2,7-Dimethyl-1,8-naphthyridine

Fun, H.-K.; Yeap, C.S.; Das, N.K.; Mahapatra, A.K.; Goswami, S.

doi:10.1107/S1600536809024350

organic compounds

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ISSN: 2056-9890

Volume 65| Part 8| August 2009| Page o1747

doi:10.1107/S1600536809024350

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2,7-Dimethyl-1,8-naphthyridine

Hoong-Kun Fun,^a ^*‡ Chin Sing Yeap,^a § Nirmal Kumar Das,^b Ajit Kumar Mahapatra ^b and Shyamaprosad Goswami ^b

^aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, and ^bDepartment of Chemistry, Bengal Engineering and Science University, Shibpur, Howrah 711 103, India
^*Correspondence e-mail: hkfun@usm.my

(Received 5 June 2009; accepted 24 June 2009; online 4 July 2009)

The asymmetric unit of the title compound, C₁₀H₁₀N₂, contains one half-molecule with the two shared C atoms lying on a twofold rotation axis. The 1,8-naphthyridine is almost planar with a dihedral angle of 0.42 (3)° between the fused pyridine rings. In the crystal, molecules are linked into infinite chains along the c axis by intermolecular C—H⋯N hydrogen bonds, generating R₂²(8) ring motifs. In addition, the crystal structure is further stabilized by C—H⋯π interactions.

Related literature

For applications of naphthyridines, see: Badawneh et al. (2001 ); Hawes et al. (1977 ); Gorecki & Hawes (1977 ). For molecular recognition chemistry of naphthyridines, see: Goswami & Mukherjee (1997 ); Goswami et al. (2001 , 2005 ). For the preparation of 2,7-dimethyl-[1,8]naphthyridine, see: Chandler et al. (1982 ). For hydrogen-bond motifs, see: Bernstein et al. (1995 ). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ).

Experimental

Crystal data

C₁₀H₁₀N₂
M_r = 158.20
Orthorhombic, F d d 2
a = 13.3977 (2) Å
b = 19.3492 (4) Å
c = 6.3089 (1) Å
V = 1635.49 (5) Å³
Z = 8
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 100 K
0.57 × 0.41 × 0.24 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.939, T_max = 0.981
15454 measured reflections
1153 independent reflections
1116 reflections with I > 2σ(I)
R_int = 0.024

Refinement

R[F² > 2σ(F²)] = 0.034
wR(F²) = 0.098
S = 1.09
1153 reflections
57 parameters
1 restraint
H-atom parameters constrained
Δρ_max = 0.51 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C3—H3A⋯N1ⁱ	0.93	2.56	3.4889 (9)	175
C6—H6C⋯Cg1ⁱⁱ	0.96	2.78	3.5742 (8)	140
C6—H6C⋯Cg2ⁱⁱⁱ	0.96	2.78	3.5742 (8)	140
Symmetry codes: (i) x, y, z+1; (ii) $[-x-{\script{3\over 4}}, y+{\script{3\over 4}}, z-{\script{1\over 4}}]$ ; (iii) $[x-{\script{1\over 4}}, -y+{\script{1\over 4}}, z-{\script{1\over 4}}]$ . Cg1 and Cg2 are the centroids of the N1/C1–C5 and C1–C2/C3A–C5A/N1A rings, respectively.

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT; 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 and PLATON (Spek, 2009 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809024350/bq2147sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809024350/bq2147Isup2.hkl

checkCIF report

Comment top

Due to their wide applications in medicine, naphthyridines are one of the most useful group of compounds. They are used as antihypertensives, antitumor agents, immunostimulants and herbicide safeners (Badawneh et al., 2001; Hawes et al., 1977; Gorecki et al., 1977). Naphthyridines are also used as a key molecule in molecular recognition chemistry (Goswami & Mukherjee, 1997; Goswami et al., 2005; 2001; Sheldrick, 2008). We report here the single crystal X-ray structure.

In the title compound (I), (Fig. 1), the C1 and C2 atoms are lying on twofold rotation axis [symmetry code: -x, -y, z]. The dihedral angle between the two pyridine rings is equal to 0.42 (3)° indicating that the 1,8-naphthyridine is almost planar. The molecules are linked together into infinite chains by the intermolecular C3—H3A···N1 hydrogen bonds along the c axis (Fig. 2) generating R₂²(8) ring motifs (Bernstein et al., 1995). The crystal structure is further stabilized by the C—H···π interactions (Table 1).

Related literature top

For applications of naphthyridines, see: Badawneh et al. (2001); Hawes et al. (1977); Gorecki et al. (1977). For molecular recognition chemistry of naphthyridines, see: Goswami & Mukherjee (1997); Goswami et al. (2001, 2005). For preparation of 2,7-dimethyl-[1,8]naphthyridine, see: Chandler et al. (1982). Cg1 and Cg2 are the centroids of the N1/C1–C5 and C1–C2/C3A–C5A/N1A rings, respectively. For hydrogen-bond motifs, see: Bernstein et al. (1995). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).

Experimental top

2,7-dimethyl-[1,8]naphthyridine was prepared according to the literature procedure (Chandler et al., 1982). In a sample bottle, 10 mg of compound was taken and dissolved in CHCl₃ and by slow evaporation the crystals are formed as colorless blocks.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); 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) and PLATON (Spek, 2009).

Figures top

	Fig. 1. The molecular structure of the title compound with atom labels and 50% probability ellipsoids for non-H atoms. Symmetry code: (i) -x, -y, z.
	Fig. 2. The crystal packing of (I), viewed down the a axis, showing the molecules are linked along the c axis. Intermolecular hydrogen bonds are shown in as dashed lines.

2,7-Dimethyl-1,8-naphthyridine top

Crystal data top

C₁₀H₁₀N₂	F(000) = 672
M_r = 158.20	D_x = 1.285 Mg m⁻³
Orthorhombic, Fdd2	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: F 2 -2d	Cell parameters from 9922 reflections
a = 13.3977 (2) Å	θ = 3.0–40.6°
b = 19.3492 (4) Å	µ = 0.08 mm⁻¹
c = 6.3089 (1) Å	T = 100 K
V = 1635.49 (5) Å³	Block, colourless
Z = 8	0.57 × 0.41 × 0.24 mm

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	1153 independent reflections
Radiation source: fine-focus sealed tube	1116 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.024
ϕ and ω scans	θ_max = 37.5°, θ_min = 3.7°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −21→22
T_min = 0.939, T_max = 0.981	k = −32→31
15454 measured reflections	l = −10→10

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)] = 0.034	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.098	H-atom parameters constrained
S = 1.09	w = 1/[σ²(F_o²) + (0.0689P)² + 0.3523P] where P = (F_o² + 2F_c²)/3
1153 reflections	(Δ/σ)_max < 0.001
57 parameters	Δρ_max = 0.51 e Å⁻³
1 restraint	Δρ_min = −0.25 e Å⁻³

Crystal data top

C₁₀H₁₀N₂	V = 1635.49 (5) Å³
M_r = 158.20	Z = 8
Orthorhombic, Fdd2	Mo Kα radiation
a = 13.3977 (2) Å	µ = 0.08 mm⁻¹
b = 19.3492 (4) Å	T = 100 K
c = 6.3089 (1) Å	0.57 × 0.41 × 0.24 mm

Data collection top

Bruker SMART APEXII CCD area-detector diffractometer	1153 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	1116 reflections with I > 2σ(I)
T_min = 0.939, T_max = 0.981	R_int = 0.024
15454 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.034	1 restraint
wR(F²) = 0.098	H-atom parameters constrained
S = 1.09	Δρ_max = 0.51 e Å⁻³
1153 reflections	Δρ_min = −0.25 e Å⁻³
57 parameters

Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1)K.

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 > 2sigma(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	0.01020 (4)	0.05928 (3)	0.32666 (9)	0.01333 (14)
C1	0.0000	0.0000	0.44228 (13)	0.01141 (18)
C2	0.0000	0.0000	0.66711 (15)	0.01275 (18)
C3	0.01175 (6)	0.06389 (4)	0.77384 (11)	0.01521 (15)
H3A	0.0129	0.0658	0.9211	0.018*
C4	0.02138 (6)	0.12274 (4)	0.65545 (14)	0.01597 (16)
H4A	0.0289	0.1653	0.7218	0.019*
C5	0.01984 (5)	0.11846 (4)	0.42997 (11)	0.01352 (15)
C6	0.02718 (6)	0.18360 (4)	0.30155 (15)	0.01878 (15)
H6A	0.0381	0.1721	0.1554	0.028*
H6B	0.0819	0.2110	0.3525	0.028*
H6C	−0.0338	0.2094	0.3147	0.028*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
N1	0.0165 (3)	0.0124 (3)	0.0111 (3)	−0.00003 (19)	−0.00022 (18)	0.00128 (16)
C1	0.0132 (4)	0.0123 (4)	0.0087 (4)	0.0005 (3)	0.000	0.000
C2	0.0148 (4)	0.0138 (4)	0.0096 (4)	−0.0002 (3)	0.000	0.000
C3	0.0189 (3)	0.0159 (3)	0.0108 (3)	−0.0010 (2)	0.00012 (19)	−0.0019 (2)
C4	0.0196 (4)	0.0138 (3)	0.0144 (3)	−0.0006 (2)	0.0004 (2)	−0.0025 (2)
C5	0.0150 (3)	0.0124 (3)	0.0131 (3)	0.0001 (2)	−0.0002 (2)	0.0010 (2)
C6	0.0229 (3)	0.0137 (3)	0.0197 (3)	−0.0013 (2)	−0.0009 (3)	0.0038 (2)

Geometric parameters (Å, º) top

N1—C5	1.3238 (8)	C3—H3A	0.9300
N1—C1	1.3662 (7)	C4—C5	1.4251 (11)
C1—N1ⁱ	1.3662 (7)	C4—H4A	0.9300
C1—C2	1.4184 (13)	C5—C6	1.5017 (10)
C2—C3ⁱ	1.4165 (9)	C6—H6A	0.9600
C2—C3	1.4165 (9)	C6—H6B	0.9600
C3—C4	1.3678 (10)	C6—H6C	0.9600

C5—N1—C1	118.23 (6)	C3—C4—H4A	120.2
N1ⁱ—C1—N1	115.46 (7)	C5—C4—H4A	120.2
N1ⁱ—C1—C2	122.27 (4)	N1—C5—C4	122.90 (7)
N1—C1—C2	122.27 (4)	N1—C5—C6	117.83 (6)
C3ⁱ—C2—C3	123.23 (9)	C4—C5—C6	119.26 (7)
C3ⁱ—C2—C1	118.39 (4)	C5—C6—H6A	109.5
C3—C2—C1	118.38 (4)	C5—C6—H6B	109.5
C4—C3—C2	118.51 (7)	H6A—C6—H6B	109.5
C4—C3—H3A	120.7	C5—C6—H6C	109.5
C2—C3—H3A	120.7	H6A—C6—H6C	109.5
C3—C4—C5	119.69 (7)	H6B—C6—H6C	109.5

C5—N1—C1—N1ⁱ	179.65 (7)	C1—C2—C3—C4	0.76 (8)
C5—N1—C1—C2	−0.35 (7)	C2—C3—C4—C5	−0.28 (11)
N1ⁱ—C1—C2—C3ⁱ	−0.46 (5)	C1—N1—C5—C4	0.88 (11)
N1—C1—C2—C3ⁱ	179.54 (5)	C1—N1—C5—C6	−177.77 (5)
N1ⁱ—C1—C2—C3	179.54 (5)	C3—C4—C5—N1	−0.57 (13)
N1—C1—C2—C3	−0.46 (5)	C3—C4—C5—C6	178.06 (6)
C3ⁱ—C2—C3—C4	−179.25 (8)

Symmetry code: (i) −x, −y, z.

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···N1ⁱⁱ	0.93	2.56	3.4889 (9)	175
C6—H6C···Cg1ⁱⁱⁱ	0.96	2.78	3.5742 (8)	140
C6—H6C···Cg2^iv	0.96	2.78	3.5742 (8)	140

Symmetry codes: (ii) x, y, z+1; (iii) −x−3/4, y+3/4, z−1/4; (iv) x−1/4, −y+1/4, z−1/4.

Experimental details

Crystal data
Chemical formula	C₁₀H₁₀N₂
M_r	158.20
Crystal system, space group	Orthorhombic, Fdd2
Temperature (K)	100
a, b, c (Å)	13.3977 (2), 19.3492 (4), 6.3089 (1)
V (Å³)	1635.49 (5)
Z	8
Radiation type	Mo Kα
µ (mm⁻¹)	0.08
Crystal size (mm)	0.57 × 0.41 × 0.24

Data collection
Diffractometer	Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.939, 0.981
No. of measured, independent and observed [I > 2σ(I)] reflections	15454, 1153, 1116
R_int	0.024
(sin θ/λ)_max (Å⁻¹)	0.856

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.034, 0.098, 1.09
No. of reflections	1153
No. of parameters	57
No. of restraints	1
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.51, −0.25

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C3—H3A···N1ⁱ	0.9300	2.5600	3.4889 (9)	175.00
C6—H6C···Cg1ⁱⁱ	0.9600	2.7800	3.5742 (8)	140.00
C6—H6C···Cg2ⁱⁱⁱ	0.9600	2.7800	3.5742 (8)	140.00

Symmetry codes: (i) x, y, z+1; (ii) −x−3/4, y+3/4, z−1/4; (iii) x−1/4, −y+1/4, z−1/4.

Footnotes

‡Thomson Reuters ResearcherID: A-3561-2009.

§Thomson Reuters ResearcherID: A-5523-2009.

Acknowledgements

HKF thanks Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012. CSY thanks the Malaysian Government and Universiti Sains Malaysia for the award of the post of Research Officer under the Science Fund grant No. 305/PFIZIK/613312. SG thanks the DST (SR/S1/OC-13/2005), Government of India, for financial support. NKD thanks the UGC, Government of India, for a research fellowship.

References

Badawneh, M., Ferrarini, P. L., Calderone, V., Manera, C., Martinotti, E., Mori, C., Saccomanni, G. & Testai, L. (2001). Eur. J. Med. Chem. 36, 925–934. Web of Science CrossRef PubMed CAS Google Scholar
Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555–1573. CrossRef CAS Web of Science Google Scholar
Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Chandler, C. J., Deady, L. W., Reiss, J. A. & Tzimos, V. J. (1982). J. Heterocycl. Chem. 19, 1017–1019. CrossRef CAS Google Scholar
Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105–107. CrossRef CAS Web of Science IUCr Journals Google Scholar
Gorecki, D. K. J. & Hawes, E. M. (1977). J. Med. Chem. 20, 124–128. CrossRef CAS Web of Science Google Scholar
Goswami, S., Ghosh, K. & Mukherjee, R. (2001). Tetrahedron, 57, 4987–4993. Web of Science CrossRef CAS Google Scholar
Goswami, S. & Mukherjee, R. (1997). Tetrahedron Lett. 38, 1619–1621. CrossRef CAS Web of Science Google Scholar
Goswami, S., Mukherjee, R., Mukherjee, S., Jana, S., Maity, A. C. & Adak, A. K. (2005). Molecules, 10, 929–934. Web of Science CrossRef PubMed CAS Google Scholar
Hawes, E. M., Gorecki, D. K. J. & Gedir, G. G. (1977). J. Med. Chem. 20, 838–841. CrossRef CAS PubMed Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Spek, A. L. (2009). Acta Cryst. D65, 148–155. Web of Science CrossRef CAS IUCr Journals Google Scholar