(Z)-4-[2-(2,4-Dimethyl­phen­yl)hydrazinyl­idene]-3-methyl­pyrazol-5(1H)-one

Abstract

The mol­ecule of the title compound, C₁₂H₁₄N₄O, is roughly planar, with a dihedral angle of 8.0 (8)° between the benzene and pyrazole rings, and an intra­molecular N—H⋯O hydrogen bond forms an S(6) ring motif. In the crystal, mol­ecules are linked into an inversion dimer by a pair of N—H⋯O hydrogen bonds, which form an R ₂ ²(8) ring motif.

Related literature  

For the biological activity of pyrazolo­nes, see: Amir & Kumar (2005 ▶); Rao et al. (2008 ▶); Samshuddin et al. (2011 ▶). For the radical scavenging capacity of pyrazol-5-ols, see: Sarojini et al. (2010 ▶). For related structures, see: Butcher et al. (2011 ▶); Samshuddin et al. (2011 ▶). For reference bond-length data, see: Allen et al. (1987 ▶).

Experimental  

Crystal data  

• C₁₂H₁₄N₄O

• M _r = 230.27

• Monoclinic,

• a = 5.2926 (2) Å

• b = 22.1675 (6) Å

• c = 10.0529 (3) Å

• β = 101.770 (3)°

• V = 1154.64 (6) ų

• Z = 4

• Cu Kα radiation

• μ = 0.72 mm⁻¹

• T = 123 K

• 0.51 × 0.24 × 0.08 mm

Data collection  

• Agilent Xcalibur (Ruby, Gemini) diffractometer

• Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012 ▶) T _min = 0.538, T _max = 0.944

• 4152 measured reflections

• 2328 independent reflections

• 2061 reflections with I > 2σ(I)

• R _int = 0.024

Refinement  

• R[F ² > 2σ(F ²)] = 0.043

• wR(F ²) = 0.124

• S = 1.05

• 2328 reflections

• 157 parameters

• H-atom parameters constrained

• Δρ_max = 0.34 e Å⁻³

• Δρ_min = −0.27 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2012 ▶); cell refinement: CrysAlis PRO ; data reduction: CrysAlis RED (Agilent, 2012 ▶); 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

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
N2—H2A⋯O1i	0.88	1.95	2.8233 (15)	172
N4—H4D⋯O1	0.88	2.00	2.7286 (15)	139

Symmetry code: (i) .

supplementary crystallographic information

Comment

In view of high medicinal value such as anti-inflammatory, analgesic (Amir & Kumar, 2005), antimicrobial (Samshuddin et al., 2011) and antiproliferative activity (Rao et al. 2008) of pyrazolones, it was thought worthwhile to synthesize compounds based on pyrazolone derivatives. In addition, the radical scavenging capacity and molecular binding of various derivatives of pyrazol-5-ols were reported (Sarojini et al., 2010). Also, the crystal structures of some of the related pyrazoles viz. 3,5-bis(4-bromophenyl)-1-phenyl-4,5-dihydro-1H-pyrazole (Samshuddin et al., 2011) and 5-bis(4-methylphenyl)-1-phenyl-4,5-dihydro-1H-pyrazole (Butcher et al., 2011) have been reported. In view of the importance of pyrazolones, we report herein the crystal structure of the title compound, C₁₂H₁₄N₄O, (I).

The asymmetric unit of (I) consists of a 3-methyl-1H-pyrazol-5(4H)-one group bonded to 2,4-(dimethylphenyl)hydrazone in a nearly planar conformation (Fig. 1). The mean plane of the benzene ring is twisted by 8.0 (8)° from that of the pyrazole ring. Bond lengths are in normal ranges (Allen et al., 1987). In the crystal, intermolecular N2—H2A···O1 hydrogen bonds (Table 1) which form R²₂(8) ring motifs linking the molecule into dimers are observed (Fig. 2). An intramolecular N4—H4D···O1 hydrogen bond is also present.

Experimental

Ethyl 2-[2-(2,4-dimethylphenyl)hydrazinylidene]-3-oxobutanoate (2.62 g, 0.01 mol) and hydrazine hydrate (0.75 ml, 0.015 mol) were refluxed in acetic acid for 4–6 h. Then the reaction mixture was cooled to room temperature and the solid product was filtered off. Single crystals were grown by slow evaporation from a mixture of petroleum ether and ethyl acetate (1:3 v/v) (m.p. 421–423 K).

Refinement

All of the H atoms were placed in their calculated positions and then refined using the riding model with Atom—H lengths of 0.95 Å (CH), 0.98 Å (CH₃) or 0.88 Å (NH). Isotropic displacement parameters for these atoms were set to 1.2 (CH, NH) or 1.5 (CH₃) times U_eq of the parent atom.

Figures

Fig. 1.

Molecular structure of the title compound showing the atom labeling scheme and 30% probability displacement ellipsoids.

Fig. 2.

Packing diagram of the title compound viewed along the b axis. Dashed lines indicate intermolecular N—H···O hydrogen bonds which form R22(8) ring motifs linking the molecule into dimers. H atoms not involved in hydrogen bonding have been removed for clarity.

Crystal data

C12H14N4O	F(000) = 488
Mr = 230.27	Dx = 1.325 Mg m−3
Monoclinic, P21/c	Cu Kα radiation, λ = 1.54178 Å
Hall symbol: -P 2ybc	Cell parameters from 2088 reflections
a = 5.2926 (2) Å	θ = 4.0–75.3°
b = 22.1675 (6) Å	µ = 0.72 mm−1
c = 10.0529 (3) Å	T = 123 K
β = 101.770 (3)°	Long plate, colourless
V = 1154.64 (6) Å3	0.51 × 0.24 × 0.08 mm
Z = 4

Data collection

Agilent Xcalibur (Ruby, Gemini) diffractometer	2328 independent reflections
Radiation source: Enhance (Cu) X-ray Source	2061 reflections with I > 2σ(I)
Graphite monochromator	Rint = 0.024
Detector resolution: 10.5081 pixels mm-1	θmax = 75.5°, θmin = 4.0°
ω scans	h = −5→6
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2012)	k = −27→26
Tmin = 0.538, Tmax = 0.944	l = −11→12
4152 measured reflections

Refinement

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)] = 0.043	Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.124	H-atom parameters constrained
S = 1.05	w = 1/[σ2(Fo2) + (0.0699P)2 + 0.3531P] where P = (Fo2 + 2Fc2)/3
2328 reflections	(Δ/σ)max < 0.001
157 parameters	Δρmax = 0.34 e Å−3
0 restraints	Δρmin = −0.27 e Å−3

Special details

Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds 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 (Ų)

	x	y	z	Uiso*/Ueq
O1	0.18460 (18)	0.45530 (5)	0.89208 (10)	0.0213 (2)
N1	0.2909 (2)	0.61180 (5)	0.90296 (12)	0.0212 (3)
N2	0.1729 (2)	0.55870 (5)	0.93665 (12)	0.0206 (3)
H2A	0.0590	0.5581	0.9893	0.025*
N3	0.5733 (2)	0.50000 (5)	0.73044 (12)	0.0190 (3)
N4	0.5362 (2)	0.44146 (5)	0.73009 (12)	0.0196 (3)
H4D	0.4265	0.4266	0.7766	0.024*
C1	0.2517 (3)	0.50879 (6)	0.88022 (14)	0.0183 (3)
C2	0.4380 (3)	0.53140 (6)	0.80200 (14)	0.0186 (3)
C3	0.4473 (3)	0.59579 (6)	0.82398 (14)	0.0196 (3)
C4	0.6109 (3)	0.63998 (6)	0.76933 (16)	0.0242 (3)
H4A	0.6007	0.6793	0.8126	0.036*
H4B	0.5497	0.6438	0.6709	0.036*
H4C	0.7903	0.6260	0.7885	0.036*
C5	0.6657 (3)	0.40171 (6)	0.65796 (14)	0.0187 (3)
C6	0.6331 (3)	0.33981 (6)	0.67717 (14)	0.0190 (3)
C7	0.7561 (3)	0.29989 (6)	0.60384 (14)	0.0202 (3)
H7A	0.7338	0.2578	0.6145	0.024*
C8	0.9106 (3)	0.31954 (7)	0.51552 (14)	0.0208 (3)
C9	0.9423 (3)	0.38169 (7)	0.50101 (15)	0.0226 (3)
H9A	1.0493	0.3960	0.4425	0.027*
C10	0.8203 (3)	0.42275 (6)	0.57057 (14)	0.0216 (3)
H10A	0.8416	0.4648	0.5590	0.026*
C11	0.4740 (3)	0.31736 (6)	0.77591 (15)	0.0229 (3)
H11A	0.2952	0.3310	0.7465	0.034*
H11B	0.5452	0.3333	0.8667	0.034*
H11C	0.4783	0.2732	0.7785	0.034*
C12	1.0424 (3)	0.27468 (7)	0.43960 (16)	0.0259 (3)
H12A	0.9883	0.2337	0.4578	0.039*
H12B	1.2299	0.2783	0.4698	0.039*
H12C	0.9946	0.2829	0.3419	0.039*

Atomic displacement parameters (Ų)

	U11	U22	U33	U12	U13	U23
O1	0.0210 (5)	0.0191 (5)	0.0251 (5)	−0.0010 (4)	0.0078 (4)	−0.0011 (4)
N1	0.0195 (6)	0.0181 (6)	0.0257 (6)	0.0016 (4)	0.0038 (5)	0.0009 (5)
N2	0.0192 (6)	0.0197 (6)	0.0246 (6)	0.0005 (4)	0.0081 (5)	−0.0002 (4)
N3	0.0184 (5)	0.0176 (6)	0.0204 (6)	0.0011 (4)	0.0024 (4)	0.0006 (4)
N4	0.0190 (5)	0.0182 (6)	0.0226 (6)	−0.0010 (4)	0.0068 (4)	−0.0005 (4)
C1	0.0155 (6)	0.0201 (7)	0.0188 (6)	0.0016 (5)	0.0021 (5)	0.0004 (5)
C2	0.0168 (6)	0.0190 (6)	0.0193 (6)	0.0003 (5)	0.0023 (5)	0.0022 (5)
C3	0.0176 (6)	0.0185 (6)	0.0214 (6)	0.0034 (5)	0.0012 (5)	0.0014 (5)
C4	0.0228 (7)	0.0182 (6)	0.0320 (8)	0.0026 (5)	0.0066 (6)	0.0036 (6)
C5	0.0163 (6)	0.0203 (7)	0.0190 (6)	0.0006 (5)	0.0023 (5)	−0.0024 (5)
C6	0.0161 (6)	0.0209 (7)	0.0190 (6)	−0.0023 (5)	0.0015 (5)	−0.0010 (5)
C7	0.0184 (6)	0.0183 (7)	0.0224 (7)	−0.0018 (5)	0.0005 (5)	−0.0023 (5)
C8	0.0156 (6)	0.0242 (7)	0.0213 (6)	0.0004 (5)	0.0010 (5)	−0.0043 (5)
C9	0.0199 (6)	0.0269 (7)	0.0223 (7)	−0.0018 (6)	0.0073 (5)	−0.0003 (6)
C10	0.0228 (7)	0.0187 (6)	0.0233 (7)	−0.0010 (5)	0.0049 (5)	0.0002 (5)
C11	0.0257 (7)	0.0190 (6)	0.0255 (7)	−0.0037 (5)	0.0085 (6)	−0.0016 (5)
C12	0.0223 (7)	0.0256 (7)	0.0309 (7)	−0.0011 (6)	0.0079 (6)	−0.0080 (6)

Geometric parameters (Å, º)

O1—C1	1.2504 (17)	C5—C6	1.4013 (19)
N1—C3	1.3075 (19)	C6—C7	1.395 (2)
N1—N2	1.4059 (16)	C6—C11	1.5112 (18)
N2—C1	1.3475 (18)	C7—C8	1.394 (2)
N2—H2A	0.8800	C7—H7A	0.9500
N3—N4	1.3125 (16)	C8—C9	1.399 (2)
N3—C2	1.3135 (18)	C8—C12	1.5084 (19)
N4—C5	1.4052 (18)	C9—C10	1.385 (2)
N4—H4D	0.8800	C9—H9A	0.9500
C1—C2	1.4692 (18)	C10—H10A	0.9500
C2—C3	1.4437 (19)	C11—H11A	0.9800
C3—C4	1.4850 (19)	C11—H11B	0.9800
C4—H4A	0.9800	C11—H11C	0.9800
C4—H4B	0.9800	C12—H12A	0.9800
C4—H4C	0.9800	C12—H12B	0.9800
C5—C10	1.397 (2)	C12—H12C	0.9800
C3—N1—N2	106.63 (11)	C7—C6—C11	121.39 (13)
C1—N2—N1	113.29 (12)	C5—C6—C11	120.92 (12)
C1—N2—H2A	123.4	C8—C7—C6	122.40 (13)
N1—N2—H2A	123.4	C8—C7—H7A	118.8
N4—N3—C2	115.29 (12)	C6—C7—H7A	118.8
N3—N4—C5	122.19 (12)	C7—C8—C9	118.22 (13)
N3—N4—H4D	118.9	C7—C8—C12	120.53 (13)
C5—N4—H4D	118.9	C9—C8—C12	121.24 (13)
O1—C1—N2	128.34 (13)	C10—C9—C8	121.07 (13)
O1—C1—C2	127.52 (12)	C10—C9—H9A	119.5
N2—C1—C2	104.13 (12)	C8—C9—H9A	119.5
N3—C2—C3	127.04 (13)	C9—C10—C5	119.43 (13)
N3—C2—C1	127.81 (12)	C9—C10—H10A	120.3
C3—C2—C1	105.13 (12)	C5—C10—H10A	120.3
N1—C3—C2	110.81 (12)	C6—C11—H11A	109.5
N1—C3—C4	122.32 (13)	C6—C11—H11B	109.5
C2—C3—C4	126.86 (13)	H11A—C11—H11B	109.5
C3—C4—H4A	109.5	C6—C11—H11C	109.5
C3—C4—H4B	109.5	H11A—C11—H11C	109.5
H4A—C4—H4B	109.5	H11B—C11—H11C	109.5
C3—C4—H4C	109.5	C8—C12—H12A	109.5
H4A—C4—H4C	109.5	C8—C12—H12B	109.5
H4B—C4—H4C	109.5	H12A—C12—H12B	109.5
C10—C5—C6	121.18 (13)	C8—C12—H12C	109.5
C10—C5—N4	121.68 (13)	H12A—C12—H12C	109.5
C6—C5—N4	117.14 (12)	H12B—C12—H12C	109.5
C7—C6—C5	117.68 (13)
C3—N1—N2—C1	−0.01 (15)	N3—N4—C5—C10	−7.1 (2)
C2—N3—N4—C5	179.75 (12)	N3—N4—C5—C6	172.99 (12)
N1—N2—C1—O1	179.22 (13)	C10—C5—C6—C7	−1.3 (2)
N1—N2—C1—C2	−0.17 (15)	N4—C5—C6—C7	178.63 (11)
N4—N3—C2—C3	177.63 (12)	C10—C5—C6—C11	177.61 (12)
N4—N3—C2—C1	−0.2 (2)	N4—C5—C6—C11	−2.45 (19)
O1—C1—C2—N3	−0.9 (2)	C5—C6—C7—C8	1.0 (2)
N2—C1—C2—N3	178.50 (13)	C11—C6—C7—C8	−177.90 (12)
O1—C1—C2—C3	−179.13 (13)	C6—C7—C8—C9	0.2 (2)
N2—C1—C2—C3	0.28 (14)	C6—C7—C8—C12	179.27 (12)
N2—N1—C3—C2	0.20 (15)	C7—C8—C9—C10	−1.1 (2)
N2—N1—C3—C4	−178.85 (12)	C12—C8—C9—C10	179.80 (13)
N3—C2—C3—N1	−178.55 (13)	C8—C9—C10—C5	0.8 (2)
C1—C2—C3—N1	−0.30 (15)	C6—C5—C10—C9	0.4 (2)
N3—C2—C3—C4	0.5 (2)	N4—C5—C10—C9	−179.51 (12)
C1—C2—C3—C4	178.70 (13)

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
N2—H2A···O1i	0.88	1.95	2.8233 (15)	172
N4—H4D···O1	0.88	2.00	2.7286 (15)	139

Symmetry code: (i) −x, −y+1, −z+2.