(2Z)-3-(3-Bromo­anilino)-1-(5-hy­droxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)but-2-en-1-one

Abdullah M Asiri; Hassan M Faidallah; Seik Weng Ng; Edward R T Tiekink

doi:10.1107/S1600536812006939

. 2012 Feb 24;68(Pt 3):o813. doi: 10.1107/S1600536812006939

(2Z)-3-(3-Bromoanilino)-1-(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)but-2-en-1-one

Abdullah M Asiri ^a,^b,^‡, Hassan M Faidallah ^a, Seik Weng Ng ^c, Edward R T Tiekink ^c,^*

PMCID: PMC3297875 PMID: 22412678

Abstract

In the title compound, C₂₀H₁₈BrN₃O₂, the central carbonyl group forms amine-N—H⋯O and hydroxy-O—H⋯O hydrogen bonds, which lead to two fused S(6) rings. The N-bound phenyl ring is coplanar with the five-membered ring to which it is attached [dihedral angle = 5.22 (18)°], but the dihedral angle [33.87 (17)°] between the terminal phenyl and bromobenzene rings indicates an overall twist in the molecule. In the crystal packing, molecules assemble into dimeric aggregates via C—H⋯π interactions.

Related literature

For background to the synthesis, see: Gelin et al. (1983 ▶); Bendaas et al. (1999 ▶). For the structures of the 4-chloro and 4-methoxy derivatives, see: Asiri, Al-Youbi, Alamry et al. (2011 ▶); Asiri, Al-Youbi, Faidallah et al. (2011 ▶).

Experimental

Crystal data

C₂₀H₁₈BrN₃O₂
M _r = 412.28
Monoclinic,
a = 8.7065 (5) Å
b = 11.7982 (8) Å
c = 17.5954 (12) Å
β = 101.536 (6)°
V = 1770.9 (2) Å³
Z = 4
Mo Kα radiation
μ = 2.34 mm⁻¹
T = 100 K
0.25 × 0.10 × 0.05 mm

Data collection

Agilent SuperNova Dual diffractometer with an Atlas detector
Absorption correction: multi-scan (CrysAlis PRO; Agilent, 2011 ▶) T _min = 0.592, T _max = 0.892
7812 measured reflections
4041 independent reflections
3033 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.047
wR(F ²) = 0.105
S = 1.01
4041 reflections
245 parameters
2 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.58 e Å⁻³
Δρ_min = −0.47 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2011 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis PRO; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 (Farrugia, 1997 ▶) and DIAMOND (Brandenburg, 2006 ▶); software used to prepare material for publication: publCIF (Westrip, 2010 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812006939/sj5199sup1.cif

e-68-0o813-sup1.cif^{(19.8KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812006939/sj5199Isup2.hkl

e-68-0o813-Isup2.hkl^{(194KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812006939/sj5199Isup3.cml

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

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 is the centroid of the N1/N2/C7–C9 ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1⋯O2	0.84 (1)	1.68 (3)	2.468 (3)	154 (6)
N3—H3⋯O2	0.88 (1)	1.87 (3)	2.617 (4)	142 (4)
C14—H14B⋯Cg1ⁱ	0.98	2.69	3.495 (4)	140

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Symmetry code: (i) Inline graphic .

Acknowledgments

The authors are thankful to the Center of Excellence for Advanced Materials Research and the Chemistry Department of King Abdulaziz University for providing research facilities. We also thank the Ministry of Higher Education (Malaysia) for funding structural studies through the High-Impact Research scheme (UM.C/HIR/MOHE/SC/12).

supplementary crystallographic information

Comment

The title compound, 3-(3-bromoanilino)-1-(5-hydroxy-3-methyl-1-phenyl-1H-pyrazol-4-yl)but-2-en-1-one (I), was synthesized during investigations of reactions between pyrazoles and aniline derivatives based on literature precedents (Gelin et al., 1983; Bendaas et al., 1999) and was one of several compounds that were isolated in crystalline form (Asiri, Al-Youbi, Alamry et al., 2011; Asiri, Al-Youbi, Faidallah et al., 2011). As a continuation of these structural studies, the analysis of (I) is now described.

In (I), Fig. 1, The configuration about the formal C12═C13 bond [1.376 (4) Å] is Z. This arrangement allows the central O2-carbonyl atom to accept two hydrogen bonds from the adjacent hydroxyl and amine groups to close a pair of fused S(6) rings, Table 1. While the N-bound phenyl ring is co-planar with the five-membered ring to which it is connected, forming a dihedral angle of 5.22 (18)°, a twist in the molecule is evident as seen in the dihedral angle formed between the terminal phenyl and bromobenzene rings, dihedral angle = 33.87 (17)°.

The most notable feature of the crystal packing is the formation of C—H···π interactions where the π-system is the five-membered ring, Table 1. The resulting dimeric aggregates assemble into zigzag layers in the bc plane and stack along the a axis, Fig. 2.

Experimental

A solution of 4-acetoacetyl-5-hydroxy-3-methyl-1-phenylpyrazole (0.005 mol) and 3-bromo-aniline (0.005 mol) in ethanol (25 ml) was refluxed for 2 h. The precipitate obtained from the hot solution was collected washed with methanol and recrystallized from its ethanol-benzene solution to provide yellow crystals; M.pt: 412–413 K.