organic papers
Acta Cryst.(2004). E60, o1641±o1642 DOI: 10.1107/S1600536804020884 Shen Yudonget al. C8H6ClN3
o1641
Acta Crystallographica Section EStructure Reports Online
ISSN 1600-5368
2-Amino-7-chloro-1,8-naphthyridine
Yudong Shen,aHaiqiang Wu,a Xianzhang Bub* and Lianquan Gua
aSchool of Chemistry and Chemical Engineering,
Sun Yat-sen University, Guangzhou 510275, People's Republic of China, andbSchool of
Pharmaceutical Sciences, Sun Yat-sen University, Guangzhou 510080, People's Republic of China
Correspondence e-mail: cep02syd@student.zsu.edu.cn
Key indicators
Single-crystal X-ray study
T= 293 K
Mean(C±C) = 0.003 AÊ
Rfactor = 0.036
wRfactor = 0.108
Data-to-parameter ratio = 16.0
For details of how these key indicators were automatically derived from the article, see http://journals.iucr.org/e.
#2004 International Union of Crystallography Printed in Great Britain ± all rights reserved
The title compound, C8H6ClN3, has been structurally
char-acterized. Intermolecular NÐH N hydrogen bonds give rise to a dimer structure, which is further extended into a one-dimensional chain parallel to the a axis through ±
interactions.
Comment
In recent years, research on derivatives of 1,8-naphthyridine has been intensive because these compounds show a wide range of biological activities, such as anti-in¯ammatory activity (Roma et al., 2000), highly selective alkylation and cleavage reagent of DNA (Nakatani, Sando, Kumasawaet al., 2001; Nakatani, Sando, Yoshida & Saito, 2001; Nakataniet al., 2000), molecular beacon (Smith et al., 2002), and antiviral activity (Bachandet al., 2002). As part of our investigation of derivatives of 1,8-naphthyridine, we report here the synthesis and crystal structure of 2-amino-7-chloro-1,8-naphthyridine, (I).
The CÐN and CÐC distances in (I) show no remarkable features, with CÐN distances in the range 1.307 (2)± 1.363 (2) AÊ; these are shorter than the single-bond distance of 1.480 AÊ and longer than the typical C N distances of 1.280 AÊ, indicating partial double-bond character. This can be interpreted in terms of conjugation in the heterocycle. The title molecule acts as both hydrogen-bond donor and acceptor
Received 11 August 2004 Accepted 24 August 2004 Online 31 August 2004
Figure 1
to form a dimer with another molecule through NÐH N hydrogen bonds. There are±interactions [the centroid-to-centroid distance is 3.636 (4) AÊ and the perpendicular distances are 3.354 and 3.356 AÊ] between dimers that lead to a one-dimensional chain parallel to theaaxis.
Experimental
The title compound, (I), was prepared using a method similar to that reported by Newkomeet al.(1981). Malic acid (3 g, 22 mmol) and 2,6-diaminopyridine (2.2 g, 20 mmol) were ground to an intimate powder and cooled in an ice bath, and then concentrated sulfuric acid (10 ml) was added dropwise. The solution was heated at 383 K for 2±3 h, poured over ice and then made alkaline with concentrated ammo-nium hydroxide (pH 8). 2-Amino-7-hydroxy-1,8-naphthyridine was isolated in 92% yield. A mixture of 2-amino-7-hydroxy-1,8-naph-thyridine (3.2 g, 20 mmol), phosphorus pentachloride (4.7 g, 22.5 mmol) and phosphorus oxychloride (5 ml, 54 mmol) was re¯uxed for 2 h, ice was carefully added and the solution was made alkaline with sodium carbonate. The precipitate was collected and recrystallized from acetone to give (I) in 70% yield. Crystals of (I) suitable for X-ray analysis were grown from an acetone solution (m.p. 452±455 K).1H NMR (500 Hz, CDCl
3, TMS):7.86 (d, J= 8 Hz, 1H),
7.84 (d, J= 9 Hz, 1H), 7.18 (d, J= 8 Hz, 1H), 6.79 (d, J= 9 Hz, 1H), 5.50 (s,br, 2H).
Crystal data C8H6ClN3 Mr= 179.61
Monoclinic,P21=n a= 6.906 (7) AÊ b= 12.538 (13) AÊ c= 9.099 (9) AÊ
= 91.012 (17)
V= 787.7 (14) AÊ3 Z= 4
Dx= 1.515 Mg mÿ3
MoKradiation Cell parameters from 3155
re¯ections
= 2.8±27.2
= 0.42 mmÿ1 T= 293 (2) K Block, orange 0.500.400.35 mm Data collection
Bruker SMART CCD area-detector diffractometer
'and!scans
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) Tmin= 0.816,Tmax= 0.866 4791 measured re¯ections
1749 independent re¯ections 1498 re¯ections withI> 2(I) Rint= 0.020
max= 27.2 h=ÿ8!8 k=ÿ15!9 l=ÿ11!11 Re®nement
Re®nement onF2 R[F2> 2(F2)] = 0.036 wR(F2) = 0.108 S= 1.05 1749 re¯ections 109 parameters
H atom parameters constrained
w= 1/[2(F
o2) + (0.0589P)2
+ 0.2069P]
whereP= (Fo2+ 2Fc2)/3
(/)max< 0.001
max= 0.29 e AÊÿ3
min=ÿ0.25 e AÊÿ3
Table 1
Selected bond distances (AÊ).
N1ÐC1 1.307 (2) N1ÐC5 1.363 (2) N2ÐC8 1.329 (2) N2ÐC5 1.354 (2) C2ÐC3 1.363 (3) C2ÐC1 1.399 (2)
C5ÐC4 1.418 (2) C4ÐC3 1.398 (2) C4ÐC6 1.418 (2) C8ÐC7 1.435 (2) C6ÐC7 1.344 (3)
Table 2
Hydrogen-bonding geometry (AÊ,).
DÐH A DÐH H A D A DÐH A
N3ÐH3A N2i 0.86 2.12 2.974 (3) 172
Symmetry code: (i) 1ÿx;1ÿy;1ÿz.
H atoms were placed in calculated positions, with CÐH = 0.93 AÊ and NÐH = 0.86 AÊ, and re®ned using a riding model, withUiso(H) =
1.2Ueq(C,N).
Data collection:SMART(Bruker, 1998); cell re®nement:SAINT
(Bruker, 1999); data reduction:SAINT; program(s) used to solve structure:SHELXS97 (Sheldrick, 1997); program(s) used to re®ne structure: SHELXL97 (Sheldrick, 1997); molecular graphics:
SHELXTL (Bruker, 1998); software used to prepare material for publication:SHELXTL.
This work was supported by the National Natural Science Foundation of China and the Natural Science Foundation of Guangdong Province. The authors thank Seik Weng Ng for help.
References
Bachand, B., Nguyen-Ba, N., Siddiqui, A. & Levesque, S. (2002). US Patent No. 20020099072A1.
Bruker (1998).SMART(Version 5.0) andSHELXTL(Version 5.1). Bruker AXS Inc., Madison, Wisconsin, USA.
Bruker (1999).SAINT.Bruker AXS Inc., Madison, Wisconsin, USA. Nakatani, K., Sando, S., Kumasawa, H., Kikuchi, J. & Saito, I. (2001).J. Am.
Chem. Soc.123, 12650±12657.
Nakatani, K., Sando, S. & Saito, I. (2000).J. Am. Chem. Soc.122, 2172± 2177.
Nakatani, K., Sando, S., Yoshida, K. & Saito, I. (2001).Bioorg. Med. Chem. Lett.11, 335±337.
Newkome, G. R., Garbis, S. J., Majestic, V. K., Fronczek, F. R. & Chiari, G. (1981).J. Org. Chem.46, 833±839.
Roma, G., Di Braccio, M., Grossi, G., Mattioli, F. & Ghia, M. (2000).Eur. J. Med. Chem.35, 1021±1035.
Sheldrick, G. M. (1996).SADABS.University of GoÈttingen, Germany. Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of
GoÈttingen, Germany.
Smith, E. A., Kyo, M., Kumasawa, H., Nakatani, K., Saito, I. & Corn, R. M. (2002).J. Am. Chem. Soc.124, 6810±6811.
Figure 2
supporting information
sup-1 Acta Cryst. (2004). E60, o1641–o1642
supporting information
Acta Cryst. (2004). E60, o1641–o1642 [https://doi.org/10.1107/S1600536804020884]
2-Amino-7-chloro-1,8-naphthyridine
Yudong Shen, Haiqiang Wu, Xianzhang Bu and Lianquan Gu
2-amino-7-chloro-1,8-naphthyridine
Crystal data
C8H6ClN3
Mr = 179.61
Monoclinic, P21/n Hall symbol: -P 2yn
a = 6.906 (7) Å
b = 12.538 (13) Å
c = 9.099 (9) Å
β = 91.012 (17)°
V = 787.7 (14) Å3
Z = 4
F(000) = 368
Dx = 1.515 Mg m−3
Melting point = 452–455 K Mo Kα radiation, λ = 0.71073 Å Cell parameters from 3155 reflections
θ = 2.8–27.2°
µ = 0.42 mm−1
T = 293 K Block, orange
0.50 × 0.40 × 0.35 mm
Data collection
Bruker SMART CCD area-detector diffractometer
Radiation source: fine-focus sealed tube Graphite monochromator
φ and ω scans
Absorption correction: multi-scan (SADABS; Sheldrick, 1996)
Tmin = 0.816, Tmax = 0.866
4791 measured reflections 1749 independent reflections 1498 reflections with I > 2σ(I)
Rint = 0.020
θmax = 27.2°, θmin = 2.8°
h = −8→8
k = −15→9
l = −11→11
Refinement
Refinement on F2 Least-squares matrix: full
R[F2 > 2σ(F2)] = 0.036
wR(F2) = 0.108
S = 1.05 1749 reflections 109 parameters 0 restraints
Primary atom site location: structure-invariant direct methods
Secondary atom site location: difference Fourier map
Hydrogen site location: inferred from neighbouring sites
H atoms treated by a mixture of independent and constrained refinement
w = 1/[σ2(F
o2) + (0.0589P)2 + 0.2069P] where P = (Fo2 + 2Fc2)/3
(Δ/σ)max < 0.001 Δρmax = 0.29 e Å−3 Δρmin = −0.25 e Å−3
Special details
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)
x y z Uiso*/Ueq
Cl1 1.14367 (7) 0.81937 (4) 0.55480 (5) 0.06047 (19)
N1 0.92935 (19) 0.66304 (10) 0.45997 (13) 0.0409 (3)
N2 0.71727 (17) 0.52888 (10) 0.39707 (13) 0.0406 (3)
C2 1.2349 (2) 0.68261 (13) 0.33712 (19) 0.0507 (4)
H2 1.3502 0.7204 0.3293 0.061*
N3 0.5031 (2) 0.39486 (12) 0.34545 (16) 0.0556 (4)
H3A 0.4302 0.4187 0.4137 0.067*
H3B 0.4684 0.3396 0.2956 0.067*
C5 0.8888 (2) 0.57736 (11) 0.37248 (14) 0.0368 (3)
C1 1.0958 (2) 0.71003 (13) 0.44037 (16) 0.0434 (3)
C4 1.0192 (2) 0.54205 (12) 0.26415 (15) 0.0399 (3)
C8 0.6709 (2) 0.44386 (13) 0.31670 (16) 0.0425 (3)
C3 1.1932 (2) 0.59769 (14) 0.24847 (18) 0.0484 (4)
H3 1.2805 0.5767 0.1774 0.058*
C6 0.9629 (2) 0.45210 (13) 0.17916 (16) 0.0465 (4)
H6 1.0436 0.4267 0.1063 0.056*
C7 0.7931 (3) 0.40338 (14) 0.20357 (17) 0.0477 (4)
H7 0.7554 0.3444 0.1481 0.057*
Atomic displacement parameters (Å2)
U11 U22 U33 U12 U13 U23
Cl1 0.0608 (3) 0.0563 (3) 0.0647 (3) −0.01606 (19) 0.0119 (2) −0.01139 (19)
N1 0.0409 (6) 0.0425 (7) 0.0395 (6) 0.0004 (5) 0.0062 (5) 0.0014 (5)
N2 0.0381 (6) 0.0451 (7) 0.0387 (6) 0.0002 (5) 0.0059 (5) −0.0019 (5)
C2 0.0427 (8) 0.0528 (9) 0.0571 (9) −0.0042 (7) 0.0129 (7) 0.0069 (7)
N3 0.0478 (7) 0.0600 (9) 0.0593 (8) −0.0114 (7) 0.0097 (6) −0.0190 (7)
C5 0.0371 (7) 0.0403 (7) 0.0331 (6) 0.0045 (5) 0.0043 (5) 0.0057 (5)
C1 0.0453 (8) 0.0423 (8) 0.0428 (7) −0.0013 (6) 0.0054 (6) 0.0040 (6)
C4 0.0416 (7) 0.0427 (8) 0.0358 (7) 0.0075 (6) 0.0076 (5) 0.0068 (6)
C8 0.0419 (8) 0.0468 (8) 0.0388 (7) 0.0017 (6) 0.0020 (6) −0.0003 (6)
C3 0.0464 (8) 0.0525 (9) 0.0469 (8) 0.0044 (7) 0.0178 (7) 0.0060 (7)
C6 0.0540 (9) 0.0485 (9) 0.0375 (7) 0.0104 (7) 0.0121 (6) 0.0007 (6)
C7 0.0564 (9) 0.0463 (9) 0.0405 (8) 0.0022 (7) 0.0047 (6) −0.0066 (6)
Geometric parameters (Å, º)
Cl1—C1 1.749 (2) N3—H3B 0.8600
N1—C1 1.307 (2) C5—C4 1.418 (2)
supporting information
sup-3 Acta Cryst. (2004). E60, o1641–o1642
N2—C8 1.329 (2) C4—C6 1.418 (2)
N2—C5 1.354 (2) C8—C7 1.435 (2)
C2—C3 1.363 (3) C3—H3 0.9300
C2—C1 1.399 (2) C6—C7 1.344 (3)
C2—H2 0.9300 C6—H6 0.9300
N3—C8 1.342 (2) C7—H7 0.9300
N3—H3A 0.8600
C1—N1—C5 116.60 (13) C3—C4—C6 124.69 (14)
C8—N2—C5 118.18 (12) C5—C4—C6 117.11 (14)
C3—C2—C1 116.66 (15) N2—C8—N3 117.42 (14)
C3—C2—H2 121.7 N2—C8—C7 122.66 (15)
C1—C2—H2 121.7 N3—C8—C7 119.92 (15)
C8—N3—H3A 120.0 C2—C3—C4 120.14 (14)
C8—N3—H3B 120.0 C2—C3—H3 119.9
H3A—N3—H3B 120.0 C4—C3—H3 119.9
N2—C5—N1 115.39 (12) C7—C6—C4 120.22 (14)
N2—C5—C4 122.91 (14) C7—C6—H6 119.9
N1—C5—C4 121.70 (14) C4—C6—H6 119.9
N1—C1—C2 126.68 (16) C6—C7—C8 118.91 (16)
N1—C1—Cl1 115.45 (12) C6—C7—H7 120.5
C2—C1—Cl1 117.87 (13) C8—C7—H7 120.5
C3—C4—C5 118.20 (15)
C8—N2—C5—N1 −178.99 (13) N1—C5—C4—C6 179.98 (13)
C8—N2—C5—C4 0.7 (2) C5—N2—C8—N3 178.06 (14)
C1—N1—C5—N2 178.74 (13) C5—N2—C8—C7 −1.4 (2)
C1—N1—C5—C4 −1.0 (2) C1—C2—C3—C4 −0.6 (2)
C5—N1—C1—C2 1.2 (2) C5—C4—C3—C2 0.8 (2)
C5—N1—C1—Cl1 −179.78 (10) C6—C4—C3—C2 −179.18 (15)
C3—C2—C1—N1 −0.5 (3) C3—C4—C6—C7 179.37 (15)
C3—C2—C1—Cl1 −179.43 (12) C5—C4—C6—C7 −0.6 (2)
N2—C5—C4—C3 −179.67 (13) C4—C6—C7—C8 −0.1 (2)
N1—C5—C4—C3 0.0 (2) N2—C8—C7—C6 1.1 (2)
N2—C5—C4—C6 0.3 (2) N3—C8—C7—C6 −178.33 (15)
Hydrogen-bond geometry (Å, º)
D—H···A D—H H···A D···A D—H···A
N3—H3A···N2i 0.86 2.12 2.974 (3) 172
