2-Amino-5-chloro­pyridine–benzoic acid (1/1)

Madhukar Hemamalini; Hoong-Kun Fun

doi:10.1107/S1600536810004447

. 2010 Feb 10;66(Pt 3):o578. doi: 10.1107/S1600536810004447

2-Amino-5-chloropyridine–benzoic acid (1/1)

Madhukar Hemamalini ^a, Hoong-Kun Fun ^a,^*,^‡

PMCID: PMC2983607 PMID: 21580345

Abstract

In the title compound, C₅H₅ClN₂·C₇H₆O₂, the carboxyl group of the benzoic acid molecule is twisted away from the attached ring by 14.22 (7)°. In the crystal, the 2-amino-5-chloropyridine molecules interact with the carboxyl groups of benzoic acid molecules through N—H⋯O and O—H⋯N hydrogen bonds, forming cyclic R ₂ ²(8) hydrogen-bonded motifs, and linking the molecules into chains parallel to the [001] direction. Neighbouring 2-amino-5-chloropyridine molecules are also centrosymmetrically paired through C—H⋯Cl hydrogen bonds, forming another R ₂ ²(8) motif. The crystal structure is further stabilized by weak C—H⋯O hydrogen bonds.

Related literature

For background to the chemistry of substituted pyridines, see: Pozharski et al. (1997 ▶); Katritzky et al. (1996 ▶); For details of hydrogen bonding, see: Jeffrey & Saenger (1991 ▶); Jeffrey (1997 ▶); Scheiner (1997 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶); Lynch & Jones (2004 ▶). For reference bond-length data, see: Allen et al. (1987 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶).

Experimental

Crystal data

C₅H₅ClN₂·C₇H₆O₂
M _r = 250.68
Monoclinic,
a = 17.6114 (19) Å
b = 5.3442 (6) Å
c = 12.4774 (13) Å
β = 100.161 (2)°
V = 1155.9 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.32 mm⁻¹
T = 100 K
0.55 × 0.25 × 0.07 mm

Data collection

Bruker SMART APEX DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.844, T _max = 0.979
11852 measured reflections
3331 independent reflections
2802 reflections with > 2(I)
R _int = 0.025

Refinement

R[F ² > 2σ(F ²)] = 0.033
wR(F ²) = 0.111
S = 1.12
3331 reflections
198 parameters
All H-atom parameters refined
Δρ_max = 0.46 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); 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 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810004447/wn2376sup1.cif

e-66-0o578-sup1.cif^{(16.7KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810004447/wn2376Isup2.hkl

e-66-0o578-Isup2.hkl^{(163.4KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O2—H1O2⋯N1ⁱ	0.98 (2)	1.65 (2)	2.629 (1)	175 (2)
N2—H1N2⋯O1ⁱⁱ	0.88 (2)	2.04 (2)	2.898 (2)	165.4 (18)
N2—H2N2⋯O2ⁱⁱⁱ	0.88 (2)	2.37 (2)	3.231 (2)	165.8 (17)
C3—H3⋯Cl1^iv	0.99 (2)	2.82 (2)	3.780 (2)	163.4 (16)
C6—H6⋯O1^v	0.91 (2)	2.58 (2)	3.095 (2)	116.3 (15)

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Symmetry codes: (i) Inline graphic ; (ii) ; (iii) ; (iv) ; (v) .

Acknowledgments

MH and HKF thank the Malaysian Government and Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012. MH thanks Universiti Sains Malaysia for a post-doctoral research fellowship.

supplementary crystallographic information

Comment

Pyridine and its derivatives play an important role in heterocyclic chemistry (Pozharski et al., 1997; Katritzky et al., 1996). Pyridine and its substituted derivatives are often involved in hydrogen-bond interactions (Jeffrey & Saenger, 1991; Jeffrey, 1997; Scheiner, 1997). The adducts of carboxylic acids with the 2-aminoheterocylic ring system form a graph-set motif R₂²(8) (Lynch & Jones, 2004). In the present study, the hydrogen-bonding patterns in the 2-amino-5-chloropyridine benzoic acid (1/1) cocrystal, are investigated.

The asymmetric unit (Fig. 1), contains one 2-amino-5-chloropyridine molecule and one benzoic acid molecule. The 2-amino-5-chloropyridine molecule is planar, with a maximum deviation of 0.002 (1) Å for atom N1. The carboxyl group of the benzoic acid molecule is twisted away from the attached ring by 14.22 (7)° . The bond lengths (Allen et al., 1987) and angles are normal.

In the crystal packing (Fig. 2), the 2-amino-5-chloropyridine molecules interact with the carboxyl group of benzoic acid molecules through N—H···O and O—H···N hydrogen bonds, forming a cyclic hydrogen-bonded motif R₂²(8) (Bernstein et al., 1995), and linking the molecules into chains parallel to the [001] direction. Neighbouring 2-amino-5-chloropyridine molecules are also centrosymmetrically paired through C—H···Cl hydrogen bonds, forming another R₂²(8) motif. The crystal structure is further stabilized by weak C6—H6···O1 (Table 1) hydrogen bonds.

Experimental

A hot methanol solution (20 ml) of 2-amino-5-chloropyridine (65 mg, Aldrich) and benzoic acid (61 mg, Merck) were mixed and warmed over a heating magnetic stirrer for a few minutes. The resulting solution was allowed to cool slowly at room temperature and crystals of the title compound appeared after a few days.