = 1145.1 (2) Å³	0.20 × 0.10 × 0.10 mm
Z = 4

Data collection top

Enraf–Nonius CAD-4 diffractometer	1100 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.045
Graphite monochromator	θ_max = 25.4°, θ_min = 1.8°
ω/2θ scans	h = −14→13
Absorption correction: ψ scan (North et al., 1968)	k = 0→14
T_min = 0.981, T_max = 0.991	l = 0→9
2087 measured reflections	3 standard reflections every 200 reflections
2087 independent reflections	intensity decay: 1%

Refinement top

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)] = 0.058	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.174	H-atom parameters constrained
S = 1.00	w = 1/[σ²(F_o²) + (0.082P)²] where P = (F_o² + 2F_c²)/3
2087 reflections	(Δ/σ)_max < 0.001
163 parameters	Δρ_max = 0.17 e Å⁻³
12 restraints	Δρ_min = −0.13 e Å⁻³

Crystal data top

C₁₄H₁₀N₂O₂	V = 1145.1 (2) Å³
M_r = 238.24	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 11.8548 (6) Å	µ = 0.10 mm⁻¹
b = 12.3969 (8) Å	T = 293 K
c = 8.1676 (4) Å	0.20 × 0.10 × 0.10 mm
β = 107.45 (3)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	1100 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.045
T_min = 0.981, T_max = 0.991	3 standard reflections every 200 reflections
2087 measured reflections	intensity decay: 1%
2087 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.058	12 restraints
wR(F²) = 0.174	H-atom parameters constrained
S = 1.00	Δρ_max = 0.17 e Å⁻³
2087 reflections	Δρ_min = −0.13 e Å⁻³
163 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

	x	y	z	U_iso*/U_eq
N1	0.2267 (2)	0.6223 (2)	0.0923 (3)	0.0602 (7)
O1	0.20765 (18)	0.43903 (17)	0.1329 (3)	0.0753 (7)
C1	0.4977 (3)	0.7166 (3)	0.2368 (5)	0.0896 (11)
H1A	0.4640	0.7810	0.1871	0.108*
N2	−0.0141 (2)	0.74370 (19)	0.2194 (3)	0.0711 (7)
O2	0.19962 (18)	0.80705 (17)	0.0885 (3)	0.0782 (7)
C2	0.6005 (3)	0.7199 (3)	0.3733 (5)	0.0957 (12)
H2B	0.6327	0.7861	0.4170	0.115*
C3	0.6539 (3)	0.6287 (3)	0.4429 (4)	0.0763 (9)
H3A	0.7242	0.6307	0.5324	0.092*
C4	0.6038 (3)	0.5337 (3)	0.3807 (5)	0.0980 (13)
H4A	0.6398	0.4698	0.4289	0.118*
C5	0.5005 (3)	0.5297 (3)	0.2473 (5)	0.0919 (12)
H5A	0.4681	0.4630	0.2066	0.110*
C6	0.4446 (2)	0.6219 (2)	0.1734 (3)	0.0577 (8)
C7	0.3308 (3)	0.6186 (3)	0.0307 (4)	0.0758 (10)
H7A	0.3282	0.6793	−0.0454	0.091*
H7B	0.3282	0.5530	−0.0351	0.091*
C8	0.1751 (2)	0.5306 (2)	0.1379 (3)	0.0570 (8)
C9	0.0735 (2)	0.5705 (2)	0.1955 (3)	0.0505 (6)
C10	−0.0010 (2)	0.5161 (2)	0.2533 (3)	0.0493 (7)
H10A	0.0040	0.4415	0.2653	0.059*
C11	−0.0833 (3)	0.5716 (2)	0.2939 (4)	0.0655 (8)
H11A	−0.1372	0.5342	0.3353	0.079*
C12	−0.0940 (3)	0.6819 (2)	0.2785 (3)	0.0633 (8)
H12A	−0.1550	0.7164	0.3075	0.076*
C13	0.0710 (2)	0.6813 (2)	0.1768 (3)	0.0504 (6)
C14	0.1696 (3)	0.7163 (2)	0.1142 (3)	0.0581 (8)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0490 (14)	0.0711 (16)	0.0568 (14)	0.0019 (13)	0.0100 (11)	0.0026 (13)
O1	0.0755 (15)	0.0661 (14)	0.0803 (15)	0.0207 (12)	0.0173 (12)	−0.0042 (11)
C1	0.063 (2)	0.075 (2)	0.118 (3)	−0.0018 (18)	0.007 (2)	0.021 (2)
N2	0.0711 (18)	0.0628 (14)	0.0755 (17)	0.0089 (11)	0.0162 (13)	−0.0014 (12)
O2	0.0702 (15)	0.0627 (13)	0.0928 (16)	−0.0110 (11)	0.0108 (12)	0.0161 (11)
C2	0.067 (2)	0.084 (3)	0.120 (3)	−0.014 (2)	0.003 (2)	−0.005 (2)
C3	0.0509 (18)	0.101 (3)	0.076 (2)	−0.001 (2)	0.0185 (16)	0.001 (2)
C4	0.068 (2)	0.079 (3)	0.129 (3)	0.009 (2)	0.003 (2)	0.014 (2)
C5	0.073 (3)	0.072 (2)	0.113 (3)	−0.0044 (19)	0.000 (2)	−0.010 (2)
C6	0.0490 (16)	0.071 (2)	0.0572 (16)	0.0014 (16)	0.0227 (14)	0.0005 (16)
C7	0.0562 (19)	0.114 (3)	0.0586 (18)	−0.0033 (18)	0.0195 (16)	0.0010 (18)
C8	0.0532 (18)	0.0573 (19)	0.0503 (17)	0.0024 (15)	−0.0002 (13)	−0.0016 (13)
C9	0.0483 (15)	0.0511 (12)	0.0446 (15)	0.0002 (12)	0.0027 (12)	−0.0005 (12)
C10	0.0542 (17)	0.0359 (12)	0.0503 (15)	0.0001 (10)	0.0040 (12)	0.0023 (11)
C11	0.0599 (18)	0.0689 (14)	0.0665 (19)	0.0027 (14)	0.0171 (15)	0.0000 (16)
C12	0.0601 (19)	0.0673 (15)	0.0618 (18)	0.0126 (14)	0.0171 (14)	−0.0092 (16)
C13	0.0525 (15)	0.0481 (12)	0.0442 (14)	−0.0032 (12)	0.0049 (12)	0.0002 (12)
C14	0.0516 (18)	0.060 (2)	0.0516 (17)	−0.0023 (15)	−0.0014 (13)	0.0026 (14)

Geometric parameters (Å, º) top

N1—C14	1.385 (4)	C4—H4A	0.9300
N1—C8	1.394 (3)	C5—C6	1.367 (4)
N1—C7	1.467 (4)	C5—H5A	0.9300
O1—C8	1.203 (3)	C6—C7	1.496 (4)
C1—C6	1.359 (4)	C7—H7A	0.9700
C1—C2	1.384 (5)	C7—H7B	0.9700
C1—H1A	0.9300	C8—C9	1.503 (4)
N2—C13	1.395 (3)	C9—C10	1.306 (3)
N2—C12	1.411 (4)	C9—C13	1.382 (4)
O2—C14	1.217 (3)	C10—C11	1.315 (4)
C2—C3	1.336 (4)	C10—H10A	0.9300
C2—H2B	0.9300	C11—C12	1.376 (4)
C3—C4	1.347 (4)	C11—H11A	0.9300
C3—H3A	0.9300	C12—H12A	0.9300
C4—C5	1.374 (4)	C13—C14	1.474 (4)

C14—N1—C8	112.4 (2)	N1—C7—H7B	109.0
C14—N1—C7	124.4 (3)	C6—C7—H7B	109.0
C8—N1—C7	123.2 (3)	H7A—C7—H7B	107.8
C6—C1—C2	121.9 (3)	O1—C8—N1	126.2 (3)
C6—C1—H1A	119.1	O1—C8—C9	128.0 (3)
C2—C1—H1A	119.1	N1—C8—C9	105.8 (2)
C13—N2—C12	113.2 (2)	C10—C9—C13	124.0 (3)
C3—C2—C1	120.5 (3)	C10—C9—C8	129.5 (3)
C3—C2—H2B	119.7	C13—C9—C8	106.5 (3)
C1—C2—H2B	119.7	C9—C10—C11	117.1 (3)
C2—C3—C4	118.7 (3)	C9—C10—H10A	121.5
C2—C3—H3A	120.7	C11—C10—H10A	121.5
C4—C3—H3A	120.7	C10—C11—C12	123.4 (3)
C3—C4—C5	121.2 (3)	C10—C11—H11A	118.3
C3—C4—H4A	119.4	C12—C11—H11A	118.3
C5—C4—H4A	119.4	C11—C12—N2	121.3 (3)
C6—C5—C4	121.2 (3)	C11—C12—H12A	119.4
C6—C5—H5A	119.4	N2—C12—H12A	119.4
C4—C5—H5A	119.4	C9—C13—N2	121.1 (3)
C1—C6—C5	116.5 (3)	C9—C13—C14	109.8 (3)
C1—C6—C7	121.8 (3)	N2—C13—C14	129.1 (2)
C5—C6—C7	121.7 (3)	O2—C14—N1	125.2 (3)
N1—C7—C6	112.7 (2)	O2—C14—C13	129.4 (3)
N1—C7—H7A	109.0	N1—C14—C13	105.4 (2)
C6—C7—H7A	109.0

C6—C1—C2—C3	2.8 (6)	C13—C9—C10—C11	0.7 (4)
C1—C2—C3—C4	−1.9 (6)	C8—C9—C10—C11	−179.4 (2)
C2—C3—C4—C5	0.6 (6)	C9—C10—C11—C12	−0.1 (4)
C3—C4—C5—C6	−0.3 (6)	C10—C11—C12—N2	−1.1 (4)
C2—C1—C6—C5	−2.4 (5)	C13—N2—C12—C11	1.4 (4)
C2—C1—C6—C7	177.4 (3)	C10—C9—C13—N2	−0.2 (4)
C4—C5—C6—C1	1.1 (5)	C8—C9—C13—N2	179.9 (2)
C4—C5—C6—C7	−178.7 (3)	C10—C9—C13—C14	178.1 (2)
C14—N1—C7—C6	91.4 (3)	C8—C9—C13—C14	−1.8 (3)
C8—N1—C7—C6	−87.6 (3)	C12—N2—C13—C9	−0.8 (4)
C1—C6—C7—N1	−88.5 (4)	C12—N2—C13—C14	−178.8 (2)
C5—C6—C7—N1	91.3 (4)	C8—N1—C14—O2	177.7 (3)
C14—N1—C8—O1	−179.2 (3)	C7—N1—C14—O2	−1.4 (4)
C7—N1—C8—O1	−0.1 (4)	C8—N1—C14—C13	−1.1 (3)
C14—N1—C8—C9	0.0 (3)	C7—N1—C14—C13	179.8 (2)
C7—N1—C8—C9	179.2 (2)	C9—C13—C14—O2	−176.9 (3)
O1—C8—C9—C10	0.5 (5)	N2—C13—C14—O2	1.2 (5)
N1—C8—C9—C10	−178.7 (3)	C9—C13—C14—N1	1.8 (3)
O1—C8—C9—C13	−179.6 (3)	N2—C13—C14—N1	179.9 (2)
N1—C8—C9—C13	1.1 (3)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C10—H10A···N2ⁱ	0.93	2.46	3.386 (3)	177

Symmetry code: (i) −x, y−1/2, −z+1/2.

Experimental details

Crystal data
Chemical formula	C₁₄H₁₀N₂O₂
M_r	238.24
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	293
a, b, c (Å)	11.8548 (6), 12.3969 (8), 8.1676 (4)
β (°)	107.45 (3)
V (Å³)	1145.1 (2)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.20 × 0.10 × 0.10

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.981, 0.991
No. of measured, independent and observed [I > 2σ(I)] reflections	2087, 2087, 1100
R_int	0.045
(sin θ/λ)_max (Å⁻¹)	0.603

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.058, 0.174, 1.00
No. of reflections	2087
No. of parameters	163
No. of restraints	12
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.17, −0.13

Computer programs: CAD-4 EXPRESS (Enraf–Nonius, 1994), XCAD4 (Harms & Wocadlo, 1995), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C10—H10A···N2ⁱ	0.93	2.46	3.386 (3)	177

Symmetry code: (i) −x, y−1/2, −z+1/2.

Acknowledgements

The authors thank the Center of Testing and Analysis, Nanjing University, for support.

References

Enraf–Nonius (1994). CAD-4 EXPRESS. Enraf–Nonius, Delft, The Netherlands. Google Scholar
Garduño-Beltrán, O., Román-Bravo, P., Medrano, F. & Tlahuext, H. (2009). Acta Cryst. E65, o2581. Web of Science CSD CrossRef IUCr Journals Google Scholar
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359. CrossRef IUCr Journals Web of Science Google Scholar
Petersen, U., Krebs, A. & Schenke, T. (1993). Eur. Patent Appl. EP 92 122 058. Google Scholar
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