organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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N′-Hy­dr­oxy­pyridine-2-carboximidamide

aDepartment of Studies and Research in Chemistry, U.C.S, Tumkur University, Tumkur, Karnataka 572 103, India, bDepartment of Studies and Research in Chemistry, Tumkur University, Tumkur, Karnataka 572 103, India, cDepartment of Studies and Research in Physics, U.C.S, Tumkur University, Tumkur, Karnataka 572 103, India, dTadimety Aromatics Pvt Ltd, Hirehally Industrial Area, Tumkur, Karnataka 572 168, India, and eSoild State and Structural Chemistry Unit, Indian Institute of Science, Bangalore, Karnataka 560 012, India
*Correspondence e-mail: drsreenivasa@yahoo.co.in

(Received 13 June 2013; accepted 24 June 2013; online 29 June 2013)

The title mol­ecule, C6H7N3O, is almost planar (r.m.s. deviation = 0.0068 Å) and adopts an E conformation about the C=N double bond. In the crystal, mol­ecules are linked by pairs of strong N—H⋯N hydrogen bonds, forming inversion dimers with R22(10) motifs. The dimers are further linked into C(3) chains through O—H⋯N hydrogen bonds.

Related literature

For the pharmaceutical and biological activity of substituted N′-hy­droxy­benzamidines and 1,2,4-oxa­diazole derivatives, see: Kundu et al. (2012[Kundu, M., Singh, J., Singh, B., Ghosh, T., Maiti, B. C. & Maity, T. K. (2012). Indian J. Chem. Sect. B, 51, 493-497.]); Sakamoto et al. (2007[Sakamoto, T., Cullen, M. D., Hartman, T. L., Watson, K. M., Buckheit, R. W., Pannecouque, C., DeClercq, E. & Cushman, M. (2007). J. Med. Chem. 50, 3314-3319.]); Tyrkov & Sukhenko (2004[Tyrkov, A. G. & Sukhenko, L. T. (2004). Pharm. Chem. J.. 38(7), 30-38.]). For a related structure, see: Sreenivasa et al. (2012[Sreenivasa, S., ManojKumar, K. E., Suchetan, P. A., Mohan, N. R. & Palakshamurthy, B. S. (2012). Acta Cryst. E68, o3402.])

[Scheme 1]

Experimental

Crystal data
  • C6H7N3O

  • Mr = 137.15

  • Monoclinic, C 2/c

  • a = 21.367 (5) Å

  • b = 4.6382 (11) Å

  • c = 13.003 (3) Å

  • β = 105.468 (12)°

  • V = 1242.0 (5) Å3

  • Z = 8

  • Mo Kα radiation

  • μ = 0.11 mm−1

  • T = 293 K

  • 0.33 × 0.25 × 0.20 mm

Data collection
  • Bruker APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2, SADABS, SAINT-Plus and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.966, Tmax = 0.979

  • 8242 measured reflections

  • 1086 independent reflections

  • 982 reflections with I > 2σ(I)

  • Rint = 0.038

Refinement
  • R[F2 > 2σ(F2)] = 0.031

  • wR(F2) = 0.081

  • S = 1.08

  • 1086 reflections

  • 103 parameters

  • 2 restraints

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.19 e Å−3

  • Δρmin = −0.18 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
O1—H1⋯N3i 0.903 (18) 1.859 (19) 2.7537 (14) 170.5 (17)
N2—H2N2⋯N1ii 0.86 (1) 2.44 (1) 3.1753 (16) 144 (1)
Symmetry codes: (i) [-x+{\script{1\over 2}}, y+{\script{1\over 2}}, -z+{\script{1\over 2}}]; (ii) -x, -y, -z.

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2, SADABS, SAINT-Plus and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: APEX2 and SAINT-Plus (Bruker, 2009[Bruker (2009). APEX2, SADABS, SAINT-Plus and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT-Plus and XPREP (Bruker, 2009[Bruker (2009). APEX2, SADABS, SAINT-Plus and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: Mercury (Macrae et al., 2008[Macrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466-470.]); software used to prepare material for publication: SHELXL97.

Supporting information


Comment top

Substituted N'-hydroxybenzamidines are important intermediates obtained during the synthesis of pharmaceutically important 1,2,4-oxadiazole derivatives (Kundu et al., 2012). 1,2,4-Oxadiazole derivatives are well known for their biological activities such as anti-HIV (Sakamoto et al., 2007) and anti-microbial (Tyrkov et al., 2004). In this view, we synthesized the title compound to study its crystal structure.

The title compound, (I), crystalizes with a single molecule in the asymmetric unit. This is in contrast to (E)-3-chloro-N'-hydroxybenzene-1-carboximidamide, (II), (Sreenivasa et al., 2012) which crystalizes with two molecules in its asymmetric unit. Compound (I) adopts an E configuration across the C=N double bond, as the OH group and the benzene ring are on opposite sides of the double bond, while the H atom of the hydroxy group is directed away from the NH2 group. This is similar as observed in (II). In the packing, the molecules are linked to one another through strong intermolecular N—H···N hydrogen bonds into R22(10) motifs forming inversion dimers. The dimers are further linked into C(3) chains through O—H···N hydrogen bonds.

Related literature top

For the pharmaceutical and biological activity of substituted N'-hydroxybenzamidines and 1,2,4-oxadiazole derivatives, see: Kundu et al. (2012); Sakamoto et al. (2007); Tyrkov & Sukhenko (2004). For a related structure, see: Sreenivasa et al. (2012)

Experimental top

To a solution of 2-cyanopyridine (1 mmol) in ethanol was added triethyl amine (2.5 mmol) and hydroxyl amine hydrochloride, NH2OH.HCl (3.5 mmol). The reaction mixture was stirred at room temperature for 12hrs. (The reaction was monitored by TLC). The solvent was removed and the crude product was purified by column chromatography using hexane and ethyl acetate as the eluent.

Single crystals required for X-ray diffraction measurements were obtained from slow evaporation of the solution of the compound in a mixture of ethanol and dichloromethane (1:4).

Refinement top

The hydrogen atoms attached to N and O were located in difference maps and refined isotropically. The remaining H atoms were positioned geometrically and refined using a riding model, with C–H = 0.93 Å with isotropic displacement parameters set to 1.2 times of the Ueq of the parent atom.

Structure description top

Substituted N'-hydroxybenzamidines are important intermediates obtained during the synthesis of pharmaceutically important 1,2,4-oxadiazole derivatives (Kundu et al., 2012). 1,2,4-Oxadiazole derivatives are well known for their biological activities such as anti-HIV (Sakamoto et al., 2007) and anti-microbial (Tyrkov et al., 2004). In this view, we synthesized the title compound to study its crystal structure.

The title compound, (I), crystalizes with a single molecule in the asymmetric unit. This is in contrast to (E)-3-chloro-N'-hydroxybenzene-1-carboximidamide, (II), (Sreenivasa et al., 2012) which crystalizes with two molecules in its asymmetric unit. Compound (I) adopts an E configuration across the C=N double bond, as the OH group and the benzene ring are on opposite sides of the double bond, while the H atom of the hydroxy group is directed away from the NH2 group. This is similar as observed in (II). In the packing, the molecules are linked to one another through strong intermolecular N—H···N hydrogen bonds into R22(10) motifs forming inversion dimers. The dimers are further linked into C(3) chains through O—H···N hydrogen bonds.

For the pharmaceutical and biological activity of substituted N'-hydroxybenzamidines and 1,2,4-oxadiazole derivatives, see: Kundu et al. (2012); Sakamoto et al. (2007); Tyrkov & Sukhenko (2004). For a related structure, see: Sreenivasa et al. (2012)

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: APEX2 and SAINT-Plus (Bruker, 2009); data reduction: SAINT-Plus and XPREP (Bruker, 2009); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: Mercury (Macrae et al., 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure of the title compound, showing the atom-labeling scheme. Displacement ellipsoids are drawn at the 50% probability level.
[Figure 2] Fig. 2. Packing of molecules displaying R22(10) loops and C(3) chains.
N'-Hydroxypyridine-2-carboximidamide top
Crystal data top
C6H7N3OF(000) = 576
Mr = 137.15prism
Monoclinic, C2/cDx = 1.467 Mg m3
Hall symbol: -C 2ycMo Kα radiation, λ = 0.71073 Å
a = 21.367 (5) ÅCell parameters from 1088 reflections
b = 4.6382 (11) Åθ = 2.0–25.0°
c = 13.003 (3) ŵ = 0.11 mm1
β = 105.468 (12)°T = 293 K
V = 1242.0 (5) Å3Prism, colourless
Z = 80.33 × 0.25 × 0.20 mm
Data collection top
Bruker APEXII CCD area-detector
diffractometer
1086 independent reflections
Radiation source: fine-focus sealed tube982 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.038
Detector resolution: 1.03 pixels mm-1θmax = 25.0°, θmin = 2.0°
phi and ω scansh = 2424
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
k = 55
Tmin = 0.966, Tmax = 0.979l = 1515
8242 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.081H atoms treated by a mixture of independent and constrained refinement
S = 1.08 w = 1/[σ2(Fo2) + (0.0379P)2 + 0.8786P]
where P = (Fo2 + 2Fc2)/3
1086 reflections(Δ/σ)max = 0.011
103 parametersΔρmax = 0.19 e Å3
2 restraintsΔρmin = 0.18 e Å3
0 constraints
Crystal data top
C6H7N3OV = 1242.0 (5) Å3
Mr = 137.15Z = 8
Monoclinic, C2/cMo Kα radiation
a = 21.367 (5) ŵ = 0.11 mm1
b = 4.6382 (11) ÅT = 293 K
c = 13.003 (3) Å0.33 × 0.25 × 0.20 mm
β = 105.468 (12)°
Data collection top
Bruker APEXII CCD area-detector
diffractometer
1086 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2009)
982 reflections with I > 2σ(I)
Tmin = 0.966, Tmax = 0.979Rint = 0.038
8242 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0312 restraints
wR(F2) = 0.081H atoms treated by a mixture of independent and constrained refinement
S = 1.08Δρmax = 0.19 e Å3
1086 reflectionsΔρmin = 0.18 e Å3
103 parameters
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
xyzUiso*/Ueq
O10.19134 (4)0.1826 (2)0.26040 (7)0.0207 (3)
H1N20.0896 (7)0.225 (3)0.1797 (12)0.027 (4)*
H2N20.0456 (6)0.081 (3)0.0861 (11)0.027 (4)*
H10.2316 (9)0.260 (4)0.2779 (14)0.043 (5)*
C10.12315 (6)0.2716 (3)0.03188 (9)0.0154 (3)
C20.17439 (6)0.4236 (3)0.01036 (10)0.0189 (3)
H20.21670.39640.05200.023*
C30.16144 (6)0.6149 (3)0.07361 (10)0.0208 (3)
H30.19490.71640.09040.025*
C40.09770 (6)0.6536 (3)0.13259 (10)0.0211 (3)
H40.08740.78340.18910.025*
C50.05004 (6)0.4948 (3)0.10538 (10)0.0203 (3)
H50.00730.52290.14490.024*
C60.13390 (5)0.0595 (3)0.12070 (9)0.0147 (3)
N10.06133 (5)0.3023 (2)0.02561 (8)0.0176 (3)
N20.08163 (5)0.0824 (2)0.13540 (9)0.0179 (3)
N30.19228 (5)0.0259 (2)0.18081 (8)0.0175 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0156 (5)0.0240 (5)0.0199 (5)0.0027 (4)0.0004 (4)0.0070 (4)
C10.0157 (6)0.0151 (6)0.0149 (6)0.0009 (5)0.0032 (5)0.0048 (5)
C20.0152 (6)0.0215 (7)0.0186 (6)0.0008 (5)0.0022 (5)0.0038 (5)
C30.0225 (7)0.0210 (7)0.0205 (7)0.0050 (5)0.0087 (5)0.0035 (5)
C40.0276 (7)0.0199 (7)0.0157 (6)0.0005 (5)0.0055 (5)0.0008 (5)
C50.0175 (6)0.0231 (7)0.0173 (6)0.0017 (5)0.0006 (5)0.0008 (5)
C60.0142 (6)0.0154 (6)0.0141 (6)0.0000 (5)0.0029 (5)0.0046 (5)
N10.0155 (5)0.0193 (6)0.0162 (5)0.0008 (4)0.0012 (4)0.0004 (4)
N20.0130 (6)0.0216 (6)0.0162 (6)0.0013 (5)0.0009 (5)0.0031 (5)
N30.0163 (5)0.0177 (6)0.0169 (5)0.0009 (4)0.0018 (4)0.0017 (4)
Geometric parameters (Å, º) top
O1—N31.4201 (13)C4—C51.3773 (18)
O1—H10.903 (18)C4—H40.9300
C1—N11.3407 (16)C5—N11.3408 (16)
C1—C21.3918 (17)C5—H50.9300
C1—C61.4878 (17)C6—N31.2928 (16)
C2—C31.3765 (18)C6—N21.3532 (16)
C2—H20.9300N2—H1N20.862 (13)
C3—C41.3849 (19)N2—H2N20.859 (13)
C3—H30.9300
N3—O1—H1104.9 (11)C3—C4—H4120.9
N1—C1—C2123.03 (11)N1—C5—C4124.19 (12)
N1—C1—C6115.35 (10)N1—C5—H5117.9
C2—C1—C6121.61 (11)C4—C5—H5117.9
C3—C2—C1118.91 (12)N3—C6—N2123.75 (11)
C3—C2—H2120.5N3—C6—C1118.26 (10)
C1—C2—H2120.5N2—C6—C1117.97 (10)
C2—C3—C4118.86 (12)C1—N1—C5116.69 (10)
C2—C3—H3120.6C6—N2—H1N2116.3 (10)
C4—C3—H3120.6C6—N2—H2N2119.9 (10)
C5—C4—C3118.28 (12)H1N2—N2—H2N2118.9 (14)
C5—C4—H4120.9C6—N3—O1108.89 (9)
N1—C1—C2—C30.07 (18)N1—C1—C6—N20.29 (16)
C6—C1—C2—C3179.35 (11)C2—C1—C6—N2179.05 (11)
C1—C2—C3—C41.19 (18)C2—C1—N1—C51.51 (17)
C2—C3—C4—C50.96 (18)C6—C1—N1—C5179.17 (10)
C3—C4—C5—N10.6 (2)C4—C5—N1—C11.77 (18)
N1—C1—C6—N3178.22 (10)N2—C6—N3—O10.96 (16)
C2—C1—C6—N32.45 (17)C1—C6—N3—O1179.38 (9)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N3i0.903 (18)1.859 (19)2.7537 (14)170.5 (17)
N2—H2N2···N1ii0.86 (1)2.44 (1)3.1753 (16)144 (1)
Symmetry codes: (i) x+1/2, y+1/2, z+1/2; (ii) x, y, z.

Experimental details

Crystal data
Chemical formulaC6H7N3O
Mr137.15
Crystal system, space groupMonoclinic, C2/c
Temperature (K)293
a, b, c (Å)21.367 (5), 4.6382 (11), 13.003 (3)
β (°) 105.468 (12)
V3)1242.0 (5)
Z8
Radiation typeMo Kα
µ (mm1)0.11
Crystal size (mm)0.33 × 0.25 × 0.20
Data collection
DiffractometerBruker APEXII CCD area-detector
Absorption correctionMulti-scan
(SADABS; Bruker, 2009)
Tmin, Tmax0.966, 0.979
No. of measured, independent and
observed [I > 2σ(I)] reflections
8242, 1086, 982
Rint0.038
(sin θ/λ)max1)0.594
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.081, 1.08
No. of reflections1086
No. of parameters103
No. of restraints2
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.19, 0.18

Computer programs: APEX2 (Bruker, 2009), APEX2 and SAINT-Plus (Bruker, 2009), SAINT-Plus and XPREP (Bruker, 2009), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), Mercury (Macrae et al., 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H1···N3i0.903 (18)1.859 (19)2.7537 (14)170.5 (17)
N2—H2N2···N1ii0.859 (13)2.438 (14)3.1753 (16)144.3 (13)
Symmetry codes: (i) x+1/2, y+1/2, z+1/2; (ii) x, y, z.
 

Acknowledgements

The authors thank Dr S. C. Sharma, Ex-Vice Chancellor, Tumkur University, Tumkur, for his constant encouragement, and Professor T. N. Guru Row, S. S. C. U, Indian Institute of Science, Bangalore, for his guidance and support.

References

First citationBruker (2009). APEX2, SADABS, SAINT-Plus and XPREP. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationKundu, M., Singh, J., Singh, B., Ghosh, T., Maiti, B. C. & Maity, T. K. (2012). Indian J. Chem. Sect. B, 51, 493–497.  Google Scholar
First citationMacrae, C. F., Bruno, I. J., Chisholm, J. A., Edgington, P. R., McCabe, P., Pidcock, E., Rodriguez-Monge, L., Taylor, R., van de Streek, J. & Wood, P. A. (2008). J. Appl. Cryst. 41, 466–470.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
First citationSakamoto, T., Cullen, M. D., Hartman, T. L., Watson, K. M., Buckheit, R. W., Pannecouque, C., DeClercq, E. & Cushman, M. (2007). J. Med. Chem. 50, 3314–3319.  Web of Science CrossRef PubMed CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationSreenivasa, S., ManojKumar, K. E., Suchetan, P. A., Mohan, N. R. & Palakshamurthy, B. S. (2012). Acta Cryst. E68, o3402.  CSD CrossRef IUCr Journals Google Scholar
First citationTyrkov, A. G. & Sukhenko, L. T. (2004). Pharm. Chem. J.. 38(7), 30–38.  Google Scholar

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