4-{(Z)-(sec-Butyl­amino)(phen­yl)methyl­ene}-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

Hai-Zhen Xu; Jian-Ping Xu; Yan-Wei Yuan; Jin Zhang; You-Quan Zhu

doi:10.1107/S160053680902950X

. 2009 Aug 8;65(Pt 9):o2116. doi: 10.1107/S160053680902950X

4-{(Z)-(sec-Butylamino)(phenyl)methylene}-3-methyl-1-phenyl-1H-pyrazol-5(4H)-one

Hai-Zhen Xu ^a,^*, Jian-Ping Xu ^b, Yan-Wei Yuan ^c, Jin Zhang ^c, You-Quan Zhu ^c

PMCID: PMC2970147 PMID: 21577531

Abstract

In the title compound, C₂₁H₂₃N₃O, the dihedral angles formed by the pyrazolone ring with two phenyl rings are 10.38 (8) and 76.94 (6)°. The sec-butylamino group is disordered over two positions, with refined site-occupancy factors of 0.730 (4) and 0.270 (4). The compound could potentially be ligand stabilized in the solid state in a keto–enamine tautomeric form. The amine functionality is involved in an intramolecular N—H⋯O hydrogen bond, while weak intermolecular C—H⋯O and C—H⋯N hydrogen bonds participate in the formation of the crystal structure.

Related literature

For the antibacterial, biological and analgesic activity of metal complexes of 1-phenyl-3-methyl-4-benzoylpyrazolon-5-one, see: Li et al. (1997 ▶); Liu et al. (1980 ▶); Zhou et al. (1999 ▶).

Experimental

Crystal data

C₂₁H₂₃N₃O
M _r = 333.42
Triclinic,
a = 9.3631 (19) Å
b = 10.077 (2) Å
c = 10.687 (2) Å
α = 107.07 (3)°
β = 100.30 (3)°
γ = 100.14 (3)°
V = 920.0 (4) Å³
Z = 2
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 113 K
0.20 × 0.18 × 0.16 mm

Data collection

Rigaku Saturn CCD area-detector diffractometer
Absorption correction: multi-scan (CrystalClear; Rigaku, 2005 ▶) T _min = 0.985, T _max = 0.988
8309 measured reflections
4296 independent reflections
2944 reflections with I > 2σ(I)
R _int = 0.026

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.135
S = 1.08
4296 reflections
272 parameters
16 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.32 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: CrystalClear (Rigaku, 2005 ▶); 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: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680902950X/bh2238sup1.cif

e-65-o2116-sup1.cif^{(23.6KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S160053680902950X/bh2238Isup2.hkl

e-65-o2116-Isup2.hkl^{(210.5KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Enhanced figure: interactive version of Fig. 1

Table 1. Selected bond lengths (Å).

O1—C7	1.2529 (17)
C7—C8	1.4382 (19)
C8—C11	1.402 (2)
C11—N3′	1.311 (5)
C11—N3	1.359 (2)

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Table 2. Hydrogen-bond geometry (Å, °).

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N3′—H3′⋯O1	0.904 (10)	1.99 (4)	2.705 (6)	135 (5)
N3—H3⋯O1	0.902 (10)	1.933 (15)	2.699 (2)	141.6 (18)
C16—H16A⋯O1ⁱ	0.95	2.53	3.2743 (19)	135
C13—H13A⋯N2ⁱⁱ	0.95	2.60	3.537 (2)	167

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

Acknowledgments

The authors gratefully acknowledge financial support from 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 C1···C6 and C12···C17 are 10.38 (8) and 76.94 (6)°, respectively. The O atom of the 3-methyl-1-phenylpyrazol-5-one moiety and the N atom of the sec-butylamino group are available for coordination with metals. The pyrazole ring is planar and atoms O1, C7, C8, C11 and N3 (or N3') are almost coplanar, the largest deviation being 0.0323 (13) Å [or 0.201 (3) Å] for atom C11. The dihedral angle between this mean plane and the pyrazoline ring of PMBP is 3.00 (11)° [or 12.10 (18)°]. The bond lengths within this part of the molecule (Table 1) lie between classical single- and double-bond lengths, indicating extensive conjugation. A strong intramolecular N3—H3···O1 hydrogen bond (Table 2) is observed, leading to a keto-enamine form. The molecule is further stabilized by C—H···O and C—H···N intramolecular hydrogen bonds (Table 2), while the crystal structure includes C—H···O and C—H···N intermolecular hydrogen bonds (Table 2 and Fig. 2).

Experimental

Compound (I) was synthesized by refluxing a mixture of 1-phenyl-3- methyl-4-benzoylpyrazol-5-one (10 mmol) and sec-butylamine (10 mmol) in ethanol (80 ml) over a steam bath for about 4 h. Excess solvent was removed by evaporation and the solution was cooled to room temperature. After 2 days a yellow solid was obtained and this was dried in air. The product was recrystallized from ethanol, to afford yellow crystals of (I) suitable for X-ray analysis.