Ethyl 5-[(1H-benzoimidazol-2-yl)amino­carbon­yl]-4-hydr­oxy-2-methyl-6-oxo-1-propyl-1,6-dihydro­pyridine-3-carboxyl­ate–ethanol–methanol (4/2/1)

Svetlana V Shishkina; Oleg V Shishkin; Igor V Ukrainets; Andrei A Tkach; Lina A Grinevich

doi:10.1107/S1600536809026816

. 2009 Jul 25;65(Pt 8):o1984. doi: 10.1107/S1600536809026816

Ethyl 5-[(1H-benzoimidazol-2-yl)aminocarbonyl]-4-hydroxy-2-methyl-6-oxo-1-propyl-1,6-dihydropyridine-3-carboxylate–ethanol–methanol (4/2/1)

Svetlana V Shishkina ^a,^*, Oleg V Shishkin ^a, Igor V Ukrainets ^b, Andrei A Tkach ^b, Lina A Grinevich ^b

PMCID: PMC2977359 PMID: 21583660

Abstract

The asymmetric unit of the title compound, 4C₂₀H₂₂N₄O₅·2C₂H₆O·CH₄O, contains two pyridine-3-carboxylate molecules, one ethanol molecule and one methanol molecule disordered about in a centre of symmetry. The pyridinone ring, the carbamide group and the bicyclic fragment in both independent molecules are planar within 0.03 Å due to the formation of intramolecular O—H⋯O and N—H⋯O hydrogen bonds. The formation of these latter interactions also causes the redistribution of the electron density within the hydroxypyridone fragment, with the result that some bonds are elongated compared with values in the literature and some others are shorter. In the crystal phase, the pyridine-3-carboxylate molecules form layers parallel to (010), which are interlinked through hydrogen bonds mediated by the bridging solvate molecules. A terminal ethyl group in one of the molecules is disordered over two sites of equally occupancy.

Related literature

For general properties of N-acylic derivatives of 2-aminobenzoimidazole, see: Ukrainets et al. (1993 ▶, 2006 ▶). For the geometrical properties of related compounds, see: Bürgi & Dunitz (1994 ▶); Low & Wilson (1983 ▶).

Experimental

Crystal data

4C₂₀H₂₂N₄O₅·2C₂H₆O·CH₄O
M _r = 1717.84
Triclinic,
a = 10.5527 (4) Å
b = 13.9720 (4) Å
c = 16.0242 (5) Å
α = 86.804 (3)°
β = 70.980 (3)°
γ = 78.652 (3)°
V = 2189.90 (12) Å³
Z = 1
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 293 K
0.40 × 0.30 × 0.10 mm

Data collection

Oxford Diffraction Xcalibur3 diffractometer
Absorption correction: none
23866 measured reflections
7499 independent reflections
3785 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.055
wR(F ²) = 0.170
S = 0.89
7499 reflections
596 parameters
9 restraints
H-atom parameters constrained
Δρ_max = 0.44 e Å⁻³
Δρ_min = −0.35 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2005 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2005 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: XP (Bruker, 1998 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809026816/bg2271sup1.cif

e-65-o1984-sup1.cif^{(39.3KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809026816/bg2271Isup2.hkl

e-65-o1984-Isup2.hkl^{(366.9KB, 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
O1A—H1A⋯O3A	0.82	1.77	2.503 (2)	149
O1B—H1B⋯O3B	0.82	1.78	2.508 (2)	148
N2A—H2A⋯O2A	0.86	1.88	2.600 (3)	140
N2B—H2B⋯O2B	0.86	1.88	2.596 (3)	139
N3A—H3A⋯O2ⁱ	0.86	2.34	2.968 (3)	130
N3A—H3A⋯O3A	0.86	2.21	2.710 (3)	117
N3B—H3B⋯O1ⁱⁱ	0.86	2.46	3.106 (6)	132
N3B—H3B⋯O3B	0.86	2.18	2.691 (3)	118
O2—H2⋯N4A	0.82	2.27	2.926 (3)	138
O1—H1⋯N4B	0.82	2.35	3.050 (6)	144

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Symmetry codes: (i) Inline graphic ; (ii) .

supplementary crystallographic information

Comment

N-acylic derivatives of 2-aminobenzoimidazole are considered as potential antithyroid drugs (Ukrainets et al., 1993), for what the structures of these compounds are of particular interest. In the present paper, we report the crystal structure of ethyl-5(1H- benzoimidazol-2-ylcarbamoyl)-4-hydroxy-2-methyl-6-oxo-1-propyl-1,6- dihydropyridine-3-carboxylate (I). The compound exists as a ethanol:methanol solvate in a 4:2:1 ratio. The asymmetric unit contains two molecules (A and B) of I, one ethanol molecule and one methanol molecule located in a centre of symmetry. The pyridinone ring, the carbamide group and the bicyclic fragment in molecules A and B lie in a plane within 0.03 Å due to the formation of many O—H···O, N—H···O intramolecular hydrogen bonds (Table 1, top eight entries). The formation of these hydrogen bonds causes also the redistribution of the electron density within the hydroxypyridone fragment. The O2—C5, O3—C6 and C3—C4 bonds (See Supplementary Material) are elongated as compared with reported value (mean values in the literature: 1.210 Å for the C=O and 1.326 Å for the C—C bond; Bürgi & Dunitz, 1994) and the O1—C3 and C4—C5 bonds are, instead, shorter (mean values in the literature: 1.362 Å and 1.455 Å). Some elongation of the C1—C2 bond and shortening of the C2—C3 bond can be caused, probably, by the strong conjugation between endocyclic double bonds which is typical for the pyridinone ring (Low & Wilson, 1983). The substituent at the C2 atom is turned relatively to the plane of the heterocycle (C1—C2—C17—O4 torsion angle: 47.2 (4) ° in A and 59.3 (4) ° in B). The ethyl group has sp-conformation relatively to the C17—O4 bond (C18—O5—C17—O4 torsion angle: 6.0 (5) Å (A) 7.3 (5) Å (B)). In molecule B the ethyl group is orthogonal to the C17—O5 bond (C17—O5—C18—C19 torsion angle: 84.0 (4) °) while in the molecule A this group is disordered over three positions due to the rotation around the O5—C18 bond with populations 0.50:0.25:0.25 and C17—O5—C18—C19 torsion angle: 175.0 (5) °, 139.3 (9) %A and 92 (1) °, respectively. In the crystal phase the molecules of I form layers parallel to (010). Neighbouring layers are interlinked through H-bonds mediated by the bridging solvate molecules (Table 1, last two entries).

Experimental

A mixture of diethyl 4-hydroxy-2-methyl-6-oxo-1-propyl-1,6-dihydro- pyridine-3,5-dicarboxylate (Ukrainets et al., 2006) (3.11 g, 10.0 mmol), 2-aminobenzimidazole (1.33 g, 10.0 mmol), and DMF (1 ml) was stirred an kept on a metal bath at 160%A C for 5 min. The mixture was cooled, ethanol (30 ml) was added, the mixture was thoroughly mixed and filtered. The amino-ester obtained was washed on the filter with ethanol and dried. Yield 3.58 g (83%). m.p. 154–156%A C.