n-Butyl 2-(3-chloro-1,2-dihydro­pyrazin-2-yl­idene)-2-cyano­acetate

Stefańska, A.; Ossowski, T.; Ponikiewski, Ł.

doi:10.1107/S1600536809031870

organic compounds

CRYSTALLOGRAPHIC
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ISSN: 2056-9890

Volume 65| Part 9| September 2009| Pages o2157-o2158

doi:10.1107/S1600536809031870

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n-Butyl 2-(3-chloro-1,2-dihydropyrazin-2-ylidene)-2-cyanoacetate

Anita Stefańska,^a Tadeusz Ossowski ^a and Łukasz Ponikiewski ^b ^*

^aFaculty of Chemistry, University of Gdańsk, Sobieskiego 18/19, Gdańsk PL 80952, Poland, and ^bFaculty of Chemistry, Gdańsk University Of Techology, Narutowicza 11/12, Gdańsk PL 80233, Poland
^*Correspondence e-mail: lukas_ponikiewski@vp.pl

(Received 13 July 2009; accepted 12 August 2009; online 15 August 2009)

The title compound, C₁₁H₁₂ClN₃O₂, is essentially planar except for the n-butoxy group [r.m.s. deviation from the least-squares plane = 0.0131 (1) Å for 11 non-H atoms]. An intramolecular N—H⋯O interaction results in the formation of an S(6) ring. The n-butoxy chain in the molecule is disordered over two sets of sites of equal occupancy.

Related literature

For applications of this class of compounds, see: Matter et al. (2005); Kaliszan et al. (1985 ); Petrusewicz et al. (1992 , 1993 , 1995 ). For pyrazinyl–pyrazylidene tautomerism, see: Pilarski et al. (1984 ). For related structures, see: Vishweshwar et al. (2000 ); Wardell et al. (2006 ). For the synthesis, see: Pilarski & Foks (1981 , 1982 ).

Experimental

Crystal data

C₁₁H₁₂ClN₃O₂
M_r = 253.69
Monoclinic, C c
a = 4.918 (3) Å
b = 25.642 (7) Å
c = 10.573 (4) Å
β = 95.80 (3)°
V = 1326.7 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.28 mm⁻¹
T = 120 K
0.57 × 0.11 × 0.07 mm

Data collection

Oxford Diffraction KM-4/Xcalibur diffractometer with a Sapphire2 (large Be window) detector
Absorption correction: Gaussian (CrysAlis Pro; Oxford Diffraction, 2007 $[Oxford Diffraction (2007). CrysAlis Pro. Oxford Diffraction Ltd, Yarnton, England.]$ ) T_min = 0.923, T_max = 0.987
4629 measured reflections
1687 independent reflections
1219 reflections with I > 2σ(I)
R_int = 0.034

Refinement

R[F² > 2σ(F²)] = 0.047
wR(F²) = 0.156
S = 1.04
1687 reflections
154 parameters
1 restraint
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.24 e Å⁻³
Δρ_min = −0.23 e Å⁻³
Absolute structure: Flack (1983 ), 466 Friedel pairs
Flack parameter: 0.05 (18)

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N2—H2B⋯O1	0.87 (2)	1.96 (5)	2.632 (6)	133 (6)

Data collection: CrysAlis CCD (Oxford Diffraction, 2006 $[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]$ ); cell refinement: CrysAlis RED (Oxford Diffraction, 2006 $[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]$ ); data reduction: CrysAlis RED (Oxford Diffraction, 2006 $[Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England.]$ ); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ); software used to prepare material for publication: WinGX (Farrugia, 1999 ).

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536809031870/ng2612sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809031870/ng2612Isup2.hkl

checkCIF report

Comment top

Heterocyclic compounds with active methylene moiety are known to have antiinflamatory (Petrusewicz et al., 1995), analgesic (Kaliszan et al., 1985) and large number of other pharmacological activities (Petrusewicz et al., 1992). Numerous scientific publications confirm that pyrazine derivatives, obtained by nucleophilic substitution of chlorine atom in the pyrazine ring system with active methylene compound, posses above mentioned activity. Some of pyrazine C—H and N—H acids also demonstrated antithrombotic and antiplatelet activity (Petrusewicz et al., 1993).

Such pharmacological activity (in group CH– andNH– acids) is possibly the result of acid character of particle and their structure, as in case of well known inhibitors of cyclooxygenase (Petrusewicz et al., 1993). Structural analysis of pyrazine-acetonitrile derivatives shows pyrazinyl-pyrazylidene tautomerism (Pilarski et al., 1984) but crystal of 2-butyl 2-(3-chloropyrazin- (1H)-ylidene)-2-cyanoacetateappears as NH-acid.

In the molecule of the title compound (Fig. 1) the bond lengths and angles characterizing the geometry of the pyrazines skeleton are typical for this group compounds (Vishweshwar et al. 2000; Wardell et al. 2006). The compound is essentially planar except for the n-butoxy group (r.m.s. deviation from the least-squares plane - 0.0131 (1) Å for 11 non-H atoms. An intramolecular N2—H2B···O1 contact generates a S(6) ring motif which stabilizes the molecular conformation. The n-butoxy chain in the molecule is disordered over two sets of sites in a 0.50 (1):0.50 (1) ratio.

Related literature top

For applications of this class of compounds, see: Matter et al. (2005); Kaliszan et al. (1985); Petrusewicz et al. (1992, 1993, 1995). For pyrazinyl–pyrazylidene tautomerism, see: Pilarski et al. (1984). For related structures, see: Vishweshwar et al. (2000); Wardell et al. (2006). For the synthesis, see: Pilarski & Foks (1981, 1982).

Experimental top

2-butyl 2-(3-chloropyrazin-2(1H)-ylidene)-2-cyanoacetate was obtained bygeneral method described in papers (Pilarski et al., 1981; Pilarski et al., 1982). Crystallization of this compound from methanol forms a crystal.

Computing details top

Data collection: CrysAlis CCD (Oxford Diffraction, 2006); cell refinement: CrysAlis RED (Oxford Diffraction, 2006); data reduction: CrysAlis RED (Oxford Diffraction, 2006); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997); software used to prepare material for publication: WinGX (Farrugia, 1999).

Figures top

Fig. 1. The moleculare structure of the title compound showing the atomic numbering scheme. Displacement ellipsoids are drawn at the 50% probability level.

n-Butyl 2-(3-chloro-1,2-dihydropyrazin-2-ylidene)-2-cyanoacetate top

Crystal data top

C₁₁H₁₂ClN₃O₂	F(000) = 528
M_r = 253.69	D_x = 1.27 Mg m⁻³
Monoclinic, Cc	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: C -2yc	Cell parameters from 1500 reflections
a = 4.918 (3) Å	θ = 2.5–32.3°
b = 25.642 (7) Å	µ = 0.28 mm⁻¹
c = 10.573 (4) Å	T = 120 K
β = 95.80 (3)°	Block, yellow
V = 1326.7 (9) Å³	0.57 × 0.11 × 0.07 mm
Z = 4

Data collection top

Oxford Diffraction KM-4/Xcalibur diffractometer with a Sapphire2 (large Be window) detector	1687 independent reflections
Graphite monochromator	1219 reflections with I > 2σ(I)
Detector resolution: 8.1883 pixels mm^-1	R_int = 0.034
0.75° wide ω scans	θ_max = 25.5°, θ_min = 2.5°
Absorption correction: gaussian (CrysAlis PRO; Oxford Diffraction, 2007)	h = −3→5
T_min = 0.923, T_max = 0.987	k = −31→31
4629 measured reflections	l = −12→12

Refinement top

Refinement on F²	Secondary atom site location: difference Fourier map
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.047	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.156	w = 1/[σ²(F_o²) + (0.1833P)²] where P = (F_o² + 2F_c²)/3
S = 1.04	(Δ/σ)_max < 0.001
1687 reflections	Δρ_max = 0.24 e Å⁻³
154 parameters	Δρ_min = −0.23 e Å⁻³
1 restraint	Absolute structure: Flack (1983), 466 Friedel pairs
Primary atom site location: structure-invariant direct methods	Absolute structure parameter: 0.05 (18)

Crystal data top

C₁₁H₁₂ClN₃O₂	V = 1326.7 (9) Å³
M_r = 253.69	Z = 4
Monoclinic, Cc	Mo Kα radiation
a = 4.918 (3) Å	µ = 0.28 mm⁻¹
b = 25.642 (7) Å	T = 120 K
c = 10.573 (4) Å	0.57 × 0.11 × 0.07 mm
β = 95.80 (3)°

Data collection top

Oxford Diffraction KM-4/Xcalibur diffractometer with a Sapphire2 (large Be window) detector	1687 independent reflections
Absorption correction: gaussian (CrysAlis PRO; Oxford Diffraction, 2007)	1219 reflections with I > 2σ(I)
T_min = 0.923, T_max = 0.987	R_int = 0.034
4629 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.047	H atoms treated by a mixture of independent and constrained refinement
wR(F²) = 0.156	Δρ_max = 0.24 e Å⁻³
S = 1.04	Δρ_min = −0.23 e Å⁻³
1687 reflections	Absolute structure: Flack (1983), 466 Friedel pairs
154 parameters	Absolute structure parameter: 0.05 (18)
1 restraint

Special details top

Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s involving l.s. planes.

Refinement. Refinement of F² against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F², conventional R-factors R are based on F, with F set to zero for negative F². The threshold expression of F² > σ(F²) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F² are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq	Occ. (<1)
Cl1	0.7083 (3)	0.42260 (5)	0.30244 (15)	0.0753 (4)
O1	0.0928 (8)	0.54438 (16)	0.6099 (3)	0.0731 (12)
N1	0.4291 (11)	0.36488 (18)	0.4525 (5)	0.0827 (13)
N2	0.1819 (9)	0.4445 (2)	0.5738 (4)	0.0612 (12)
N3	0.7225 (16)	0.55178 (17)	0.2917 (6)	0.0874 (12)
C1	0.2496 (17)	0.3549 (3)	0.5468 (7)	0.0905 (19)
H1A	0.2102	0.3199	0.5681	0.109*
C2	0.1303 (11)	0.3956 (3)	0.6086 (5)	0.0695 (16)
H2A	0.0153	0.3889	0.6737	0.083*
C3	0.3572 (10)	0.4596 (2)	0.4816 (4)	0.0548 (12)
C4	0.4796 (11)	0.4144 (2)	0.4225 (4)	0.0649 (13)
C5	0.4002 (10)	0.5136 (2)	0.4565 (4)	0.0569 (10)
C6	0.5828 (11)	0.5330 (2)	0.3632 (5)	0.0617 (11)
C7	0.2549 (12)	0.5528 (2)	0.5259 (5)	0.0626 (15)
O2	0.3471 (16)	0.6051 (3)	0.5012 (7)	0.050 (2)*	0.5
C8	0.202 (2)	0.6474 (4)	0.5635 (11)	0.056 (3)*	0.5
H8A	0.2504	0.647	0.6566	0.067*	0.5
H8B	0.0014	0.6434	0.5458	0.067*	0.5
C9	0.296 (2)	0.6977 (4)	0.5064 (9)	0.070 (3)*	0.5
H9A	0.4939	0.7017	0.5331	0.084*	0.5
H9B	0.2014	0.7269	0.5444	0.084*	0.5
C10	0.253 (3)	0.7037 (4)	0.3607 (9)	0.072 (3)*	0.5
H10A	0.3655	0.6769	0.3231	0.086*	0.5
H10B	0.0594	0.6955	0.3331	0.086*	0.5
C11	0.316 (3)	0.7546 (5)	0.3052 (16)	0.095 (4)*	0.5
H11A	0.1591	0.7664	0.248	0.143*	0.5
H11B	0.4758	0.751	0.2573	0.143*	0.5
H11C	0.3558	0.7802	0.3734	0.143*	0.5
O2A	0.268 (2)	0.6013 (4)	0.4705 (9)	0.071 (3)*	0.5
C8A	0.111 (3)	0.6434 (5)	0.5272 (13)	0.080 (4)*	0.5
H8AA	0.1828	0.6493	0.6169	0.095*	0.5
H8AB	−0.0843	0.6336	0.5246	0.095*	0.5
C9A	0.142 (3)	0.6924 (5)	0.4496 (14)	0.102 (4)*	0.5
H9A1	0.0102	0.6892	0.3728	0.122*	0.5
H9A2	0.0775	0.7217	0.4998	0.122*	0.5
C10A	0.402 (3)	0.7092 (5)	0.4057 (13)	0.092 (3)*	0.5
H10C	0.4668	0.6798	0.3559	0.11*	0.5
H10D	0.5335	0.7124	0.4827	0.11*	0.5
C11A	0.433 (4)	0.7571 (5)	0.3292 (13)	0.089 (4)*	0.5
H11D	0.6227	0.7691	0.3421	0.133*	0.5
H11E	0.3116	0.7843	0.3561	0.133*	0.5
H11F	0.3845	0.7493	0.239	0.133*	0.5
H2B	0.150 (14)	0.4691 (19)	0.627 (5)	0.10 (2)*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.0730 (7)	0.0881 (7)	0.0692 (6)	0.0104 (9)	0.0279 (5)	−0.0026 (8)
O1	0.085 (3)	0.067 (2)	0.073 (2)	0.003 (2)	0.035 (2)	0.0011 (18)
N1	0.098 (3)	0.070 (3)	0.085 (3)	0.007 (2)	0.036 (2)	0.001 (2)
N2	0.063 (3)	0.067 (3)	0.055 (2)	0.006 (2)	0.013 (2)	−0.003 (2)
N3	0.087 (3)	0.098 (3)	0.082 (3)	−0.002 (3)	0.034 (2)	0.021 (3)
C1	0.119 (5)	0.063 (3)	0.097 (4)	0.004 (3)	0.049 (4)	−0.001 (3)
C2	0.075 (4)	0.071 (4)	0.067 (3)	−0.004 (3)	0.028 (3)	0.002 (3)
C3	0.049 (3)	0.073 (3)	0.042 (2)	0.003 (2)	0.0044 (19)	−0.007 (2)
C4	0.063 (3)	0.080 (4)	0.053 (2)	0.009 (2)	0.014 (2)	−0.002 (2)
C5	0.055 (2)	0.065 (3)	0.052 (2)	−0.002 (2)	0.0109 (18)	0.0014 (17)
C6	0.058 (2)	0.073 (3)	0.056 (2)	0.002 (2)	0.014 (2)	0.002 (2)
C7	0.069 (3)	0.060 (4)	0.062 (3)	−0.007 (3)	0.018 (3)	0.004 (3)

Geometric parameters (Å, º) top

Cl1—C4	1.791 (5)	C9—H9A	0.99
O1—C7	1.271 (7)	C9—H9B	0.99
N1—C4	1.338 (7)	C10—C11	1.478 (14)
N1—C1	1.421 (8)	C10—H10A	0.99
N2—C2	1.338 (9)	C10—H10B	0.99
N2—C3	1.419 (8)	C11—H11A	0.98
N2—H2B	0.87 (2)	C11—H11B	0.98
N3—C6	1.175 (8)	C11—H11C	0.98
C1—C2	1.392 (10)	O2A—C8A	1.489 (17)
C1—H1A	0.95	C8A—C9A	1.516 (14)
C2—H2A	0.95	C8A—H8AA	0.99
C3—C5	1.428 (7)	C8A—H8AB	0.99
C3—C4	1.475 (7)	C9A—C10A	1.469 (14)
C5—C7	1.472 (8)	C9A—H9A1	0.99
C5—C6	1.486 (7)	C9A—H9A2	0.99
C7—O2A	1.379 (11)	C10A—C11A	1.487 (14)
C7—O2	1.448 (10)	C10A—H10C	0.99
O2—C8	1.489 (13)	C10A—H10D	0.99
C8—C9	1.514 (12)	C11A—H11D	0.98
C8—H8A	0.99	C11A—H11E	0.98
C8—H8B	0.99	C11A—H11F	0.98
C9—C10	1.541 (12)

C4—N1—C1	118.8 (5)	C10—C9—H9A	107.8
C2—N2—C3	126.2 (5)	C8—C9—H9B	107.8
C2—N2—H2B	117 (5)	C10—C9—H9B	107.8
C3—N2—H2B	114 (5)	H9A—C9—H9B	107.2
C2—C1—N1	121.0 (6)	C11—C10—C9	118.2 (10)
C2—C1—H1A	119.5	C11—C10—H10A	107.8
N1—C1—H1A	119.5	C9—C10—H10A	107.8
N2—C2—C1	118.3 (5)	C11—C10—H10B	107.8
N2—C2—H2A	120.9	C9—C10—H10B	107.8
C1—C2—H2A	120.9	H10A—C10—H10B	107.1
N2—C3—C5	120.3 (5)	C7—O2A—C8A	115.7 (8)
N2—C3—C4	112.3 (5)	O2A—C8A—C9A	107.3 (11)
C5—C3—C4	127.5 (5)	O2A—C8A—H8AA	110.2
N1—C4—C3	123.5 (4)	C9A—C8A—H8AA	110.2
N1—C4—Cl1	115.1 (4)	O2A—C8A—H8AB	110.2
C3—C4—Cl1	121.4 (4)	C9A—C8A—H8AB	110.2
C3—C5—C7	118.7 (4)	H8AA—C8A—H8AB	108.5
C3—C5—C6	124.0 (4)	C10A—C9A—C8A	123.5 (13)
C7—C5—C6	117.3 (5)	C10A—C9A—H9A1	106.5
N3—C6—C5	175.5 (5)	C8A—C9A—H9A1	106.5
O1—C7—O2A	120.7 (6)	C10A—C9A—H9A2	106.5
O1—C7—O2	120.9 (5)	C8A—C9A—H9A2	106.5
O2A—C7—O2	19.8 (5)	H9A1—C9A—H9A2	106.5
O1—C7—C5	127.1 (5)	C9A—C10A—C11A	123.6 (13)
O2A—C7—C5	111.0 (6)	C9A—C10A—H10C	106.4
O2—C7—C5	111.5 (5)	C11A—C10A—H10C	106.4
C7—O2—C8	115.0 (7)	C9A—C10A—H10D	106.4
O2—C8—C9	105.3 (8)	C11A—C10A—H10D	106.4
O2—C8—H8A	110.7	H10C—C10A—H10D	106.5
C9—C8—H8A	110.7	C10A—C11A—H11D	109.5
O2—C8—H8B	110.7	C10A—C11A—H11E	109.5
C9—C8—H8B	110.7	H11D—C11A—H11E	109.5
H8A—C8—H8B	108.8	C10A—C11A—H11F	109.5
C8—C9—C10	117.8 (9)	H11D—C11A—H11F	109.5
C8—C9—H9A	107.8	H11E—C11A—H11F	109.5

C4—N1—C1—C2	−0.9 (10)	C6—C5—C7—O1	−179.2 (5)
C3—N2—C2—C1	−2.4 (9)	C3—C5—C7—O2A	−166.0 (6)
N1—C1—C2—N2	2.2 (11)	C6—C5—C7—O2A	13.6 (8)
C2—N2—C3—C5	−178.1 (5)	C3—C5—C7—O2	172.8 (5)
C2—N2—C3—C4	1.2 (7)	C6—C5—C7—O2	−7.6 (8)
C1—N1—C4—C3	−0.4 (8)	O1—C7—O2—C8	−10.3 (11)
C1—N1—C4—Cl1	−179.9 (5)	O2A—C7—O2—C8	85.0 (19)
N2—C3—C4—N1	0.3 (7)	C5—C7—O2—C8	177.5 (7)
C5—C3—C4—N1	179.5 (5)	C7—O2—C8—C9	−170.4 (8)
N2—C3—C4—Cl1	179.8 (3)	O2—C8—C9—C10	56.8 (12)
C5—C3—C4—Cl1	−1.0 (7)	C8—C9—C10—C11	173.4 (12)
N2—C3—C5—C7	−1.4 (6)	O1—C7—O2A—C8A	7.6 (13)
C4—C3—C5—C7	179.5 (5)	O2—C7—O2A—C8A	−89.0 (19)
N2—C3—C5—C6	179.1 (5)	C5—C7—O2A—C8A	175.8 (9)
C4—C3—C5—C6	−0.1 (8)	C7—O2A—C8A—C9A	−177.5 (10)
C3—C5—C6—N3	18E1 (10)	O2A—C8A—C9A—C10A	−42.8 (19)
C7—C5—C6—N3	0 (8)	C8A—C9A—C10A—C11A	179.8 (14)
C3—C5—C7—O1	1.2 (8)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2B···O1	0.87 (2)	1.96 (5)	2.632 (6)	133 (6)

Experimental details

Crystal data
Chemical formula	C₁₁H₁₂ClN₃O₂
M_r	253.69
Crystal system, space group	Monoclinic, Cc
Temperature (K)	120
a, b, c (Å)	4.918 (3), 25.642 (7), 10.573 (4)
β (°)	95.80 (3)
V (Å³)	1326.7 (9)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.28
Crystal size (mm)	0.57 × 0.11 × 0.07

Data collection
Diffractometer	Oxford Diffraction KM-4/Xcalibur diffractometer with a Sapphire2 (large Be window) detector
Absorption correction	Gaussian (CrysAlis PRO; Oxford Diffraction, 2007)
T_min, T_max	0.923, 0.987
No. of measured, independent and observed [I > 2σ(I)] reflections	4629, 1687, 1219
R_int	0.034
(sin θ/λ)_max (Å⁻¹)	0.606

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.047, 0.156, 1.04
No. of reflections	1687
No. of parameters	154
No. of restraints	1
H-atom treatment	H atoms treated by a mixture of independent and constrained refinement
Δρ_max, Δρ_min (e Å⁻³)	0.24, −0.23
Absolute structure	Flack (1983), 466 Friedel pairs
Absolute structure parameter	0.05 (18)

Computer programs: CrysAlis CCD (Oxford Diffraction, 2006), CrysAlis RED (Oxford Diffraction, 2006), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 for Windows (Farrugia, 1997), WinGX (Farrugia, 1999).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2B···O1	0.87 (2)	1.96 (5)	2.632 (6)	133 (6)

Acknowledgements

The authors thank Drs Katarzyna Baranowska and Antoni Konitz for helpful discussions during the preparation of the manuscript. The work has been supported by the Fund for Science in the Year 2009 as a research project (DS/8410–4-0139–9).

References

Farrugia, L. J. (1997). J. Appl. Cryst. 30, 565. CrossRef IUCr Journals Google Scholar
Farrugia, L. J. (1999). J. Appl. Cryst. 32, 837–838. CrossRef CAS IUCr Journals Google Scholar
Flack, H. D. (1983). Acta Cryst. A39, 876–881. CrossRef CAS Web of Science IUCr Journals Google Scholar
Kaliszan, R., Pilarski, B., Osmialowski, K., Strzalkowska-Grad, H. & Hrac, E. (1985). Pharm. Weekbl. [Sci], 7, 141–145. CrossRef CAS PubMed Web of Science Google Scholar
Matter, H., Kumar, H. S. A., Fedorov, R., Frey, A., Kotsonis, P., Hartmann, E., Frohlich, L. G., Reif, A., Pfleiderer, W., Scheurer, P., Ghosh, D. K., Schlichting, I. & Schmidt, H. H. W. (2005). J. Med. Chem. 48, 4783–4792. Web of Science CrossRef PubMed CAS Google Scholar
Oxford Diffraction (2006). CrysAlis CCD and CrysAlis RED. Oxford Diffraction Ltd, Abingdon, England. Google Scholar
Oxford Diffraction (2007). CrysAlis Pro. Oxford Diffraction Ltd, Yarnton, England. Google Scholar
Petrusewicz, J., Gami-Yilinkou, R., Kaliszan, R., Pilarski, B. & Foks, H. (1993). Gen. Pharmacol. 24, 17–22. CrossRef CAS PubMed Web of Science Google Scholar
Petrusewicz, J., Gami-Yilinkou, R., Pilarski, B. & Kaliszan, R. (1992). Pharmacol. Tonic. 70, 448–452. CrossRef CAS Google Scholar
Petrusewicz, J., Turowski, M., Foks, H., Pilarski, B. & Kaliszan, R. (1995). Life Sci. 56, 667–677. CrossRef CAS PubMed Web of Science Google Scholar
Pilarski, B. & Foks, H. (1981). Polish Patent No. P-232409. Google Scholar
Pilarski, B. & Foks, H. (1982). Polish Patent No. P-234716. Google Scholar
Pilarski, B., Foks, H., Osmialowski, K. & Kaliszan, R. (1984). Monatsh. Chem. 115, 179–185. CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
Vishweshwar, P., Nangia, A. & Lynch, V. M. (2000). Acta Cryst. C56, 1512–1514. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Wardell, S. M. S. V., de Souza, M. V. N., Wardell, J. L., Low, J. N. & Glidewell, C. (2006). Acta Cryst. E62, o3765–o3767. Web of Science CSD CrossRef IUCr Journals Google Scholar