organic compounds
2′-(3-Hydroxybenzylidene)pyrazine-2-carbohydrazide monohydrate
aDepartment of Chemistry, Tianjin University, Tianjin 300072, People's Republic of China
*Correspondence e-mail: tjuhelei@yahoo.com.cn
The title compound, C12H10N4O2·H2O, was synthesized by the reaction of pyrazine-2-carboxylic acid hydrazide and 3-hydroxybenzaldehyde in ethanol. In the the organic molecules are linked into extended chains by intermolecular N(amide)—H⋯O(hydroxy) hydrogen bonds. Additional hydrogen bonds between the water molecule and three adjacent organic molecules, as well as face-to-face π–π stacking interactions between the benzene and pyrazine rings [centroid-to-centroid separation = 3.669 (2) Å and offset = 1.362 Å], link the molecules into a three-dimensional framework.
Related literature
For pharmacological and photochromic properties of hydrazonecarbonyl compounds, see: Parashar et al. (1988); Hadjoudis et al. (1987). For related pyrazinecarboxylic acid see: Gardner et al. (1956);
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 1997); cell SMART; data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S1600536807062708/ln2011sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536807062708/ln2011Isup2.hkl
Compound (I) was synthesized by the reaction of pyrazine-2-carboxylic acid hydrazide (0.01 mol, 1.38 g) and 3-hydroxybenzaldehyde (0.01 mol, 1.52 g) in ethanol. The solution was refluxed for 3 h. After cooling down, the solid product was filtered and recrystallized from ethanol with a yield of 75%, m.p. 540–541 K. Crystals suitable for single-crystal X-ray diffraction were grown by slow evaporation of a mixture of methanol and water (5: 1).
All H atoms were initially located in a difference Fourier map. The carbon bound H atoms were then constrained to an ideal geometry, with C(phenyl)—H distances of 0.93 Å and Uiso(H) = 1.2Ueq(C). The H atoms attached to the hydroxy and water O atoms and to the N atom were refined freely with Uiso(H) = 1.5Ueq(O) and 1.2Ueq(N), respectively.
Hydrazonecarbonyl compounds have received considerable attention due to their pharmacological activities (Parashar et al., 1988) and photochromic properties (Hadjoudis et al., 1987). A series of similar pyrazinylcarboxylic acid
has been reported previously (Gardner et al., 1956). As a continuation of the work of our group, we report here the of 2'-(3-hydroxybenzylidene)pyrazine-2-carbohydrazide monohydrate, (I).The
contains one organic molecule and one molecule of H2O. The carbohydrazide molecule deviates only slightly from planarity with a dihedral angle of 11.60 (3)° between the planes of the pyrazinyl and phenyl rings (Fig. 1).In the crystal, the organic molecules of (I) are arranged in slightly tilted rows. Within the rows, amide atom N3 acts as a hydrogen bond donor to the atom O2 of the hydroxy group in a neighbouring molecule, thereby forming extended chains, which run parallel to the a axis (Table 1, Fig. 2).
The water O atom acts as a hydrogen bond acceptor from the hydroxy group of an organic molecule. One water H atom forms a hydrogen bond with the N atom in the pyrazinyl ring of another adjacent molecule, while the other H atom forms bifurcated hydrogen bonds with the carbonyl O atom, O1, and the N4 atom from another molecule of I, thereby forming a five-membered hydrogen bond ring (Fig. 3).
The crystal packing is characterized by π···π stacking interactions. The molecules are stacked in an antiparalled fashion, with a pyrazinyl to phenyl ring centroid-centroid separation of 3.669 (2) Å and an offset of 1.362 Å. Together with the hydrogen bonds, these interactions lead to a three-dimensional supramolecular network pattern (Fig. 3).
For pharmacological and photochromic properties of hydrazonecarbonyl compounds, see: Parashar et al. (1988); Hadjoudis et al. (1987). For related pyrazinylcarboxylic acid
see: Gardner et al. (1956)Data collection: SMART (Bruker, 1997); cell
SMART (Bruker, 1997); data reduction: SAINT (Bruker, 1997); program(s) used to solve structure: SHELXS97 (Sheldrick, 1997); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Bruker, 1997); software used to prepare material for publication: SHELXTL (Bruker, 1997).Fig. 1. The structure of (I), showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 30% probability level. | |
Fig. 2. View along the c axis showing a one-dimensional chain of the organic molecule. The water molecules have been omitted for clarity. Dashed lines represent the hydrogen bonds. Symmetry code: (A) x, y - 1, z. | |
Fig. 3. The crystal packing viewed down the a axis showing the three-dimensional structure formed by hydrogen bonds (dashed lines) and π···π stacking interactions. |
C12H10N4O2·H2O | Z = 2 |
Mr = 260.26 | F(000) = 272 |
Triclinic, P1 | Dx = 1.458 Mg m−3 |
a = 8.062 (3) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 8.186 (3) Å | Cell parameters from 658 reflections |
c = 9.449 (3) Å | θ = 2.2–23.0° |
α = 95.122 (6)° | µ = 0.11 mm−1 |
β = 103.169 (6)° | T = 294 K |
γ = 99.827 (7)° | Block, colourless |
V = 592.9 (4) Å3 | 0.24 × 0.22 × 0.18 mm |
Bruker CCD area-detector diffractometer | 2083 independent reflections |
Radiation source: fine-focus sealed tube | 1112 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.024 |
φ and ω scans | θmax = 25.0°, θmin = 2.2° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −9→9 |
Tmin = 0.962, Tmax = 0.981 | k = −9→4 |
3017 measured reflections | l = −10→11 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.051 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.140 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.02 | w = 1/[σ2(Fo2) + (0.0631P)2] where P = (Fo2 + 2Fc2)/3 |
2083 reflections | (Δ/σ)max < 0.001 |
184 parameters | Δρmax = 0.20 e Å−3 |
0 restraints | Δρmin = −0.23 e Å−3 |
C12H10N4O2·H2O | γ = 99.827 (7)° |
Mr = 260.26 | V = 592.9 (4) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.062 (3) Å | Mo Kα radiation |
b = 8.186 (3) Å | µ = 0.11 mm−1 |
c = 9.449 (3) Å | T = 294 K |
α = 95.122 (6)° | 0.24 × 0.22 × 0.18 mm |
β = 103.169 (6)° |
Bruker CCD area-detector diffractometer | 2083 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1112 reflections with I > 2σ(I) |
Tmin = 0.962, Tmax = 0.981 | Rint = 0.024 |
3017 measured reflections |
R[F2 > 2σ(F2)] = 0.051 | 0 restraints |
wR(F2) = 0.140 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.02 | Δρmax = 0.20 e Å−3 |
2083 reflections | Δρmin = −0.23 e Å−3 |
184 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
O1 | 0.4727 (3) | 0.5725 (3) | 0.7739 (2) | 0.0587 (7) | |
O2 | 0.0678 (3) | 1.0884 (3) | 0.3575 (3) | 0.0567 (7) | |
H2 | −0.014 (5) | 1.134 (5) | 0.314 (4) | 0.085* | |
N1 | 0.4525 (3) | 0.1480 (3) | 0.6449 (2) | 0.0392 (7) | |
N2 | 0.6326 (3) | 0.1543 (3) | 0.9355 (3) | 0.0472 (7) | |
N3 | 0.3179 (4) | 0.4148 (3) | 0.5600 (3) | 0.0397 (7) | |
H3 | 0.299 (4) | 0.322 (4) | 0.513 (3) | 0.048* | |
N4 | 0.2524 (3) | 0.5480 (3) | 0.5068 (3) | 0.0402 (7) | |
C1 | 0.5113 (4) | 0.0166 (4) | 0.6931 (3) | 0.0448 (9) | |
H1 | 0.4921 | −0.0808 | 0.6281 | 0.054* | |
C2 | 0.6005 (4) | 0.0195 (4) | 0.8370 (3) | 0.0465 (9) | |
H2A | 0.6393 | −0.0760 | 0.8658 | 0.056* | |
C3 | 0.5740 (4) | 0.2865 (4) | 0.8871 (3) | 0.0444 (8) | |
H3A | 0.5930 | 0.3836 | 0.9525 | 0.053* | |
C4 | 0.4858 (4) | 0.2849 (4) | 0.7429 (3) | 0.0337 (7) | |
C5 | 0.4252 (4) | 0.4375 (4) | 0.6954 (3) | 0.0398 (8) | |
C6 | 0.1605 (4) | 0.5199 (4) | 0.3753 (3) | 0.0388 (8) | |
H6 | 0.1440 | 0.4139 | 0.3235 | 0.047* | |
C7 | 0.0801 (4) | 0.6459 (4) | 0.3024 (3) | 0.0355 (8) | |
C8 | −0.0298 (4) | 0.5994 (4) | 0.1629 (3) | 0.0434 (9) | |
H8 | −0.0512 | 0.4892 | 0.1188 | 0.052* | |
C9 | −0.1069 (4) | 0.7147 (4) | 0.0899 (3) | 0.0501 (9) | |
H9 | −0.1803 | 0.6823 | −0.0034 | 0.060* | |
C10 | −0.0764 (4) | 0.8785 (4) | 0.1537 (3) | 0.0450 (9) | |
H10 | −0.1286 | 0.9565 | 0.1035 | 0.054* | |
C11 | 0.0317 (4) | 0.9261 (4) | 0.2922 (3) | 0.0378 (8) | |
C12 | 0.1093 (4) | 0.8114 (4) | 0.3664 (3) | 0.0385 (8) | |
H12 | 0.1818 | 0.8444 | 0.4600 | 0.046* | |
O3 | 0.1948 (3) | 0.7733 (3) | 0.7579 (2) | 0.0590 (7) | |
H3B | 0.242 (5) | 0.816 (4) | 0.847 (3) | 0.088* | |
H3C | 0.246 (5) | 0.708 (4) | 0.708 (4) | 0.088* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0769 (18) | 0.0433 (15) | 0.0455 (14) | 0.0237 (13) | −0.0117 (13) | −0.0016 (12) |
O2 | 0.0651 (17) | 0.0367 (14) | 0.0564 (15) | 0.0197 (12) | −0.0147 (12) | 0.0016 (11) |
N1 | 0.0441 (16) | 0.0446 (17) | 0.0289 (14) | 0.0186 (14) | 0.0008 (12) | 0.0061 (13) |
N2 | 0.0529 (18) | 0.0528 (19) | 0.0355 (16) | 0.0205 (15) | −0.0003 (13) | 0.0138 (14) |
N3 | 0.0492 (17) | 0.0342 (16) | 0.0355 (16) | 0.0202 (15) | 0.0004 (13) | 0.0076 (12) |
N4 | 0.0455 (16) | 0.0401 (16) | 0.0378 (16) | 0.0203 (14) | 0.0037 (13) | 0.0139 (13) |
C1 | 0.055 (2) | 0.044 (2) | 0.0365 (19) | 0.0190 (18) | 0.0060 (16) | 0.0072 (16) |
C2 | 0.055 (2) | 0.048 (2) | 0.040 (2) | 0.0218 (19) | 0.0064 (17) | 0.0158 (17) |
C3 | 0.051 (2) | 0.045 (2) | 0.0348 (19) | 0.0150 (17) | 0.0024 (16) | 0.0059 (16) |
C4 | 0.0332 (17) | 0.0430 (19) | 0.0275 (17) | 0.0159 (15) | 0.0051 (14) | 0.0083 (15) |
C5 | 0.0407 (19) | 0.046 (2) | 0.0343 (19) | 0.0171 (17) | 0.0045 (16) | 0.0085 (17) |
C6 | 0.047 (2) | 0.0365 (19) | 0.0335 (19) | 0.0132 (16) | 0.0068 (16) | 0.0080 (14) |
C7 | 0.0358 (18) | 0.0397 (19) | 0.0338 (18) | 0.0164 (16) | 0.0049 (15) | 0.0120 (15) |
C8 | 0.056 (2) | 0.0376 (19) | 0.0332 (19) | 0.0139 (17) | 0.0012 (16) | 0.0039 (15) |
C9 | 0.063 (2) | 0.051 (2) | 0.0303 (18) | 0.0224 (19) | −0.0075 (16) | 0.0037 (16) |
C10 | 0.051 (2) | 0.047 (2) | 0.0360 (19) | 0.0238 (18) | −0.0039 (16) | 0.0116 (16) |
C11 | 0.0393 (19) | 0.0331 (19) | 0.0390 (19) | 0.0111 (16) | 0.0025 (15) | 0.0059 (15) |
C12 | 0.0388 (19) | 0.042 (2) | 0.0324 (18) | 0.0129 (16) | −0.0016 (15) | 0.0079 (15) |
O3 | 0.0716 (18) | 0.0561 (17) | 0.0466 (15) | 0.0334 (14) | −0.0036 (13) | 0.0000 (13) |
O1—C5 | 1.224 (4) | C4—C5 | 1.486 (4) |
O2—C11 | 1.368 (4) | C6—C7 | 1.453 (4) |
O2—H2 | 0.86 (4) | C6—H6 | 0.9300 |
N1—C1 | 1.324 (4) | C7—C8 | 1.390 (4) |
N1—C4 | 1.336 (3) | C7—C12 | 1.391 (4) |
N2—C2 | 1.327 (4) | C8—C9 | 1.369 (4) |
N2—C3 | 1.330 (4) | C8—H8 | 0.9300 |
N3—C5 | 1.348 (4) | C9—C10 | 1.377 (4) |
N3—N4 | 1.376 (3) | C9—H9 | 0.9300 |
N3—H3 | 0.82 (3) | C10—C11 | 1.377 (4) |
N4—C6 | 1.272 (3) | C10—H10 | 0.9300 |
C1—C2 | 1.382 (4) | C11—C12 | 1.373 (4) |
C1—H1 | 0.9300 | C12—H12 | 0.9300 |
C2—H2A | 0.9300 | O3—H3B | 0.86 (2) |
C3—C4 | 1.384 (4) | O3—H3C | 0.89 (2) |
C3—H3A | 0.9300 | ||
C11—O2—H2 | 106 (3) | N4—C6—C7 | 122.9 (3) |
C1—N1—C4 | 116.3 (3) | N4—C6—H6 | 118.5 |
C2—N2—C3 | 115.9 (3) | C7—C6—H6 | 118.5 |
C5—N3—N4 | 119.2 (3) | C8—C7—C12 | 118.7 (3) |
C5—N3—H3 | 117 (2) | C8—C7—C6 | 118.7 (3) |
N4—N3—H3 | 124 (2) | C12—C7—C6 | 122.6 (3) |
C6—N4—N3 | 115.7 (3) | C9—C8—C7 | 120.5 (3) |
N1—C1—C2 | 122.1 (3) | C9—C8—H8 | 119.8 |
N1—C1—H1 | 118.9 | C7—C8—H8 | 119.8 |
C2—C1—H1 | 118.9 | C8—C9—C10 | 120.4 (3) |
N2—C2—C1 | 122.1 (3) | C8—C9—H9 | 119.8 |
N2—C2—H2A | 119.0 | C10—C9—H9 | 119.8 |
C1—C2—H2A | 119.0 | C9—C10—C11 | 119.7 (3) |
N2—C3—C4 | 122.4 (3) | C9—C10—H10 | 120.1 |
N2—C3—H3A | 118.8 | C11—C10—H10 | 120.1 |
C4—C3—H3A | 118.8 | O2—C11—C12 | 118.5 (3) |
N1—C4—C3 | 121.3 (3) | O2—C11—C10 | 121.2 (3) |
N1—C4—C5 | 119.0 (3) | C12—C11—C10 | 120.3 (3) |
C3—C4—C5 | 119.7 (3) | C11—C12—C7 | 120.4 (3) |
O1—C5—N3 | 123.6 (3) | C11—C12—H12 | 119.8 |
O1—C5—C4 | 121.7 (3) | C7—C12—H12 | 119.8 |
N3—C5—C4 | 114.7 (3) | H3B—O3—H3C | 122 (4) |
C5—N3—N4—C6 | 176.0 (3) | C3—C4—C5—N3 | −170.0 (3) |
C4—N1—C1—C2 | 0.8 (4) | N3—N4—C6—C7 | 179.4 (3) |
C3—N2—C2—C1 | −0.2 (5) | N4—C6—C7—C8 | −174.7 (3) |
N1—C1—C2—N2 | 0.0 (5) | N4—C6—C7—C12 | 5.6 (5) |
C2—N2—C3—C4 | −0.3 (5) | C12—C7—C8—C9 | 0.3 (4) |
C1—N1—C4—C3 | −1.3 (4) | C6—C7—C8—C9 | −179.4 (3) |
C1—N1—C4—C5 | 179.2 (3) | C7—C8—C9—C10 | 0.0 (5) |
N2—C3—C4—N1 | 1.1 (5) | C8—C9—C10—C11 | −0.3 (5) |
N2—C3—C4—C5 | −179.4 (3) | C9—C10—C11—O2 | 178.6 (3) |
N4—N3—C5—O1 | −2.0 (5) | C9—C10—C11—C12 | 0.2 (5) |
N4—N3—C5—C4 | 179.0 (3) | O2—C11—C12—C7 | −178.2 (3) |
N1—C4—C5—O1 | −169.5 (3) | C10—C11—C12—C7 | 0.2 (5) |
C3—C4—C5—O1 | 11.0 (5) | C8—C7—C12—C11 | −0.5 (4) |
N1—C4—C5—N3 | 9.5 (4) | C6—C7—C12—C11 | 179.2 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O3i | 0.86 (4) | 1.78 (4) | 2.634 (3) | 174 (4) |
N3—H3···N1 | 0.82 (3) | 2.31 (3) | 2.705 (3) | 110 (3) |
N3—H3···O2ii | 0.82 (3) | 2.51 (3) | 3.218 (4) | 145 (3) |
O3—H3B···N2iii | 0.86 (2) | 2.04 (3) | 2.873 (3) | 163 (4) |
O3—H3C···N4 | 0.89 (2) | 2.22 (3) | 3.043 (3) | 152 (3) |
O3—H3C···O1 | 0.89 (2) | 2.29 (3) | 2.982 (3) | 134 (3) |
Symmetry codes: (i) −x, −y+2, −z+1; (ii) x, y−1, z; (iii) −x+1, −y+1, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C12H10N4O2·H2O |
Mr | 260.26 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 294 |
a, b, c (Å) | 8.062 (3), 8.186 (3), 9.449 (3) |
α, β, γ (°) | 95.122 (6), 103.169 (6), 99.827 (7) |
V (Å3) | 592.9 (4) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.11 |
Crystal size (mm) | 0.24 × 0.22 × 0.18 |
Data collection | |
Diffractometer | Bruker CCD area-detector |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.962, 0.981 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3017, 2083, 1112 |
Rint | 0.024 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.051, 0.140, 1.02 |
No. of reflections | 2083 |
No. of parameters | 184 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.20, −0.23 |
Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1997), SHELXS97 (Sheldrick, 1997), SHELXL97 (Sheldrick, 1997), SHELXTL (Bruker, 1997).
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O3i | 0.86 (4) | 1.78 (4) | 2.634 (3) | 174 (4) |
N3—H3···N1 | 0.82 (3) | 2.31 (3) | 2.705 (3) | 110 (3) |
N3—H3···O2ii | 0.82 (3) | 2.51 (3) | 3.218 (4) | 145 (3) |
O3—H3B···N2iii | 0.86 (2) | 2.04 (3) | 2.873 (3) | 163 (4) |
O3—H3C···N4 | 0.89 (2) | 2.22 (3) | 3.043 (3) | 152 (3) |
O3—H3C···O1 | 0.89 (2) | 2.29 (3) | 2.982 (3) | 134 (3) |
Symmetry codes: (i) −x, −y+2, −z+1; (ii) x, y−1, z; (iii) −x+1, −y+1, −z+2. |
References
Bruker (1997). SMART, SAINT and SHELXTL. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Gardner, T. S., Smith, F. A., Wenis, E. & Lee, J. (1956). J. Org. Chem. 21, 530–533. CrossRef CAS Web of Science Google Scholar
Hadjoudis, E., Vittorakis, M. & Moustakali-Mavridis, I. (1987). Tetrahedron, 43, 1345–1360. CrossRef CAS Web of Science Google Scholar
Parashar, R. K., Sharma, R. C., Kumar, A. & Mohan, G. (1988). Inorg. Chim. Acta, 151, 201–208. CrossRef CAS Web of Science Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (1997). SHELXS97 and SHELXL97. University of Göttingen, Germany. Google Scholar
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Hydrazonecarbonyl compounds have received considerable attention due to their pharmacological activities (Parashar et al., 1988) and photochromic properties (Hadjoudis et al., 1987). A series of similar pyrazinylcarboxylic acid hydrazones has been reported previously (Gardner et al., 1956). As a continuation of the work of our group, we report here the crystal structure of 2'-(3-hydroxybenzylidene)pyrazine-2-carbohydrazide monohydrate, (I).
The asymmetric unit contains one organic molecule and one molecule of H2O. The carbohydrazide molecule deviates only slightly from planarity with a dihedral angle of 11.60 (3)° between the planes of the pyrazinyl and phenyl rings (Fig. 1).
In the crystal, the organic molecules of (I) are arranged in slightly tilted rows. Within the rows, amide atom N3 acts as a hydrogen bond donor to the atom O2 of the hydroxy group in a neighbouring molecule, thereby forming extended chains, which run parallel to the a axis (Table 1, Fig. 2).
The water O atom acts as a hydrogen bond acceptor from the hydroxy group of an organic molecule. One water H atom forms a hydrogen bond with the N atom in the pyrazinyl ring of another adjacent molecule, while the other H atom forms bifurcated hydrogen bonds with the carbonyl O atom, O1, and the N4 atom from another molecule of I, thereby forming a five-membered hydrogen bond ring (Fig. 3).
The crystal packing is characterized by π···π stacking interactions. The molecules are stacked in an antiparalled fashion, with a pyrazinyl to phenyl ring centroid-centroid separation of 3.669 (2) Å and an offset of 1.362 Å. Together with the hydrogen bonds, these interactions lead to a three-dimensional supramolecular network pattern (Fig. 3).