2-Amino­pyridinium 5-(5-chloro-2,4-dinitro­phen­yl)-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetra­hydro­pyrimidin-6-olate

Vaduganathan Manickkam; Doraisamyraja Kalaivani

doi:10.1107/S1600536811049518

. 2011 Nov 30;67(Pt 12):o3475. doi: 10.1107/S1600536811049518

2-Aminopyridinium 5-(5-chloro-2,4-dinitrophenyl)-1,3-dimethyl-2,4-dioxo-1,2,3,4-tetrahydropyrimidin-6-olate

Vaduganathan Manickkam ^a, Doraisamyraja Kalaivani ^a,^*

PMCID: PMC3239101 PMID: 22199949

Abstract

In the title molecular salt, C₅H₇N₂ ⁺·C₁₂H₈ClN₄O₇ ⁻, the dihedral angle between the aromatic rings of the anion is 51.88 (6)°. One of the nitro groups is disordered over two orientations in a 0.710 (6):0.290 (6) ratio. In the crystal, the cations and anions are linked by N—H⋯O hydrogen bonds, generating infinite ribbons extending along [100] which incorporate R ₄ ⁴(22) ring motifs. Weak C—H⋯O interactions also occur.

Related literature

For our previous work in this area and background to barbiturate drugs, see: Kalaivani & Buvaneswari (2010 ▶); Kalaivani et al. (2008 ▶). For a related structure, see: Swamy et al. (2008 ▶).

Experimental

Crystal data

C₅H₇N₂ ⁺·C₁₂H₈ClN₄O₇ ⁻
M _r = 450.80
Monoclinic,
a = 8.578 (5) Å
b = 11.229 (5) Å
c = 19.952 (5) Å
β = 94.952 (5)°
V = 1914.7 (15) Å³
Z = 4
Mo Kα radiation
μ = 0.26 mm⁻¹
T = 293 K
0.30 × 0.20 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.882, T _max = 0.941
19182 measured reflections
4053 independent reflections
2996 reflections with I > 2σ(I)
R _int = 0.032

Refinement

R[F ² > 2σ(F ²)] = 0.044
wR(F ²) = 0.124
S = 1.06
4053 reflections
315 parameters
28 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.38 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SIR92 (Altomare et al., 1993 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536811049518/hb6510sup1.cif

e-67-o3475-sup1.cif^{(22.1KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536811049518/hb6510Isup2.hkl

e-67-o3475-Isup2.hkl^{(198.7KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811049518/hb6510Isup3.cml

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
N5—H5A⋯O1ⁱ	0.856 (19)	1.882 (19)	2.730 (3)	170.8 (19)
N6—H6A⋯O2ⁱⁱ	0.85 (2)	1.976 (19)	2.805 (3)	163 (3)
N6—H6B⋯O3	0.85 (2)	2.12 (2)	2.883 (3)	150 (2)
C9—H9⋯O2ⁱⁱⁱ	0.93	2.51	3.097 (3)	121
C9—H9⋯O7^iv	0.93	2.57	3.285 (3)	134
C11—H11C⋯O5^v	0.96	2.59	3.241 (4)	126

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

Acknowledgments

The authors are thankful to the SAIF, IIT Madras, for the data collection.

supplementary crystallographic information

Comment

As part of our ongoing studies of water soluble barbiturates (Kalaivani et al.,2008; Kalaivani & Buvaneswari, 2010), we now report the title barbiturate salt, (I), which has reasonable solubility in polar solvents (water 0.5 g/100 ml; ethanol 1.3 g/100 ml; DMSO 10.1 g/100 ml). As single-crystal X-ray diffraction studies help to understand drug-target interaction (Swamy et al., 2008), the present study may probably help to understand the mechanism of action of barbiturates with biological systems. The cation and anion parts of the title molecule are shown in the Scheme. Fig.1 and Fig.2 are the ORTEP and packing views of the title molecular salt respectively. The dihedral angle between the chlorodinitrophenyl ring and 1,3-dimethylbarbiturate ring is observed to be 51.88 (6)°. The nitro group at the para position is disordered over two positions with percentage of occupancy 71 and 29.

Experimental

1,3-Dichloro-4,6-dinitrobenzene (1.18 g, 0.005 mol) was dissolved in 20 ml of absolute alcohol. To this, 0.78 g (0.005 mol) of 1,3-dimethylbarbituric acid was added and the temperature of the mixture was raised to 50°C. To this mixture 1.88 g (0.02 mol) of 2-aminopyridine in 20 ml of absolute alcohol was added. This mixture was shaken well for 2–5 h and kept as such at 25°C for 2 days. On standing, crystals came out from the solution which were filtered and dried. The dry orange colored crystals obtained were powdered well, washed with absolute alcohol and dry ether and then recrystallized from absolute alcohol (yield: 70%; m.pt: 233°C (decomposes at its melting point). Colourless blocks of (I) were obtained by slow evaporation of ethanol at room temperature.