N,N-Diethyl­anilinium 5-(2,4-dinitro­phen­yl)-2,6-dioxo-1,2,3,6-tetra­hydro­pyrimidin-4-olate

Doraisamyraja Kalaivani; Govindan Mangaiyarkarasi

doi:10.1107/S160053681204874X

. 2012 Dec 5;69(Pt 1):o3–o4. doi: 10.1107/S160053681204874X

N,N-Diethylanilinium 5-(2,4-dinitrophenyl)-2,6-dioxo-1,2,3,6-tetrahydropyrimidin-4-olate

Doraisamyraja Kalaivani ^a,^*, Govindan Mangaiyarkarasi ^a

PMCID: PMC3588294 PMID: 23476417

Abstract

The asymmetric unit of the title molecular salt, C₁₀H₁₆N⁺·C₁₀H₅N₄O₇ ⁻ (trivial name: N,N-diethylanilinium 2,4-dinitrophenylbarbiturate), comprises two anion–cation units. In the anions, the dinitrophenyl ring and the mean plane of the barbiturate ring [planar to within 0.011 (2) and 0.023 (2) Å in the two anions] are inclined to one another by 41.47 (9) and 45.12 (9)°. In the crystal, the anions are linked via strong N—H⋯O hydrogen bonds, forming chains propagating along [10-1]. Within the chains, adjacent inversion-related anionic barbiturate entities are joined through R ₂ ²(8) ring motifs. The cations are linked to the chains via N—H⋯O hydrogen bonds. The chains are linked via a number of C—H⋯O interactions, forming a three-dimensional structure.

Related literature

For the crystal structures of related barbiturates, see: Kalaivani & Malarvizhi (2009 ▶); Buvaneswari & Kalaivani (2011a ▶,b ▶); Kalaivani et al. (2012 ▶); Babykala & Kalaivani (2012 ▶). For the biological activity of barbiturates, see: Hueso et al. (2003 ▶); Kalaivani et al. (2008 ▶); Tripathi (2009 ▶); Kalaivani & Buvaneswari (2010 ▶).

Experimental

Crystal data

C₁₀H₁₆N⁺·C₁₀H₅N₄O₇ ⁻
M _r = 443.42
Triclinic,
a = 8.7260 (2) Å
b = 14.2930 (3) Å
c = 18.1080 (5) Å
α = 106.712 (1)°
β = 96.490 (1)°
γ = 97.667 (1)°
V = 2116.27 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.11 mm⁻¹
T = 293 K
0.30 × 0.30 × 0.25 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.944, T _max = 0.996
36083 measured reflections
7482 independent reflections
5563 reflections with I > 2σ(I)
R _int = 0.029

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.122
S = 1.02
7482 reflections
601 parameters
6 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.39 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: APEX2 and SAINT (Bruker, 2004 ▶); data reduction: SAINT and XPREP (Bruker, 2004 ▶); 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, 2012 ▶) and Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Click here for additional data file.^{(35.3KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S160053681204874X/su2535sup1.cif

e-69-000o3-sup1.cif^{(35.3KB, cif)}

Click here for additional data file.^{(366.1KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681204874X/su2535Isup2.hkl

e-69-000o3-Isup2.hkl^{(366.1KB, hkl)}

Click here for additional data file.^{(8.1KB, cml)}

Supplementary material file. DOI: 10.1107/S160053681204874X/su2535Isup3.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
N3—H3A⋯O7ⁱ	0.89 (2)	2.00 (2)	2.878 (2)	172 (2)
N4—H4A⋯O14ⁱⁱ	0.87 (2)	1.93 (2)	2.802 (2)	172 (2)
N7—H7A⋯O13ⁱⁱⁱ	0.88 (2)	2.06 (2)	2.931 (2)	175 (2)
N8—H8A⋯O6^iv	0.89 (2)	1.98 (2)	2.852 (2)	164 (2)
N9—H9A⋯O12	0.90 (2)	1.83 (2)	2.726 (2)	176 (1)
N10—H10A⋯O5^v	0.92 (2)	1.69 (2)	2.598 (3)	166 (2)
C12—H12⋯O4^vi	0.93	2.52	3.451 (3)	174
C26—H26⋯O12	0.93	2.59	3.272 (3)	131
C26—H26⋯O13ⁱⁱⁱ	0.93	2.56	3.281 (3)	135
C29—H29B⋯O11	0.97	2.57	3.215 (3)	124
C38—H38A⋯O7ⁱ	0.96	2.52	3.484 (3)	177

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

Acknowledgments

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

supplementary crystallographic information

Comment

The methylene group of barbituric acid [a pyrimidine derivative] is flanked on both sides by the electron-withdrawing carbonyl groups which makes the hydrogen atoms highly acidic. These acidic H atoms have been targeted by our group in the preparation of a number of extraordinarily stable barbiturates (Kalaivani & Malarvizhi, 2009; Buvaneswari & Kalaivani, 2011a; Kalaivani et al., 2012; Babykala & Kalaivani, 2012). We have reported on the crystal structure of a barbiturate related to the title molecular salt but derived from 1-chloro-2,4,6-trinitrobenzene (TNCB) and barbituric acid in the presence of N,N-diethylaniline (I) (Buvaneswari & Kalaivani, 2011b). Herein we report on the crystal structure of the new title molecular salt obtained from 1-chloro-2,4-dinitrobenzene (DNCB) and barbituric acid in the presence of N,N-diethylaniline, (II).

Unlike the asymmetric unit of the related reported barbiturate (I), which comprises of only one anion and cation moieties, the asymmetric unit of the barbiturate of the title compound (II) is composed of two cations and two anions (Fig. 1). Contrary to the barbiturate of TNCB (I), which crystallized in the monoclinic space group P2₁/c, the title compound (II) crystallized in the triclinic space group P1.

In the crystal of (II), the anions are linked via N—H···O hydrogen bonds (Table 1 and Fig. 2), forming chains along direction [1 0 -1]. This linkage and the R₂²(8) ring motifs formed between inversion-related barbiturate residues contributes considerably to the extraordinary stability of the title molecular salt. The cations are linked to the chains via N-H···O hydrogen bonds (Table 1 and Fig. 2). There are C-H···O interactions present (Table 1) but no π-π stacking interactions between the N,N-diethylaniline and 2,4-dinitrophenyl ring moieties.

As barbiturates are employed in the treatment of neurological disorders (Hueso et al., 2003; Kalaivani et al., 2008; Tripathi, 2009; Kalaivani & Buvaneswari, 2010), the non-bonding interactions of the present investigation may help to understand the mechanistic aspects of the physiological action of barbiturates.

Experimental

Analytical grade 1-chloro-2,4-dinitrobenzene (2.02 g, 0.01 mol) was dissolved in 20 ml of absolute alcohol. Barbituric acid (1.28 g, 0.01 mol) was also dissolved in 30 ml of absolute alcohol separately. These two solutions were then mixed well. To this mixture, ca. 4 ml of N,N-diethylaniine (0.03 mol) was added and shaken well for 5–6 hrs. The slightly turbid solution obtained was filtered and kept as such at room temperature. After a period of four weeks, dark shiny maroon red coloured crystals of the title salt crystallized out from this solution. The crystals were filtered and washed well with 30 ml of dry ether. The crystals were then powdered and washed with 5 ml of absolute alcohol to remove the unreacted reactants and finally with 25 ml of dry ether. The pure powder was then recrystallized from hot ethanol (M.p: 481 K; yield: 80%). Good quality single crystals, suitable for X-ray diffraction studies, were obtained by slow evaporation of a solution in ethanol at room temperature. The crystals obtained were non-hygroscopic and extraordinarily stable at room temperature.