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

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

doi:10.1107/S1600536812017849

. 2012 Apr 28;68(Pt 5):o1554. doi: 10.1107/S1600536812017849

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

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

PMCID: PMC3344653 PMID: 22590415

Abstract

In the title compound, C₂₆H₂₇BrN₃O₃P, the central pyrazole ring forms a dihedral angle of 71.7 (2)° with the bromophenyl 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. Four C atoms of the 3-phenyl ring are disordered over two sets of sites [site occupancies = 0.745 (6) and 0.225 (6)].

Related literature

For information on pyrazole derivatives, see: Sullivan et al. (2006 ▶); Patel et al. (2010 ▶). For a related structure, see: Saeed et al. (2009 ▶).

Experimental

Crystal data

C₂₆H₂₇BrN₃O₃P
M _r = 540.39
Monoclinic,
a = 11.2553 (6) Å
b = 23.9104 (15) Å
c = 9.4741 (5) Å
β = 91.229 (3)°
V = 2549.1 (2) Å³
Z = 4
Mo Kα radiation
μ = 1.71 mm⁻¹
T = 293 K
0.25 × 0.22 × 0.19 mm

Data collection

Bruker APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ▶) T _min = 0.953, T _max = 0.964
35555 measured reflections
4502 independent reflections
3093 reflections with I > 2σ(I)
R _int = 0.065

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.129
S = 1.09
4502 reflections
346 parameters
H-atom parameters constrained
Δρ_max = 0.63 e Å⁻³
Δρ_min = −0.34 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); 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 for Windows (Farrugia, 1997 ▶); software used to prepare material for publication: PLATON (Spek, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812017849/bt5876sup1.cif

e-68-o1554-sup1.cif^{(26.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812017849/bt5876Isup2.hkl

e-68-o1554-Isup2.hkl^{(216.1KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812017849/bt5876Isup3.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
N1—H1⋯O1ⁱ	0.86	2.48	3.305 (4)	162

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Symmetry code: (i) Inline graphic .

Acknowledgments

SA thanks the UGC, India, for financial support.

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 crystal structure determination of the title compound was carried out and the results are presented here.

X-Ray analysis confirms the molecular structure and atom connectivity as 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 central pyrazole ring and the bromophenyl ring are almost perpendicular with the dihedral angle of 71.7 (2) °, whereas the two phenyl rings are twisted from the pyrazole ring as can be seen from the dihedral angle of 15.0 (1)° and 39.3 (3)°, respectively. The pyrazole ring system is essentially planar, with maximum deviation of 0.006 (4) for atom C14. The sum of bond angles around N2[359.7 (3) °] of the pyrazole ring is in accordance with sp³ hybridization. The atoms Br1 and N1 are deviated by -0.039 (1) Å and 0.019 (3) Å from the leastsquares plane of the benzene(C1—C6) ring. The four carbon atoms in the phenyl ring are disordered over two sets of sites [site occupancies = 0.745 (6) and 0.225 (6)].

The phosphinite group assumes an extended conformation as can be seen from torsion angles P1—O2—C8—C9 of -179.0 (5)°. A pair of N1—H1···O1 hydrogen bonds at x,y,z and -x,1 - y,2 - z form a cyclic centrosymmetric dimer [R²₂(10)]. These hdrogen bonds are crosslinked to Br1 to form S(5) ring (C1—C6—N1—H1—Br1) motif. The crystal packing is stabilized N—H···O hydrogen bonds.

Experimental

A mixture of 1,3-diphenyl-1H-pyrazole-4-carbaldehyde (1 mmol), 2-bromoaniline (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.