4,8-Dimeth­oxy­furo[2,3-b]quinoline (γ-fagarine)

Liu, Y.; Wei, K.; Yang, J.

doi:10.1107/S1600536811025062

organic compounds

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ISSN: 2056-9890

Volume 67| Part 8| August 2011| Page o1907

doi:10.1107/S1600536811025062

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4,8-Dimethoxyfuro[2,3-b]quinoline (γ-fagarine)

Yong Liu,^a Kou Wei ^a and Jianshe Yang ^b ^*

^aMedical College, Northwest University for Nationalities, Lanzhou 730030, Gansu Province, People's Republic of China, and ^bLife Sciences College, Northwest Normal University, Lanzhou 730030, Gansu Province, People's Republic of China
^*Correspondence e-mail: yangjianshe008@sohu.com

(Received 24 May 2011; accepted 25 June 2011; online 6 July 2011)

The title molecule, C₁₃H₁₁NO₃, a natural compound extracted from Phellodendron chinense, exhibits a near planar framework: the mean deviations from the furo[2,3-b]quinoline ring system and from the whole molecule (not including the H atoms) are 0.006 and 0.062 Å, respectively.

Related literature

For the anti-HIV properties of furoquinolines, see: Wang et al. (2009 ); Cheng et al. (2005 ). For a related furoquinoline structure, see: Napolitano et al. (2003 ).

Experimental

Crystal data

C₁₃H₁₁NO₃
M_r = 229.23
Orthorhombic, P b c a
a = 12.491 (5) Å
b = 12.155 (5) Å
c = 14.466 (5) Å
V = 2196.4 (14) Å³
Z = 8
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 296 K
0.25 × 0.22 × 0.21 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1998 ) T_min = 0.976, T_max = 0.979
11659 measured reflections
2047 independent reflections
1278 reflections with I > 2σ(I)
R_int = 0.068

Refinement

R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.129
S = 1.05
2047 reflections
157 parameters
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.12 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ); cell refinement: SAINT (Bruker, 2001 ); data reduction: SAINT; 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.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536811025062/bh2360sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536811025062/bh2360Isup2.hkl

Supporting information file. DOI: 10.1107/S1600536811025062/bh2360Isup3.cml

checkCIF report

Comment top

Furoquinoline is a planar unit, and its derivatives have been found to be potent anti-HIV compounds (Wang et al., 2009; Cheng et al., 2005). In the course of exploring new anti-HIV agents, we obtained a natural product, 4,8-dimethoxyfuro[2,3-b]quinoline, from phellodendron chinense. Here we report the structure and isolation of title compound.

The furo[2,3-b]quinoline ring system is near planar, exhibiting mean deviation of 0.006 Å. The two methoxy substitutional groups are nearly coplanar with the furo[2,3-b]quinoline ring system. The maximum distance from the four atoms of the two methoxy groups to the furo[2,3-b]quinoline framework mean plane is 0.300 (6) Å, for atom C14.

The title molecule crystallizes in space group Pbca, which is different from that of the closely related 4,7,8-trimethoxyfuro[2,3-b]quinoline (P2₁/c, Napolitano et al., 2003). There are no classic hydrogen bonds in the crystal structure of the title compound.

Related literature top

For the anti-HIV properties of furoquinolines, see: Wang et al. (2009); Cheng et al. (2005). For a related furoquinoline structure, see: Napolitano et al. (2003).

Experimental top

Phellodendron chinense (500 g) and 85% ethanol (1 L) were added to a 2 L flask. After refluxing the mixture for 5 h, the mixture was cooled to 300 K and filtrated. After the filtrate being condensed to 100 mL in water bath, the remains were extracted with ethyl acetate and dried over Na₂SO₄. After removing the solvent, the crude product was purified by a silica gel column using hexane/acetone, 3/1, as eluent, to give the title compound (1.10 g). Then the compound was dissolved in THF, and colorless crystals were formed on slow evaporation, at room temperature over one week.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2001); data reduction: SAINT (Bruker, 2001); 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

Fig. 1. The molecular structure of I with, displacement ellipsoids drawn at the 30% probability level. H atoms are presented as small spheres of arbitrary radius.

4,8-Dimethoxyfuro[2,3-b]quinoline top

Crystal data top

C₁₃H₁₁NO₃	F(000) = 960
M_r = 229.23	D_x = 1.386 Mg m⁻³
Orthorhombic, Pbca	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ac 2ab	Cell parameters from 1884 reflections
a = 12.491 (5) Å	θ = 2.7–24.2°
b = 12.155 (5) Å	µ = 0.10 mm⁻¹
c = 14.466 (5) Å	T = 296 K
V = 2196.4 (14) Å³	Block, colourless
Z = 8	0.25 × 0.22 × 0.21 mm

Data collection top

Bruker APEXII CCD diffractometer	2047 independent reflections
Radiation source: fine-focus sealed tube	1278 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.068
ϕ and ω scans	θ_max = 25.5°, θ_min = 2.7°
Absorption correction: multi-scan (SADABS; Sheldrick, 1998)	h = −15→13
T_min = 0.976, T_max = 0.979	k = −13→14
11659 measured reflections	l = −16→17

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.044	H-atom parameters constrained
wR(F²) = 0.129	w = 1/[σ²(F_o²) + (0.0376P)² + 0.5982P] where P = (F_o² + 2F_c²)/3
S = 1.05	(Δ/σ)_max = 0.001
2047 reflections	Δρ_max = 0.14 e Å⁻³
157 parameters	Δρ_min = −0.12 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008), Fc^*=kFc[1+0.001xFc²λ³/sin(2θ)]^-1/4
0 constraints	Extinction coefficient: 0.0037 (8)
Primary atom site location: structure-invariant direct methods

Crystal data top

C₁₃H₁₁NO₃	V = 2196.4 (14) Å³
M_r = 229.23	Z = 8
Orthorhombic, Pbca	Mo Kα radiation
a = 12.491 (5) Å	µ = 0.10 mm⁻¹
b = 12.155 (5) Å	T = 296 K
c = 14.466 (5) Å	0.25 × 0.22 × 0.21 mm

Data collection top

Bruker APEXII CCD diffractometer	2047 independent reflections
Absorption correction: multi-scan (SADABS; Sheldrick, 1998)	1278 reflections with I > 2σ(I)
T_min = 0.976, T_max = 0.979	R_int = 0.068
11659 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.044	0 restraints
wR(F²) = 0.129	H-atom parameters constrained
S = 1.05	Δρ_max = 0.14 e Å⁻³
2047 reflections	Δρ_min = −0.12 e Å⁻³
157 parameters

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	1.0282 (3)	0.2044 (2)	−0.15171 (19)	0.0791 (8)
H1	1.0559	0.2307	−0.2072	0.095*
C2	1.0798 (2)	0.21016 (18)	−0.07253 (17)	0.0654 (7)
H2	1.1474	0.2401	−0.0627	0.078*
C3	1.01087 (17)	0.16075 (15)	−0.00386 (14)	0.0474 (5)
C4	1.00926 (16)	0.13961 (15)	0.08969 (14)	0.0476 (5)
C5	0.91729 (17)	0.08795 (16)	0.12813 (14)	0.0484 (5)
C6	0.9100 (2)	0.06319 (18)	0.22317 (16)	0.0651 (7)
H6	0.9662	0.0807	0.2627	0.078*
C7	0.8204 (2)	0.0136 (2)	0.2568 (2)	0.0819 (9)
H7	0.8159	−0.0021	0.3196	0.098*
C8	0.7351 (2)	−0.0142 (2)	0.1989 (2)	0.0835 (9)
H8	0.6746	−0.0480	0.2233	0.100*
C9	0.7403 (2)	0.00804 (18)	0.1070 (2)	0.0684 (7)
C10	0.83121 (17)	0.06121 (16)	0.06827 (16)	0.0524 (6)
C12	0.91869 (19)	0.12867 (17)	−0.05247 (15)	0.0544 (6)
C13	1.18328 (18)	0.2155 (2)	0.12003 (19)	0.0788 (8)
H13A	1.2177	0.1688	0.0755	0.118*
H13B	1.2303	0.2269	0.1716	0.118*
H13C	1.1667	0.2850	0.0920	0.118*
C14	0.5786 (3)	−0.0878 (3)	0.0754 (3)	0.1463 (17)
H14A	0.6090	−0.1531	0.1020	0.219*
H14B	0.5337	−0.1076	0.0242	0.219*
H14C	0.5367	−0.0501	0.1211	0.219*
N1	0.83129 (15)	0.08188 (15)	−0.02441 (14)	0.0603 (5)
O1	0.92925 (15)	0.15576 (15)	−0.14407 (11)	0.0756 (5)
O2	1.08678 (12)	0.16444 (13)	0.15127 (10)	0.0655 (5)
O3	0.66204 (14)	−0.01773 (15)	0.04411 (16)	0.0967 (7)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.102 (2)	0.0731 (17)	0.0625 (18)	0.0109 (16)	0.0183 (17)	0.0169 (14)
C2	0.0779 (17)	0.0560 (14)	0.0623 (16)	0.0018 (12)	0.0185 (14)	0.0051 (12)
C3	0.0573 (13)	0.0387 (10)	0.0461 (12)	0.0039 (9)	0.0084 (10)	−0.0004 (9)
C4	0.0533 (13)	0.0420 (11)	0.0475 (13)	0.0008 (9)	0.0042 (11)	−0.0061 (9)
C5	0.0569 (13)	0.0397 (11)	0.0487 (13)	0.0001 (10)	0.0111 (11)	−0.0039 (9)
C6	0.0844 (18)	0.0595 (14)	0.0515 (15)	−0.0051 (13)	0.0160 (13)	−0.0006 (11)
C7	0.109 (2)	0.0672 (17)	0.0693 (18)	−0.0039 (16)	0.0394 (18)	0.0059 (14)
C8	0.076 (2)	0.0610 (16)	0.114 (3)	−0.0144 (14)	0.0458 (18)	−0.0081 (16)
C9	0.0574 (15)	0.0513 (13)	0.097 (2)	−0.0045 (12)	0.0184 (15)	−0.0099 (14)
C10	0.0535 (14)	0.0390 (11)	0.0647 (16)	0.0026 (10)	0.0100 (12)	−0.0055 (10)
C12	0.0681 (16)	0.0475 (12)	0.0476 (14)	0.0119 (11)	−0.0006 (12)	−0.0002 (10)
C13	0.0597 (15)	0.0896 (19)	0.0872 (19)	−0.0186 (14)	0.0017 (14)	−0.0050 (15)
C14	0.097 (2)	0.120 (3)	0.221 (5)	−0.061 (2)	0.023 (3)	−0.039 (3)
N1	0.0608 (13)	0.0559 (12)	0.0641 (14)	0.0049 (9)	−0.0062 (10)	−0.0050 (10)
O1	0.0975 (14)	0.0816 (12)	0.0476 (10)	0.0149 (10)	−0.0040 (10)	0.0084 (8)
O2	0.0644 (10)	0.0786 (11)	0.0535 (10)	−0.0168 (8)	0.0009 (8)	−0.0068 (8)
O3	0.0616 (11)	0.0872 (13)	0.1413 (19)	−0.0202 (10)	0.0027 (12)	−0.0185 (12)

Geometric parameters (Å, º) top

C1—C2	1.316 (3)	C8—C9	1.358 (4)
C1—O1	1.375 (3)	C8—H8	0.9300
C1—H1	0.9300	C9—O3	1.372 (3)
C2—C3	1.446 (3)	C9—C10	1.422 (3)
C2—H2	0.9300	C10—N1	1.364 (3)
C3—C4	1.378 (3)	C12—N1	1.296 (3)
C3—C12	1.404 (3)	C12—O1	1.372 (3)
C4—O2	1.350 (2)	C13—O2	1.429 (3)
C4—C5	1.422 (3)	C13—H13A	0.9600
C5—C6	1.410 (3)	C13—H13B	0.9600
C5—C10	1.418 (3)	C13—H13C	0.9600
C6—C7	1.361 (3)	C14—O3	1.420 (3)
C6—H6	0.9300	C14—H14A	0.9600
C7—C8	1.397 (4)	C14—H14B	0.9600
C7—H7	0.9300	C14—H14C	0.9600

C2—C1—O1	113.2 (2)	C8—C9—C10	120.9 (3)
C2—C1—H1	123.4	O3—C9—C10	114.3 (2)
O1—C1—H1	123.4	N1—C10—C5	123.87 (19)
C1—C2—C3	106.5 (2)	N1—C10—C9	118.1 (2)
C1—C2—H2	126.7	C5—C10—C9	118.0 (2)
C3—C2—H2	126.7	N1—C12—O1	119.3 (2)
C4—C3—C12	115.35 (19)	N1—C12—C3	131.0 (2)
C4—C3—C2	139.6 (2)	O1—C12—C3	109.8 (2)
C12—C3—C2	105.1 (2)	O2—C13—H13A	109.5
O2—C4—C3	126.58 (19)	O2—C13—H13B	109.5
O2—C4—C5	114.85 (19)	H13A—C13—H13B	109.5
C3—C4—C5	118.56 (19)	O2—C13—H13C	109.5
C6—C5—C10	119.8 (2)	H13A—C13—H13C	109.5
C6—C5—C4	121.8 (2)	H13B—C13—H13C	109.5
C10—C5—C4	118.35 (19)	O3—C14—H14A	109.5
C7—C6—C5	119.7 (2)	O3—C14—H14B	109.5
C7—C6—H6	120.1	H14A—C14—H14B	109.5
C5—C6—H6	120.1	O3—C14—H14C	109.5
C6—C7—C8	121.3 (3)	H14A—C14—H14C	109.5
C6—C7—H7	119.3	H14B—C14—H14C	109.5
C8—C7—H7	119.3	C12—N1—C10	112.91 (19)
C9—C8—C7	120.2 (2)	C12—O1—C1	105.51 (19)
C9—C8—H8	119.9	C4—O2—C13	119.57 (18)
C7—C8—H8	119.9	C9—O3—C14	116.6 (3)
C8—C9—O3	124.8 (2)

O1—C1—C2—C3	0.2 (3)	C4—C5—C10—C9	179.04 (18)
C1—C2—C3—C4	−178.6 (2)	C8—C9—C10—N1	−179.6 (2)
C1—C2—C3—C12	−0.2 (2)	O3—C9—C10—N1	0.7 (3)
C12—C3—C4—O2	−178.62 (18)	C8—C9—C10—C5	1.4 (3)
C2—C3—C4—O2	−0.3 (4)	O3—C9—C10—C5	−178.24 (18)
C12—C3—C4—C5	0.4 (3)	C4—C3—C12—N1	−0.1 (3)
C2—C3—C4—C5	178.7 (2)	C2—C3—C12—N1	−179.0 (2)
O2—C4—C5—C6	−1.2 (3)	C4—C3—C12—O1	178.92 (17)
C3—C4—C5—C6	179.67 (19)	C2—C3—C12—O1	0.1 (2)
O2—C4—C5—C10	178.73 (17)	O1—C12—N1—C10	−179.06 (18)
C3—C4—C5—C10	−0.4 (3)	C3—C12—N1—C10	−0.1 (3)
C10—C5—C6—C7	0.1 (3)	C5—C10—N1—C12	0.1 (3)
C4—C5—C6—C7	−179.9 (2)	C9—C10—N1—C12	−178.82 (18)
C5—C6—C7—C8	0.4 (4)	N1—C12—O1—C1	179.27 (19)
C6—C7—C8—C9	0.0 (4)	C3—C12—O1—C1	0.1 (2)
C7—C8—C9—O3	178.7 (2)	C2—C1—O1—C12	−0.2 (3)
C7—C8—C9—C10	−1.0 (4)	C3—C4—O2—C13	−1.7 (3)
C6—C5—C10—N1	−179.89 (19)	C5—C4—O2—C13	179.32 (19)
C4—C5—C10—N1	0.2 (3)	C8—C9—O3—C14	−10.6 (4)
C6—C5—C10—C9	−1.0 (3)	C10—C9—O3—C14	169.1 (2)

Experimental details

Crystal data
Chemical formula	C₁₃H₁₁NO₃
M_r	229.23
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	296
a, b, c (Å)	12.491 (5), 12.155 (5), 14.466 (5)
V (Å³)	2196.4 (14)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.10
Crystal size (mm)	0.25 × 0.22 × 0.21

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Sheldrick, 1998)
T_min, T_max	0.976, 0.979
No. of measured, independent and observed [I > 2σ(I)] reflections	11659, 2047, 1278
R_int	0.068
(sin θ/λ)_max (Å⁻¹)	0.606

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.129, 1.05
No. of reflections	2047
No. of parameters	157
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.14, −0.12

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Acknowledgements

Financial support from the Fundamental Research Funds for the Central Universities in NWSUAF (QN2009048) and the Excellent Young Funds 211020712 is greatly appreciated.

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