(E)-3-Amino-4-(2-phenyl­hydrazinyl­idene)-1H-pyrazol-5(4H)-one

Galal H Elgemeie; Shahinaz H Sayed; Peter G Jones

doi:10.1107/S1600536812050854

. 2013 Jan 4;69(Pt 2):o187. doi: 10.1107/S1600536812050854

(E)-3-Amino-4-(2-phenylhydrazinylidene)-1H-pyrazol-5(4H)-one

Galal H Elgemeie ^a,^*, Shahinaz H Sayed ^a, Peter G Jones ^b

PMCID: PMC3569249 PMID: 23424472

Abstract

The molecule of the title compound, C₉H₉N₅O, is essentially planar (r.m.s. deviation of all atoms = 0.02 Å) except for the NH₂ H atoms. An intramolecular hydrazinylidene–carbonyl N—H⋯O=C hydrogen bond is present. In the crystal, molecules are connected via N—H⋯N/O hydrogen bonds, forming thick layers parallel to (100).

Related literature

The synthesis, chemistry and biological/medical activity of related compounds is described in: Elgemeie (2003 ▶); Elgemeie & El-Aziz (2002 ▶); Elgemeie & Sood (2003 ▶, 2006 ▶); Elgemeie et al. (2001 ▶, 2007 ▶, 2008 ▶, 2009 ▶).

Experimental

Crystal data

C₉H₉N₅O
M _r = 203.21
Monoclinic,
a = 6.7380 (2) Å
b = 13.4310 (4) Å
c = 10.4563 (3) Å
β = 103.094 (3)°
V = 921.67 (5) Å³
Z = 4
Cu Kα radiation
μ = 0.86 mm⁻¹
T = 100 K
0.15 × 0.10 × 0.03 mm

Data collection

Oxford Diffraction Xcalibur (Atlas, Nova) diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 ▶) T _min = 0.668, T _max = 1.000
26682 measured reflections
1914 independent reflections
1807 reflections with I > 2σ(I)
R _int = 0.029

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.087
S = 1.05
1914 reflections
152 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.26 e Å⁻³

Data collection: CrysAlis PRO (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP in SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Click here for additional data file.^{(19.6KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812050854/gg2105sup1.cif

e-69-0o187-sup1.cif^{(19.6KB, cif)}

Click here for additional data file.^{(94.2KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812050854/gg2105Isup3.hkl

e-69-0o187-Isup3.hkl^{(94.2KB, hkl)}

Click here for additional data file.^{(4.1KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812050854/gg2105Isup3.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
N1—H01⋯O1ⁱ	0.909 (16)	1.949 (16)	2.8521 (11)	172.0 (14)
N3—H03B⋯N2ⁱⁱ	0.934 (17)	2.424 (16)	3.2711 (12)	150.8 (13)
N3—H03A⋯O1ⁱⁱⁱ	0.908 (16)	2.141 (15)	2.9635 (11)	150.2 (13)
N5—H05⋯O1	0.897 (16)	2.174 (16)	2.8575 (11)	132.5 (13)

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

supplementary crystallographic information

Comment

Chemically synthesized purine analogues find numerous applications in clinical medicine and medical research (Elgemeie, 2003; Elgemeie et al., 2008). The pharmacological approach involves analogues in which the heterocyclic ring system has been modified so as to induce toxic effects when the analogue is incorporated into specific cell constituents (Elgemeie & El-Aziz, 2002). As part of our program directed towards the synthesis of purines and other antimetabolites (Elgemeie et al., 2001, 2009), we have recently reported various successful approaches to the syntheses of purine analogues. Derivatives of these ring systems are of interest as antimetabolites in biochemical reactions (Elgemeie & Sood, 2003). We have described several novel syntheses of functionalized pyrazoles (Elgemeie et al., 2007). These compounds are considered important intermediates for the synthesis of various purine ring systems (Elgemeie & Sood, 2006). As a continuation of this work, the title pyrazole compound (2), was prepared as a precursor for the synthesis of other purines. 2-Hydrazinyl-2-oxo-N-phenylacetohydrazonoyl cyanide (1) undergoes intramolecular cyclization by refluxing in ethanol containing catalytic amounts of piperidine to give the novel pyrazole derivative (2). The title compound can potentially exist in two other tautomeric forms with hydroxyl groups, (3) and (4). Spectral studies, however, indicated the presence of the ketonic tautomer (2) in solution (e.g. the ¹³C NMR signal at δ = 174.00, indicating a carbonyl carbon rather than C—OH.

The X-ray analysis of (2) (Fig. 1) establishes the exclusive presence of the keto tautomer in the solid state; all H atoms could be located unambiguously and bond lengths are also consistent with the keto form. The entire molecule is planar (r.m.s. deviation of all non-C atoms: 0.02 Å), except for the H atoms of the NH₂ group; H03A lies 0.36 (2) and H03B 0.27 (2) Å outside the plane. Consistent with the E configuration, an intramolecular hydrogen bond N5—H05···O1 is observed.

The molecules are connected by hydrogen bonds #1–#3 to form thick hydrogen-bonded layers parallel to (100); the individual molecules are to a good approximation oriented in the planes (042) (Figs. 2, 3). Hydrogen bond #4 is the second and appreciably less linear branch of a three-centre interaction.

Experimental

The title compound was obtained by refluxing an ethanolic solution of 2-hydrazinyl-2-oxo-N-phenylacetohydrazonoyl cyanide containing a few drops of piperidine for 1 h. After cooling, the precipitate was filtered off and recrystallized from ethanol. Yield (85%); m.p. 245 °C; IR (KBr) ν = 3450, 3350, 3300 (NH₂, NH), 1660 (C═O, s) cm^-1; ¹H NMR (DMSO) δ = 6.88 (s, br, 2H, NH₂), 7.23 (s, br, 1H, NH), 7.41–7.92 (m, 5H, C₆H₅); MS, m/z = 203; Calc. for C₉H₉N₅O: C, 53.19; H, 4.46; N, 34.46; O, 7.87. Found: C, 53.56; H, 4.57; N, 34.62; O, 7.61%.