Diethyl [(2-chloro­anilino)(1,3-diphenyl-1H-pyrazol-4-yl)meth­yl]phospho­nate

G Suresh; A Nandakumar; V Sabari; P T Perumal; S Aravindhan

doi:10.1107/S1600536812051719

. 2013 Jan 4;69(Pt 2):o182. doi: 10.1107/S1600536812051719

Diethyl [(2-chloroanilino)(1,3-diphenyl-1H-pyrazol-4-yl)methyl]phosphonate

G Suresh ^a, A Nandakumar ^b, V Sabari ^a, P T Perumal ^b, S Aravindhan ^a,^*

PMCID: PMC3569244 PMID: 23424467

Abstract

In the title compound, C₂₆H₂₇ClN₃O₃P, the mean plane of the central pyrazole ring forms a dihedral angle of 71.37 (14)° with the chlorophenyl ring. In the crystal, molecules are linked by pairs of N—H⋯O hydrogen bonds, forming inversion dimers with R ² ₂(10) ring motifs. The 3-phenyl ring is disordered with four C atoms occupying two sets of sites with an occupancy ratio of 0.748 (4):0.252 (4).

Related literature

For information on pyrazole derivatives, see: Sullivan et al. (2006 ▶); Patel et al. (2010 ▶). For related structures, see: Saeed et al. (2009 ▶); Suresh et al. (2012 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₆H₂₇ClN₃O₃P
M _r = 495.93
Monoclinic,
a = 11.2379 (3) Å
b = 23.7075 (6) Å
c = 9.4570 (2) Å
β = 90.809 (1)°
V = 2519.31 (11) Å³
Z = 4
Mo Kα radiation
μ = 0.25 mm⁻¹
T = 298 K
0.25 × 0.20 × 0.18 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T _min = 0.941, T _max = 0.957
14995 measured reflections
4289 independent reflections
3322 reflections with I > 2σ(I)
R _int = 0.020

Refinement

R[F ² > 2σ(F ²)] = 0.045
wR(F ²) = 0.135
S = 1.05
4289 reflections
346 parameters
99 restraints
H-atom parameters constrained
Δρ_max = 0.35 e Å⁻³
Δρ_min = −0.29 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 2012 ▶); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▶).

Supplementary Material

Click here for additional data file.^{(26.9KB, cif)}

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812051719/su2545sup1.cif

e-69-0o182-sup1.cif^{(26.9KB, cif)}

Click here for additional data file.^{(205.9KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812051719/su2545Isup2.hkl

e-69-0o182-Isup2.hkl^{(205.9KB, hkl)}

Click here for additional data file.^{(9KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536812051719/su2545Isup3.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
N3—H3A⋯O1ⁱ	0.86	2.37	3.199 (3)	163

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Symmetry code: (i) Inline graphic .

Acknowledgments

GS and SA thank the UGC, India, for financial support. GS thanks the SAIF, IIT-Madras, for the instrumentation facility.

supplementary crystallographic information

Comment

Pyrazoles exhibit a variety of pharmacological properties for e.g antibacterial and anti-inflammatory activities (Sullivan et al., 2006; Patel et al., 2010). In view of their importance, the title compound was synthesized and we report herein on its crystal structure.

The molecular structure of the title molecule is illustrated in Fig. 1. The bond lengths N2—C13 and N3—C14 are normal and comparable to the corresponding values observed in the related structure of 3-(3-Chloroanilino)-1-(3,5-dimethyl-1H-pyrazol-1-yl)propan-1-one (Saeed et al., 2009). The pyrazole ring system is essentially planar, with a maximum deviation of -0.003 (2) Å for atom N2. The mean plane of the pyrazole ring and the chlorophenyl ring (C17-C22) are almost perpendicular to one another with a dihedral angle of 71.37 (14) °, whereas the two phenyl rings (C4-C9) and the major component of ring (C10-C15) are twisted out of the plane of the pyrazole ring, as can be seen from the dihedral angles of 15.84 (14)° and 39.2 (2)°, respectively.

The sum of the bond angles around atom N2 [359.75 (2)°] of the pyrazole ring is in accordance with sp³ hybridization. Atoms Cl1 and N3 deviate by -0.0278 (9) Å and 0.0206 (21) Å from the mean plane of the benzene (C17—C22) ring. The four carbon atoms in the phenyl ring (C10-C16) are disordered over two sets of sites [site occupancies = 0.748 (4) and 0.252 (4)]. The phosphinite group assumes an extended conformation as can be seen from the torsion angles P1—O2—C23—C24 of 179.2 (3)° and P1—O3—C25—C26 of 131.2 (2)°. They are close to those observed in a similar structure (Suresh et al., 2012).

In the crystal, a pair of N—H···O hydrogen bonds link molecules to form inversion dimers, with an R²₂(10) ring motif (Bernstein et al., 1995), that stack along the c axis (Fig. 2 and Table 1).

Experimental

A mixture of 1,3-diphenyl-1H-pyrazole-4-carbaldehyde (1 mmol), 2-chloroaniline (1 mmol), diethyl phosphite (1.5 mmol), and pottasium hydrogen sulfate (20 mol%) under neat condition was stirred at room temperature. After completion of the reaction as indicated by TLC, it was poured into water and extracted with ethyl acetate. The organic layer was dried over sodium sulfate and concentrated under vacuum. The crude product was chromatographed using an ethyl acetate/petroleum ether (30:70) mixture. Crystals suitable for X-ray diffraction were obtained by slow evaporation of a solution of the title compound in ethyl acetate at room temperature.