Bis(2,6-diamino-4-chloro­pyrimidin-1-ium) fumarate

Kaliyaperumal Thanigaimani; Nuridayanti Che Khalib; Abbas Farhadikoutenaei; Suhana Arshad; Ibrahim Abdul Razak

doi:10.1107/S1600536812045308

. 2012 Nov 10;68(Pt 12):o3321–o3322. doi: 10.1107/S1600536812045308

Bis(2,6-diamino-4-chloropyrimidin-1-ium) fumarate

Kaliyaperumal Thanigaimani ^a, Nuridayanti Che Khalib ^a, Abbas Farhadikoutenaei ^a, Suhana Arshad ^a, Ibrahim Abdul Razak ^a,^*,^‡

PMCID: PMC3588928 PMID: 23476164

Abstract

In the title salt, 2C₄H₆ClN₄ ⁺·C₄H₂O₄ ²⁻, the complete fumarate dianion is generated by crystallographic inversion symmetry. The cation is essentially planar, with a maximum deviation of 0.018 (1) Å. In the anion, the carboxylate group is twisted slightly away from the attached plane, the dihedral angle between the carboxylate and (E)-but-2-ene planes being 12.78 (13)°. In the crystal, the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms of the anion via a pair of N—H⋯O hydrogen bonds, forming an R ₂ ²(8) ring motif. In addition, another type of R ₂ ²(8) motif is formed by centrosymmetrically related pyrimidinium cations via N—H⋯N hydrogen bonds. These two combined motifs form a heterotetramer. The crystal structure is further stabilized by stong N—H⋯O, N—H⋯Cl and weak C—H⋯O hydrogen bonds, resulting a three-dimensional network.

Related literature

For applications of pyrimidine derivatives, see: Condon et al. (1993 ▶); Maeno et al. (1990 ▶); Gilchrist (1997 ▶). For details of fumaric acid, see: Batchelor et al. (2000 ▶). For hydrogen-bonded synthons, see: Thakur & Desiraju (2008 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). For bond-length data, see: Allen et al. (1987 ▶). For stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 ▶). graphic file with name e-68-o3321-scheme1.jpg

Experimental

Crystal data

C₄H₆ClN₄ ⁺·0.5C₄H₂O₄ ²⁻
M _r = 202.61
Monoclinic,
a = 5.4478 (7) Å
b = 10.5187 (14) Å
c = 14.8171 (18) Å
β = 100.990 (4)°
V = 833.50 (18) Å³
Z = 4
Mo Kα radiation
μ = 0.43 mm⁻¹
T = 100 K
0.71 × 0.31 × 0.17 mm

Data collection

Bruker SMART APEXII DUO CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.749, T _max = 0.931
9206 measured reflections
2984 independent reflections
2708 reflections with I > 2σ(I)
R _int = 0.033

Refinement

R[F ² > 2σ(F ²)] = 0.042
wR(F ²) = 0.127
S = 1.08
2984 reflections
138 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.78 e Å⁻³
Δρ_min = −0.78 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

Click here for additional data file.^{(19.3KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812045308/rz5019sup1.cif

e-68-o3321-sup1.cif^{(19.3KB, cif)}

Click here for additional data file.^{(146.5KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812045308/rz5019Isup2.hkl

e-68-o3321-Isup2.hkl^{(146.5KB, hkl)}

Click here for additional data file.^{(6.5KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812045308/rz5019Isup3.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
N2—H1⋯O2ⁱ	0.86 (1)	1.69 (1)	2.5281 (14)	165 (3)
N3—H2⋯O1ⁱ	0.81 (2)	2.12 (2)	2.9233 (15)	168 (2)
N3—H3⋯N1ⁱⁱ	0.85 (2)	2.15 (2)	3.0014 (16)	176 (2)
N4—H4⋯O1ⁱⁱⁱ	0.78 (2)	2.08 (2)	2.8307 (16)	161 (2)
N4—H5⋯Cl1^iv	0.77 (2)	2.78 (2)	3.3671 (13)	135.0 (19)
N4—H5⋯O2ⁱ	0.77 (2)	2.56 (2)	3.1458 (15)	134.2 (19)
C3—H3A⋯O2^v	0.95	2.39	3.3085 (16)	162

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

Acknowledgments

The authors thank the Malaysian Government and Universiti Sains Malaysia (USM) for the research facilities and Fundamental Research Grant Scheme (FRGS) No. 203/PFIZIK/6711171 to conduct this work. KT thanks The Academy of Sciences for the Developing World and USM for a TWAS–USM fellowship.

supplementary crystallographic information

Comment

Pyrimidine derivatives are very important molecules in biology and have many application in the areas of pesticide and pharmaceutical agents (Condon et al., 1993). For example, imazosulfuron, ethirmol and mepanipyrim have been commercialized as agrochemicals (Maeno et al., 1990). Pyrimidine derivatives have also been developed as antiviral agents, such as AZT, which is the most widely-used anti-AIDS drug (Gilchrist, 1997). Fumaric acid is among the organic compounds widely found in nature, and is a key intermediate in the biosynthesis of organic acids. Fumaric acid is of interest since it is known to form supramolecular assemblies with N-aromatic complexes (Batchelor et al., 2000). In order to study some interesting hydrogen bonding interactions, the synthesis and structure of the title compound is presented here.

The asymmetric unit of title compound (Fig. 1), consists of a 2,6-diamino-4-chloropyrimidinium cation and a half of a fumarate dianion where the complete fumarate dianion is generated by crystallographic inversion symmetry (-x + 1, -y + 1, -z + 1). In the 2,6-diamino-4-chloropyridinium cation, protonatation of N1 atom has lead to a slight increase in the C1—N2—C2 angle (120.34 (10)°). The 2,6-diamino-4-chloropyridinium cation is essentially planar, with a maximum deviation of 0.018 (1) Å for atom C3. In the fumarate dianion, C5/C6/C5A/C6A plane makes a dihedral angle of 81.89 (6)° with 2,6-diamino-4-chloropyridinium cation. In the anion, the carboxylate group is twisted slightly away from the attached plane; the dihedral angle between the C5/C6/C5A/C6A and O1/O2/C5/C6 planes is 12.78 (13)°. The bond lengths (Allen et al., 1987) and angles are normal.

In the crystal structure (Fig. 2), the protonated N atom and the 2-amino group of the cation are hydrogen bonded to the carboxylate O atoms of the anion via a pair of N—H···O hydrogen bonds, forming R₂²(8) (Bernstein et al., 1995) ring motifs. In addition, another type of R₂²(8) motif is formed by centrosymmetrically related pyrimidinium cation through a pair of N3—H3···N1ⁱⁱⁱ hydrogen bonds (symmetry codes in Table 1). These two different motifs generate a linear heterotetrameric unit known to be one of the most stable synthons (Thakur & Desiraju, 2008). One of the O atoms of the carboxylate group acts as an acceptors of bifurcated N2—H1···O2ⁱⁱ and N4—H5···O2ⁱⁱ hydrogen bonds (symmetry codes in Table 1). The crystal structure is further stabilized by strong N4—H4···O1^iv, N4—H5···Cl1^V and weak C3—H3A···O2ⁱ hydrogen bonds (symmetry codes in Table 1), resulting in a three-dimensional network.

Experimental

Hot methanol solutions (20 ml) of 2,6-diamino-4-chloropyrimidine (36 mg, Aldrich) and fumaric acid (29 mg, Merck) were mixed and warmed over a heating magnetic stirrer hotplate 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.