1-[3-(4-Chloro­phen­yl)-5-(4-meth­oxy­phen­yl)-4,5-dihydro-1H-pyrazol-1-yl]butan-1-one

Hoong-Kun Fun; Ching Kheng Quah; S Samshuddin; B Narayana; B K Sarojini

doi:10.1107/S1600536812009105

. 2012 Mar 7;68(Pt 4):o975. doi: 10.1107/S1600536812009105

1-[3-(4-Chlorophenyl)-5-(4-methoxyphenyl)-4,5-dihydro-1H-pyrazol-1-yl]butan-1-one

Hoong-Kun Fun ^a,^*,^‡, Ching Kheng Quah ^a,^§, S Samshuddin ^b, B Narayana ^b, B K Sarojini ^c

PMCID: PMC3343949 PMID: 22590030

Abstract

In the title compound, C₂₀H₂₁ClN₂O₂, the benzene rings form dihedral angles of 6.35 (5) and 81.82 (5)° with the mean plane of the 4,5-dihydro-1H-pyrazole ring (r.m.s. deviation = 0.145 Å). This latter ring adopts an envelope conformation with the CH grouping as the flap. The dihedral angle between the benzene rings is 75.63 (4)°. In the crystal, molecules are linked by C—H⋯Cl and C—H⋯O hydrogen bonds into chains along [-201]. The crystal structure also features C—H⋯π interactions.

Related literature

For a related structure, see: Fun et al. (2010 ▶). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986 ▶). For standard bond lengths, see: Allen et al. (1987 ▶).

Experimental

Crystal data

C₂₀H₂₁ClN₂O₂
M _r = 356.84
Triclinic,
a = 6.7918 (3) Å
b = 10.8822 (4) Å
c = 13.2576 (5) Å
α = 109.202 (1)°
β = 91.396 (1)°
γ = 105.087 (1)°
V = 886.93 (6) Å³
Z = 2
Mo Kα radiation
μ = 0.23 mm⁻¹
T = 100 K
0.43 × 0.17 × 0.14 mm

Data collection

Bruker SMART APEXII DUO CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.908, T _max = 0.968
17324 measured reflections
6403 independent reflections
5492 reflections with I > 2σ(I)
R _int = 0.021

Refinement

R[F ² > 2σ(F ²)] = 0.035
wR(F ²) = 0.104
S = 1.04
6403 reflections
228 parameters
H-atom parameters constrained
Δρ_max = 0.43 e Å⁻³
Δρ_min = −0.30 e Å⁻³

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

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812009105/hb6658sup1.cif

e-68-0o975-sup1.cif^{(27.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812009105/hb6658Isup2.hkl

e-68-0o975-Isup2.hkl^{(313.4KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812009105/hb6658Isup3.cml

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

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

Cg1 is the centroid of the C1–C6 benzene ring.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C11—H11A⋯Cl1ⁱ	0.93	2.73	3.4539 (10)	135
C14—H14A⋯O2ⁱⁱ	0.93	2.51	3.3253 (12)	147
C18—H18A⋯Cg1ⁱⁱⁱ	0.97	2.62	3.4514 (9)	144

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

Acknowledgments

The authors thank Universiti Sains Malaysia (USM) for the Research University Grant (No. 1001/PFIZIK/811160). BN thanks the UGC for financial assistance through an SAP and BSR one-time grant for the purchase of chemicals. SS thanks Mangalore University for the research facilities.

supplementary crystallographic information

Comment

In continuation of our work on the synthesis and sturctures of pyrazoline derivatives (Fun et al., 2010), the title compound (I) is prepared and its crystal structure is reported.

In the title molecule (Fig. 1), the two benzene rings (C1-C6 and C10-C15) form dihedral angles of 6.35 (5) and 81.82 (5)°, respectively, with the mean plane of 4,5-dihydro-1H-pyrazole ring (N1/N2/C7-C9, r.m.s. deviation = 0.145 Å). The dihedral angle between the two benzene rings is 75.63 (4)°. Bond lengths are comparable with a related structure (Fun et al., 2010).

In the crystal structure, Fig. 2, molecules are linked via C11–H11A···Cl1 and C14–H14A···O2 hydrogen bonds (Table 1) into chains along [-201]. The crystal structure is further consolidated by C18–H18A···Cg1ⁱⁱⁱ (Table 1) interactions, where Cg1 is the centroid of C1-C6 benzene ring.

Experimental

A mixture of (2E)-1-(4-chlorophenyl)-3-(4-methoxyphenyl)prop-2-en-1-one (2.72 g, 0.01 mol) and hydrazine hydrate (0.5 ml, 0.01 mol) in 25 ml butyric acid was refluxed for 8 h. The reaction mixture was cooled and poured into 50 ml ice-cold water. The precipitate was collected by filtration and purified by recrystallization from ethanol. Colourless blocks of (I) were grown from a DMF solution by slow evaporation and yield of the compound was 76% (m.p. : 369 K).