(E)-3-(4-Meth­oxy­phen­yl)-3-[3-(4-meth­oxy­phen­yl)-1H-pyrazol-1-yl]prop-2-enal

V Susindran; S Athimoolam; S Asath Bahadur; R Manikannan; S Muthusubramanian

doi:10.1107/S1600536813007678

. 2013 Mar 28;69(Pt 4):o594–o595. doi: 10.1107/S1600536813007678

(E)-3-(4-Methoxyphenyl)-3-[3-(4-methoxyphenyl)-1H-pyrazol-1-yl]prop-2-enal

V Susindran ^a, S Athimoolam ^b,^*, S Asath Bahadur ^c, R Manikannan ^d, S Muthusubramanian ^e

PMCID: PMC3629636 PMID: 23634123

Abstract

In the title molecule, C₂₀H₁₈N₂O₃, the pyrazole ring forms a dihedral angle of 2.2 (1)° with its methoxyphenyl substituent and a dihedral angle of 67.2 (1)° with the benzene substituent on the propenal unit. In the crystal, molecules are connected by weak C—H⋯O hydrogen bonds, forming R ₂ ²(26) and R ₂ ²(28) cyclic dimers that lie about crystallographic inversion centres. These dimers are further linked through C—H⋯O and C—H⋯N hydrogen bonds, forming C(8), C(9), C(10) and C(16) chain motifs. These primary motifs are further linked to form secondary C ₂ ²(15) chains and R ₂ ²(18) rings.

Related literature

For the pharmacological and medicinal properties of pyrazole compounds, see: Baraldi et al. (1998 ▶); Bruno et al. (1990 ▶); Chen & Li (1998 ▶); Cottineau et al. (2002 ▶); Londershausen (1996 ▶); Mishra et al. (1998 ▶); Smith et al. (2001 ▶). For related structures, see: Susindran et al. (2010a ▶,b ▶, 2012 ▶). For hydrogen-bond motifs, see: Etter et al. (1990 ▶).

Experimental

Crystal data

C₂₀H₁₈N₂O₃
M _r = 334.36
Triclinic,
a = 8.8081 (6) Å
b = 9.8474 (5) Å
c = 10.3292 (8) Å
α = 94.997 (12)°
β = 93.811 (14)°
γ = 106.719 (13)°
V = 850.85 (10) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.22 × 0.19 × 0.15 mm

Data collection

Bruker SMART APEX CCD diffractometer
8253 measured reflections
2993 independent reflections
2677 reflections with I > 2σ(I)
R _int = 0.020

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.107
S = 1.04
2993 reflections
228 parameters
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.25 e Å⁻³

Data collection: SMART (Bruker, 2001 ▶); cell refinement: SAINT (Bruker, 2001 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Click here for additional data file.^{(25.5KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813007678/sj5307sup1.cif

e-69-0o594-sup1.cif^{(25.5KB, cif)}

Click here for additional data file.^{(143.9KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813007678/sj5307Isup2.hkl

e-69-0o594-Isup2.hkl^{(143.9KB, hkl)}

Click here for additional data file.^{(6.7KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813007678/sj5307Isup3.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
C5—H5⋯O3ⁱ	0.93	2.73	3.366 (2)	126
C18—H18C⋯N2ⁱ	0.96	2.74	3.627 (2)	155
C14—H14⋯O2ⁱⁱ	0.93	2.49	3.301 (2)	145
C33—H33⋯O1ⁱⁱⁱ	0.93	2.82	3.642 (2)	148
C37—H37B⋯O2^iv	0.96	2.75	3.688 (2)	166
C37—H37C⋯O1^v	0.96	2.76	3.650 (2)	155

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

Acknowledgments

VS and SAB sincerely thank the Vice Chancellor and Management of Kalasalingam University, Anand Nagar, Krishnan Koil, for their support and encouragement.

supplementary crystallographic information

Comment

Pyrazoles are classified as both aromatic ring compounds and heterocyclic compounds and are characterized by a 5-membered ring structure composed of three carbon atoms and two nitrogen atoms in adjacent positions in the unsubstituted parent compound. Being so composed and having pharmacological effects on humans, they are classified as alkaloids although they are rare in nature. Pyrazole and its derivatives have been successfully tested for their antifungal (Chen & Li, 1998), antihistaminic (Mishra et al.,1998), anti-inflammatory (Smith et al., 2001), antiarrhythmic and sedative (Bruno et al., 1990), hypoglycemic (Cottineau et al., 2002), antiviral (Baraldi et al., 1998) and pesticidal (Londershausen, 1996) activities. Based on the above specifics and also as part of our continuing work on pyrazole related compounds (Susindran et al., 2010a,b, 2012), we report here the structure of the title pyrazole derivative.

The molecular structure of the title compound is shown in Fig. 1. The phenyl rings of the methoxyphenyl groups and the plane of the pyrazole ring form dihedral angles of 2.2 (1)° (with the C31—C36 ring) and 67.2 (1)° (with the C12—C17 ring). The crystal packing is stabilized through weak intermolecular C—H···O and C—H···N interactions (Table 1). Molecules are connected around inversion centres of the unit cell making R₂²(26) and R₂²(28) ring motifs (Etter et al., 1990) through C33—H33···O1 and C37—H37B···O2 interactions, respectively. These pairs of dimeric rings are further connected in a head-to-tail fashion by C37—H37B···O2 and C33—H33···O1 contacts, Table 1, to generate sheets of dimers approximately parallel to (112). These contacts also generate C₂²(15) chains in the ab-plane, Fig 2.

Additional chains are generated in the crystal as follows. A C(8) chain forms along the a-axis through a C14—H14···O2 interaction (Fig. 3) while C5—H5···O3 and C18—H18C···N2 contacts generate C(9) and C(10) chains along b. A combination of these contacts also generate an R₂²(18) ring motif (Fig. 4). Finally a C(16) chain of molecules linked in a head to tail fashion forms along the bc diagonal through a C37—H37C···O1 contact, Fig 5.

Experimental

Phosphorous oxychloride (0.024 mole) was added dropwise over 5 to 10 minutes to a mixture of 1-(4-methoxyphenyl)-1-ethanone N-[(E)-1-(4-methoxyphenyl)ethylidene]hydrazone (0.003 mole) and 3 ml of dimethyl formamide cooled in ice to 0°C. The reaction mixture was then irradiated with microwaves for 30 sec. The progress of the reaction was monitored by TLC. After completion of the reaction, the reaction mixture was poured into crushed ice and extracted with dichloromethane. The organic layer was dried over anhydrous sodium sulfate. The products were separated by column chromatography using petroleum ether and ethyl acetate mixture (98/2 v/v) as eluent. The title compound was crystallized from dichloromethane.