Ethyl 1-cyclo­propyl-6,7-difluoro-8-meth­oxy-4-oxo-1,4-dihydro­quinoline-3-carboxyl­ate

Wang, D.-C.; Huang, X.-M.; Liu, Y.-P.; Tang, C.-L.

doi:10.1107/S1600536808034715

organic compounds

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 64| Part 11| November 2008| Page o2214

doi:10.1107/S1600536808034715

Open

access

Ethyl 1-cyclopropyl-6,7-difluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate

De-Cai Wang,^a ^* Xin-Ming Huang,^a Yan-Ping Liu ^a and Chun-Lei Tang ^a

^aState Key Laboratory of Materials-Oriented Chemical Engineering, College of Life Sciences and Pharmaceutical Engineering, Nanjing University of Technology, Nanjing 210009, People's Republic of China
^*Correspondence e-mail: hxm36547870@163.com

(Received 16 October 2008; accepted 23 October 2008; online 31 October 2008)

In the title compound, C₁₆H₁₅F₂NO₄, the dihedral angle between the three-membered ring and the quinoline ring system is 64.3 (3)°. In the crystal structure, intermolecular C—H⋯O hydrogen bonds link the molecules, forming a column running along [101].

Related literature

The title compound is a key intermediate in the synthesis of a series of fluoroquinolones, see: Matsumoto et al. (1996 ); Nagano et al. (1989 ); Petersen et al. (1993 ).

Experimental

Crystal data

C₁₆H₁₅F₂NO₄
M_r = 323.29
Monoclinic, C 2/c
a = 16.395 (3) Å
b = 17.732 (4) Å
c = 12.199 (2) Å
β = 123.71 (3)°
V = 2950.1 (14) Å³
Z = 8
Mo Kα radiation
μ = 0.12 mm⁻¹
T = 293 (2) K
0.10 × 0.10 × 0.05 mm

Data collection

Enraf–Nonius CAD-4 diffractometer
Absorption correction: ψ scan (North et al., 1968 ) T_min = 0.988, T_max = 0.994
2760 measured reflections
2663 independent reflections
1580 reflections with I > 2σ(I)
R_int = 0.068
3 standard reflections every 200 reflections intensity decay: none

Refinement

R[F² > 2σ(F²)] = 0.061
wR(F²) = 0.175
S = 1.04
2663 reflections
208 parameters
H-atom parameters constrained
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C1—H1A⋯O2ⁱ	0.96	2.58	3.220 (8)	124
C12—H12B⋯O2ⁱⁱ	0.97	2.50	3.273 (5)	136
Symmetry codes: (i) $[-x, y, -z-{\script{1\over 2}}]$ ; (ii) $[-x+{\script{1\over 2}}, -y+{\script{1\over 2}}, -z]$ .

Data collection: CAD-4 Software (Enraf–Nonius, 1989 ); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995 ); 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: PLATON (Spek, 2003 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808034715/is2351sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536808034715/is2351Isup2.hkl

checkCIF report

Comment top

The title compound, 1-cyclopropyl-6,7-difluoro-1,4-dihydro-8-methoxy-4-oxo-3-quinolinecarboxylic acid ethyl ester, is a key intermediate to synthesize a series of fluoroquinolones,such as moxifloxacin (Petersen et al., 1993), balofloxacin (Nagano et al., 1989) and gatifloxacin (Matsumoto et al., 1996). As part of our studies in this area, we report here the synthesis and crystal structure of the title compound, (I) (Fig. 1).

The benzene ring and its adjacent six-membered ring were almost coplanar. The dihedral angles between the three-membered ring and the benzene ring is 65.30 (14)°. In the crystal structure, intermolecular C—H···O hydrogen bonds link the molecules, in which they are effective in the stabilization of the structure.

Related literature top

The title compound is a key intermediate in the synthesis of a series of fluoroquinolones, see: Matsumoto et al. (1996); Nagano et al. (1989); Petersen et al. (1993).

Experimental top

A solution of 26 g (0.075 mol) of 3-cyclopropylamino-2- (2,4,5-trifluoro-3-methoxybenzoyl)acrylic acid ethyl ester and 110 ml of DMF was treated with 22 g (0.16 mol) of K₂CO₃, and then heated to 50 °C with stirring for 1 h. The resulting precipitate was filtered, washed with the mixture of ice and water, and dried to give 23 g of the title compound (yield 95%). Crystals of (I) suitable for X-ray diffraction were obtained by slow evaporation of a methanol solution.

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1989); cell refinement: CAD-4 Software (Enraf–Nonius, 1989); data reduction: XCAD4 (Harms & Wocadlo, 1995); 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: PLATON (Spek, 2003).

Figures top

Fig. 1. The molecular structure of the title compound, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 30% probability level.

Ethyl 1-cyclopropyl-6,7-difluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate top

Crystal data top

C₁₆H₁₅F₂NO₄	F(000) = 1344
M_r = 323.29	D_x = 1.456 Mg m⁻³
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -C 2yc	Cell parameters from 25 reflections
a = 16.395 (3) Å	θ = 9–12°
b = 17.732 (4) Å	µ = 0.12 mm⁻¹
c = 12.199 (2) Å	T = 293 K
β = 123.71 (3)°	Block, colorless
V = 2950.1 (14) Å³	0.10 × 0.10 × 0.05 mm
Z = 8

Data collection top

Enraf–Nonius CAD-4 diffractometer	1580 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tube	R_int = 0.068
Graphite monochromator	θ_max = 25.2°, θ_min = 1.9°
ω/2θ scans	h = −2→19
Absorption correction: ψ scan (North et al., 1968)	k = 0→21
T_min = 0.988, T_max = 0.994	l = −14→12
2760 measured reflections	3 standard reflections every 200 reflections
2663 independent reflections	intensity decay: none

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)] = 0.061	H-atom parameters constrained
wR(F²) = 0.175	w = 1/[σ²(F_o²) + (0.06P)² + 5P] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max < 0.001
2663 reflections	Δρ_max = 0.21 e Å⁻³
208 parameters	Δρ_min = −0.19 e Å⁻³
0 restraints	Extinction correction: SHELXL97 (Sheldrick, 2008)
Primary atom site location: structure-invariant direct methods	Extinction coefficient: 0.0026 (5)

Crystal data top

C₁₆H₁₅F₂NO₄	V = 2950.1 (14) Å³
M_r = 323.29	Z = 8
Monoclinic, C2/c	Mo Kα radiation
a = 16.395 (3) Å	µ = 0.12 mm⁻¹
b = 17.732 (4) Å	T = 293 K
c = 12.199 (2) Å	0.10 × 0.10 × 0.05 mm
β = 123.71 (3)°

Data collection top

Enraf–Nonius CAD-4 diffractometer	1580 reflections with I > 2σ(I)
Absorption correction: ψ scan (North et al., 1968)	R_int = 0.068
T_min = 0.988, T_max = 0.994	3 standard reflections every 200 reflections
2760 measured reflections	intensity decay: none
2663 independent reflections

Refinement top

R[F² > 2σ(F²)] = 0.061	0 restraints
wR(F²) = 0.175	H-atom parameters constrained
S = 1.04	Δρ_max = 0.21 e Å⁻³
2663 reflections	Δρ_min = −0.19 e Å⁻³
208 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
N	0.1306 (2)	0.28705 (16)	−0.2762 (2)	0.0512 (7)
O1	0.1226 (2)	0.17328 (16)	−0.4536 (2)	0.0752 (8)
F1	0.1209 (2)	−0.01688 (12)	−0.1874 (3)	0.1108 (10)
C1	0.0365 (4)	0.1548 (3)	−0.5789 (4)	0.1079 (18)
H1A	−0.0094	0.1957	−0.6088	0.162*
H1B	0.0072	0.1100	−0.5709	0.162*
H1C	0.0539	0.1462	−0.6412	0.162*
O2	0.1328 (2)	0.21459 (14)	0.0430 (2)	0.0736 (8)
F2	0.1196 (2)	0.02669 (13)	−0.3966 (3)	0.0991 (9)
C2	0.1223 (2)	0.1543 (2)	−0.3446 (3)	0.0550 (9)
O3	0.1010 (3)	0.44539 (16)	−0.0591 (3)	0.0988 (11)
C3	0.1211 (3)	0.0799 (2)	−0.3166 (4)	0.0664 (10)
O4	0.11605 (19)	0.36229 (14)	0.0869 (2)	0.0666 (7)
C4	0.1229 (3)	0.0575 (2)	−0.2074 (4)	0.0689 (10)
C5	0.1266 (3)	0.1091 (2)	−0.1231 (4)	0.0604 (9)
H5A	0.1274	0.0935	−0.0497	0.073*
C6	0.1292 (2)	0.18552 (18)	−0.1466 (3)	0.0462 (8)
C7	0.1284 (2)	0.20942 (18)	−0.2564 (3)	0.0447 (8)
C8	0.1282 (2)	0.23918 (19)	−0.0548 (3)	0.0466 (8)
C9	0.1211 (2)	0.31671 (18)	−0.0906 (3)	0.0450 (8)
C10	0.1234 (2)	0.33541 (19)	−0.1976 (3)	0.0520 (8)
H10A	0.1196	0.3864	−0.2176	0.062*
C11	0.1438 (3)	0.3184 (2)	−0.3768 (3)	0.0650 (11)
H11A	0.0854	0.3183	−0.4672	0.078*
C12	0.2375 (3)	0.3084 (2)	−0.3630 (4)	0.0737 (11)
H12A	0.2362	0.3011	−0.4428	0.088*
H12B	0.2885	0.2807	−0.2869	0.088*
C13	0.2109 (3)	0.3841 (2)	−0.3402 (4)	0.0821 (13)
H13A	0.1928	0.4227	−0.4063	0.098*
H13B	0.2452	0.4024	−0.2502	0.098*
C14	0.1107 (3)	0.3813 (2)	−0.0227 (3)	0.0551 (9)
C15	0.1052 (3)	0.4226 (2)	0.1578 (4)	0.0711 (11)
H15A	0.0395	0.4435	0.1050	0.085*
H15B	0.1517	0.4626	0.1770	0.085*
C16	0.1232 (4)	0.3914 (3)	0.2797 (4)	0.0988 (16)
H16A	0.1172	0.4306	0.3291	0.148*
H16B	0.1882	0.3706	0.3308	0.148*
H16C	0.0762	0.3524	0.2595	0.148*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N	0.0654 (18)	0.0554 (18)	0.0445 (15)	0.0109 (13)	0.0378 (14)	0.0036 (13)
O1	0.097 (2)	0.087 (2)	0.0541 (15)	−0.0087 (15)	0.0494 (15)	−0.0196 (13)
F1	0.182 (3)	0.0485 (14)	0.160 (3)	−0.0203 (15)	0.131 (2)	−0.0184 (15)
C1	0.110 (4)	0.158 (5)	0.060 (3)	0.008 (3)	0.049 (3)	−0.025 (3)
O2	0.122 (2)	0.0632 (16)	0.0624 (16)	−0.0063 (15)	0.0677 (17)	−0.0018 (13)
F2	0.144 (2)	0.0714 (16)	0.119 (2)	−0.0169 (15)	0.0963 (19)	−0.0394 (14)
C2	0.051 (2)	0.070 (3)	0.0504 (19)	0.0013 (17)	0.0323 (16)	−0.0102 (17)
O3	0.189 (3)	0.0569 (18)	0.101 (2)	0.0292 (19)	0.112 (2)	0.0115 (16)
C3	0.076 (3)	0.061 (2)	0.075 (2)	−0.0102 (19)	0.050 (2)	−0.029 (2)
O4	0.105 (2)	0.0581 (15)	0.0640 (15)	0.0071 (13)	0.0637 (15)	−0.0046 (12)
C4	0.083 (3)	0.048 (2)	0.097 (3)	−0.0039 (19)	0.063 (2)	−0.003 (2)
C5	0.072 (2)	0.054 (2)	0.073 (2)	−0.0034 (18)	0.052 (2)	−0.0022 (19)
C6	0.0426 (17)	0.053 (2)	0.0471 (17)	−0.0039 (15)	0.0275 (15)	−0.0054 (15)
C7	0.0370 (16)	0.055 (2)	0.0448 (17)	0.0004 (14)	0.0242 (14)	−0.0072 (14)
C8	0.0433 (17)	0.059 (2)	0.0429 (17)	−0.0052 (15)	0.0273 (14)	−0.0085 (15)
C9	0.0409 (17)	0.058 (2)	0.0382 (15)	0.0037 (14)	0.0234 (13)	−0.0034 (15)
C10	0.063 (2)	0.052 (2)	0.0487 (18)	0.0101 (16)	0.0359 (17)	−0.0017 (16)
C11	0.100 (3)	0.066 (2)	0.0420 (18)	0.020 (2)	0.047 (2)	0.0113 (17)
C12	0.106 (3)	0.072 (3)	0.079 (3)	0.010 (2)	0.074 (3)	0.006 (2)
C13	0.143 (4)	0.060 (3)	0.084 (3)	0.005 (3)	0.089 (3)	0.009 (2)
C14	0.072 (2)	0.057 (2)	0.0516 (19)	0.0087 (18)	0.0432 (18)	0.0020 (17)
C15	0.107 (3)	0.064 (2)	0.071 (2)	0.012 (2)	0.068 (2)	−0.0086 (19)
C16	0.145 (4)	0.099 (4)	0.092 (3)	0.014 (3)	0.091 (3)	−0.011 (3)

Geometric parameters (Å, º) top

N—C10	1.340 (4)	C6—C7	1.398 (4)
N—C7	1.402 (4)	C6—C8	1.477 (4)
N—C11	1.468 (4)	C8—C9	1.428 (4)
O1—C2	1.373 (4)	C9—C10	1.367 (4)
O1—C1	1.429 (5)	C9—C14	1.479 (4)
F1—C4	1.345 (4)	C10—H10A	0.9300
C1—H1A	0.9600	C11—C12	1.462 (5)
C1—H1B	0.9600	C11—C13	1.491 (6)
C1—H1C	0.9600	C11—H11A	0.9800
O2—C8	1.233 (4)	C12—C13	1.485 (5)
F2—C3	1.348 (4)	C12—H12A	0.9700
C2—C3	1.365 (5)	C12—H12B	0.9700
C2—C7	1.416 (4)	C13—H13A	0.9700
O3—C14	1.198 (4)	C13—H13B	0.9700
C3—C4	1.374 (5)	C15—C16	1.455 (5)
O4—C14	1.333 (4)	C15—H15A	0.9700
O4—C15	1.448 (4)	C15—H15B	0.9700
C4—C5	1.353 (5)	C16—H16A	0.9600
C5—C6	1.391 (5)	C16—H16B	0.9600
C5—H5A	0.9300	C16—H16C	0.9600

C10—N—C7	119.0 (3)	N—C10—H10A	117.0
C10—N—C11	117.9 (3)	C9—C10—H10A	117.0
C7—N—C11	123.1 (3)	C12—C11—N	119.4 (3)
C2—O1—C1	116.6 (3)	C12—C11—C13	60.4 (3)
O1—C1—H1A	109.5	N—C11—C13	118.2 (3)
O1—C1—H1B	109.5	C12—C11—H11A	115.8
H1A—C1—H1B	109.5	N—C11—H11A	115.8
O1—C1—H1C	109.5	C13—C11—H11A	115.8
H1A—C1—H1C	109.5	C11—C12—C13	60.8 (3)
H1B—C1—H1C	109.5	C11—C12—H12A	117.7
C3—C2—O1	119.2 (3)	C13—C12—H12A	117.7
C3—C2—C7	118.8 (3)	C11—C12—H12B	117.7
O1—C2—C7	122.0 (3)	C13—C12—H12B	117.7
F2—C3—C2	119.5 (3)	H12A—C12—H12B	114.8
F2—C3—C4	118.7 (4)	C12—C13—C11	58.8 (3)
C2—C3—C4	121.8 (3)	C12—C13—H13A	117.9
C14—O4—C15	116.7 (3)	C11—C13—H13A	117.9
F1—C4—C5	121.3 (4)	C12—C13—H13B	117.9
F1—C4—C3	118.1 (4)	C11—C13—H13B	117.9
C5—C4—C3	120.6 (4)	H13A—C13—H13B	115.0
C4—C5—C6	119.7 (3)	O3—C14—O4	122.2 (3)
C4—C5—H5A	120.1	O3—C14—C9	124.0 (3)
C6—C5—H5A	120.1	O4—C14—C9	113.7 (3)
C5—C6—C7	120.5 (3)	O4—C15—C16	107.8 (3)
C5—C6—C8	117.2 (3)	O4—C15—H15A	110.1
C7—C6—C8	122.2 (3)	C16—C15—H15A	110.1
C6—C7—N	118.4 (3)	O4—C15—H15B	110.1
C6—C7—C2	118.6 (3)	C16—C15—H15B	110.1
N—C7—C2	123.0 (3)	H15A—C15—H15B	108.5
O2—C8—C9	126.0 (3)	C15—C16—H16A	109.5
O2—C8—C6	119.1 (3)	C15—C16—H16B	109.5
C9—C8—C6	115.0 (3)	H16A—C16—H16B	109.5
C10—C9—C8	119.0 (3)	C15—C16—H16C	109.5
C10—C9—C14	114.9 (3)	H16A—C16—H16C	109.5
C8—C9—C14	126.2 (3)	H16B—C16—H16C	109.5
N—C10—C9	126.0 (3)

C1—O1—C2—C3	66.2 (5)	C5—C6—C8—O2	5.6 (4)
C1—O1—C2—C7	−117.1 (4)	C7—C6—C8—O2	−177.2 (3)
O1—C2—C3—F2	−0.4 (5)	C5—C6—C8—C9	−174.0 (3)
C7—C2—C3—F2	−177.2 (3)	C7—C6—C8—C9	3.1 (4)
O1—C2—C3—C4	178.6 (3)	O2—C8—C9—C10	175.5 (3)
C7—C2—C3—C4	1.8 (6)	C6—C8—C9—C10	−4.9 (4)
F2—C3—C4—F1	−1.4 (6)	O2—C8—C9—C14	−4.8 (5)
C2—C3—C4—F1	179.6 (3)	C6—C8—C9—C14	174.8 (3)
F2—C3—C4—C5	178.6 (3)	C7—N—C10—C9	5.2 (5)
C2—C3—C4—C5	−0.5 (6)	C11—N—C10—C9	−172.8 (3)
F1—C4—C5—C6	179.6 (3)	C8—C9—C10—N	0.9 (5)
C3—C4—C5—C6	−0.4 (6)	C14—C9—C10—N	−178.8 (3)
C4—C5—C6—C7	−0.2 (5)	C10—N—C11—C12	110.6 (4)
C4—C5—C6—C8	177.0 (3)	C7—N—C11—C12	−67.3 (5)
C5—C6—C7—N	179.6 (3)	C10—N—C11—C13	40.6 (5)
C8—C6—C7—N	2.6 (4)	C7—N—C11—C13	−137.3 (3)
C5—C6—C7—C2	1.6 (4)	N—C11—C12—C13	−107.7 (4)
C8—C6—C7—C2	−175.5 (3)	N—C11—C13—C12	109.6 (4)
C10—N—C7—C6	−6.7 (4)	C15—O4—C14—O3	2.7 (5)
C11—N—C7—C6	171.2 (3)	C15—O4—C14—C9	−179.2 (3)
C10—N—C7—C2	171.3 (3)	C10—C9—C14—O3	2.8 (5)
C11—N—C7—C2	−10.8 (5)	C8—C9—C14—O3	−176.9 (4)
C3—C2—C7—C6	−2.3 (5)	C10—C9—C14—O4	−175.2 (3)
O1—C2—C7—C6	−179.0 (3)	C8—C9—C14—O4	5.1 (5)
C3—C2—C7—N	179.7 (3)	C14—O4—C15—C16	−174.3 (3)
O1—C2—C7—N	3.0 (5)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1A···O2ⁱ	0.96	2.58	3.220 (8)	124
C12—H12B···O2ⁱⁱ	0.97	2.50	3.273 (5)	136

Symmetry codes: (i) −x, y, −z−1/2; (ii) −x+1/2, −y+1/2, −z.

Experimental details

Crystal data
Chemical formula	C₁₆H₁₅F₂NO₄
M_r	323.29
Crystal system, space group	Monoclinic, C2/c
Temperature (K)	293
a, b, c (Å)	16.395 (3), 17.732 (4), 12.199 (2)
β (°)	123.71 (3)
V (Å³)	2950.1 (14)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.12
Crystal size (mm)	0.10 × 0.10 × 0.05

Data collection
Diffractometer	Enraf–Nonius CAD-4 diffractometer
Absorption correction	ψ scan (North et al., 1968)
T_min, T_max	0.988, 0.994
No. of measured, independent and observed [I > 2σ(I)] reflections	2760, 2663, 1580
R_int	0.068
(sin θ/λ)_max (Å⁻¹)	0.599

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.061, 0.175, 1.04
No. of reflections	2663
No. of parameters	208
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.21, −0.19

Computer programs: CAD-4 Software (Enraf–Nonius, 1989), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008), PLATON (Spek, 2003).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C1—H1A···O2ⁱ	0.96	2.58	3.220 (8)	124.0
C12—H12B···O2ⁱⁱ	0.97	2.50	3.273 (5)	136.0

Symmetry codes: (i) −x, y, −z−1/2; (ii) −x+1/2, −y+1/2, −z.

References

Enraf–Nonius (1989). CAD-4 Software. Enraf–Nonius, Delft, The Netherlands. Google Scholar
Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany. Google Scholar
Matsumoto, T., Hara, M. & Miyashita, K. (1996). PCT Int. Appl. WO 19 951 205. Google Scholar
Nagano, H., Yokota, T. & Katoh, Y. (1989). Eur. Pat. Appl. EP 89 108 963. 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. Pat. Appl. EP 92 122 058. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2003). J. Appl. Cryst. 36, 7–13. Web of Science CrossRef CAS IUCr Journals 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.

CRYSTALLOGRAPHIC
COMMUNICATIONS

ISSN: 2056-9890

Volume 64| Part 11| November 2008| Page o2214

doi:10.1107/S1600536808034715

Open

access

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Plain Text

Format		BIBTeX
		EndNote
		RefMan
		Refer
		Medline
		CIF
		SGML
		Plain Text

Search IUCr Journals		doi		Advanced search
Author		volume	page

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

Ethyl 1-cyclo­propyl-6,7-di­fluoro-8-meth­­oxy-4-oxo-1,4-di­hydro­quinoline-3-carboxyl­ate

Related literature

Experimental

Crystal data

Data collection

Refinement

Supporting information

References

organic compounds

Ethyl 1-cyclopropyl-6,7-difluoro-8-methoxy-4-oxo-1,4-dihydroquinoline-3-carboxylate