4-[(Z)-Allyl­amino­(phen­yl)methyl­ene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

Hai-Zhen Xu; Yan-Xia Yang; Jing Yan; You-Quan Zhu

doi:10.1107/S160053681001384X

. 2010 May 12;66(Pt 6):o1309. doi: 10.1107/S160053681001384X

4-[(Z)-Allylamino(phenyl)methylene]-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

Hai-Zhen Xu ^a,^*, Yan-Xia Yang ^b, Jing Yan ^a, You-Quan Zhu ^c,^*

PMCID: PMC2979603 PMID: 21579404

Abstract

The title compound, C₂₀H₁₉N₃O, exists in a keto–enamine tautomeric form. The pyrazolone ring makes dihedral angles of 20.52 (10) and 77.73 (5)° with the two phenyl rings and an intramolecular N—H⋯O hydrogen bond occurs. A weak intermolecular C—H⋯O hydrogen bond is observed in the crystal structure. The allyl group is disordered over two positions, with site-occupancy factors of 0.533 (5) and 0.467 (5).

Related literature

For the analgesic activity of metal complexes with 1-phenyl-3-methyl-4-benzoylpyrazolon-5-one, see: Li et al. (1997 ▶); Liu et al. (1980 ▶); Zhou et al. (1999 ▶). For related structures, see: Bao et al. (2004 ▶); Sun et al. (2007 ▶); Zhu et al. (2005 ▶).

Experimental

Crystal data

C₂₀H₁₉N₃O
M _r = 317.38
Triclinic,
a = 9.295 (1) Å
b = 9.8440 (12) Å
c = 10.0670 (14) Å
α = 86.175 (8)°
β = 89.280 (9)°
γ = 74.329 (7)°
V = 884.90 (19) Å³
Z = 2
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 293 K
0.22 × 0.18 × 0.16 mm

Data collection

Rigaku Saturn724 CCD camera diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2009 ▶) T _min = 0.984, T _max = 0.988
10726 measured reflections
3910 independent reflections
2135 reflections with I > 2σ(I)
R _int = 0.032

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.133
S = 0.94
3910 reflections
242 parameters
16 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.17 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: CrystalClear (Rigaku, 2009 ▶); cell refinement: CrystalClear; data reduction: CrystalClear; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: CrystalStructure (Rigaku, 2009 ▶); software used to prepare material for publication: CrystalStructure.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053681001384X/is2538sup1.cif

e-66-o1309-sup1.cif^{(21.4KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053681001384X/is2538Isup2.hkl

e-66-o1309-Isup2.hkl^{(191.6KB, 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
N3—H3⋯O1	1.06 (2)	1.75 (2)	2.687 (2)	145 (2)
C17—H17⋯O1ⁱ	0.95	2.41	3.345 (2)	168

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors gratefully acknowledge the financial support of the National Natural Science Foundation of China (grant No. 20772066).

supplementary crystallographic information

Comment

1-Phenyl-3-methyl-4-benzoylpyrazolon-5-one (HPMBP), an effective β-diketonate, is widely used and well known for its extractive ability. In recent years, HPMBP and its metal complexes have also been found to have good antibacterial and biological properties. Its metal complexes have analgesic activity (Liu et al., 1980; Li et al., 1997; Zhou et al., 1999). In order to develop new medicines, we have synthesized the title compound, (I), and its structure is reported here.

The structure of (I) is shown in Fig. 1. The dihedral angles formed by the pyrazolone ring with the two phenyl rings C5–C10 and C12–C17 are 20.52 (10) and 77.73 (5)°, respectively. The O atom of the 3-methyl-1-phenylpyrazol-5-one moiety and the N atom of the allylamino group are available for coordination with metals. The pyrazole ring is planar and atoms O1, C1, C2, C11 and N3 are almost coplanar, the largest deviation being 0.0195 (11) Å for atom C11. The dihedral angle between this mean plane and the pyrazoline ring of PMBP is 2.01 (12)°. The bond lengths within this part of the molecule lie between classical single- and double-bond lengths, indicating extensive conjugation. A strong intramolecular N3—H3···O1 hydrogen bond (Table 1) is observed, leading to a keto-enamine form. The crystal structure includes intermolecular C—H···O hydrogen bonds (Table 1 and Fig. 2).

Experimental

Compound (I) was synthesized by refluxing a mixture of 1-phenyl-3-methyl-4-benzoylpyrazol-5-one (10 mmol) and allylamine (10 mmol) in ethanol (80 ml) over a steam bath for about 10 h. Excess solvent was removed by evaporation and the solution was cooled to room temperature. After 4 d, a colorless solid was obtained and this was dried in air. The product was recrystallized from ethanol, to afford colorless crystals of (I) suitable for X-ray analysis.