N-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-di­hydro-1H-pyrazol-4-yl)-2-phenyl­acetamide

Manpreet Kaur; Jerry P Jasinski; Brian J Anderson; H S Yathirajan; B Narayana

doi:10.1107/S1600536813029590

. 2013 Nov 6;69(Pt 12):o1726–o1727. doi: 10.1107/S1600536813029590

N-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2-phenylacetamide

Manpreet Kaur ^a, Jerry P Jasinski ^b,^*, Brian J Anderson ^b, H S Yathirajan ^a, B Narayana ^c

PMCID: PMC3885014 PMID: 24454189

Abstract

The title compound, C₁₉H₁₉N₃O₂, crystallizes with two independent molecules (A and B) in the asymmetric unit. In molecule A, the pyrazole ring adopts a slightly disordered half-chair conformation while in B it is planar [r.m.s. deviation = 0.0386 (15) Å]. The dihedral angle between the mean planes of the two phenyl rings is 56.2 (8) in A and 38.2 (3)° in B. The N-phenyl substituent on the pyrazole ring is twisted by 46.5 (2) in A and 58.6 (4)° in B while the extended phenyl ring is twisted by 82.2 (8) in A and 87.5 (9)° in B. The mean plane of the amide group forms an angle of 74.8 (3) in A and 67.7 (1)° in B with respect to the phenyl ring. In addition, the amide group is rotated by 51.4 (1) in A and 53.6 (2)° in B from the the mean plane of the pyrazole ring. In the crystal, the two molecules are linked via N—H⋯O hydrogen bonds, supported by weak C—H⋯O interactions, forming dimers enclosing an R ₂ ²(10) ring motif. The dimers are linked via C—H⋯O interactions, forming a three-dimensional structure.

Related literature

For the structural similarity of N-substituted 2-arylacetamides to the lateral chain of natural benzylpenicillin, see: Mijin et al. (2008 ▶). For the coordination abilities of amides, see: Wu et al. (2008 ▶, 2010 ▶). For the pharmaceutical, insecticidal and non-linear properties of pyrazoles, see: Chandrakantha et al. (2013 ▶); Cheng et al. (2008 ▶); Hatton et al. (1993 ▶); Liu et al. (2010 ▶). For related structures, see: Fun et al. (2011a ▶,b ▶, 2012 ▶); Butcher et al. (2013a ▶,b ▶). For puckering parameters, see Cremer & Pople (1975 ▶). For standard bond lengths, see: Allen et al. (1987 ▶). graphic file with name e-69-o1726-scheme1.jpg

Experimental

Crystal data

C₁₉H₁₉N₃O₂
M _r = 321.37
Triclinic,
a = 10.1258 (7) Å
b = 10.4671 (8) Å
c = 17.8888 (12) Å
α = 100.833 (6)°
β = 92.527 (5)°
γ = 116.812 (7)°
V = 1643.9 (2) Å³
Z = 4
Cu Kα radiation
μ = 0.69 mm⁻¹
T = 173 K
0.48 × 0.32 × 0.26 mm

Data collection

Agilent Xcalibur (Eos, Gemini) diffractometer
Absorption correction: multi-scan (CrysAlis PRO and CrysAlis RED; Agilent, 2012 ▶) T _min = 0.876, T _max = 1.000
10216 measured reflections
6333 independent reflections
5485 reflections with I > 2σ(I)
R _int = 0.037

Refinement

R[F ² > 2σ(F ²)] = 0.046
wR(F ²) = 0.130
S = 1.04
6333 reflections
438 parameters
H-atom parameters constrained
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.23 e Å⁻³

Data collection: CrysAlis PRO (Agilent, 2012 ▶); cell refinement: CrysAlis PRO; data reduction: CrysAlis RED (Agilent, 2012 ▶); program(s) used to solve structure: SUPERFLIP (Palatinus & Chapuis, 2007 ▶); program(s) used to refine structure: SHELXL2012 (Sheldrick, 2008 ▶); molecular graphics: OLEX2 (Dolomanov et al., 2009 ▶); software used to prepare material for publication: OLEX2.

Supplementary Material

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536813029590/hg5356sup1.cif

e-69-o1726-sup1.cif^{(40.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813029590/hg5356Isup2.hkl

e-69-o1726-Isup2.hkl^{(347KB, hkl)}

Click here for additional data file.^{(6.6KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813029590/hg5356Isup3.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
N1A—H1A⋯O2B	0.86	1.97	2.8292 (16)	173
C14A—H14A⋯O1A ⁱ	0.93	2.55	3.454 (2)	165
N1B—H1B⋯O2A	0.86	1.98	2.8115 (16)	163
C2B—H2BA⋯O1B ⁱⁱ	0.97	2.55	3.4239 (19)	150
C4B—H4B⋯O1B ⁱⁱ	0.93	2.72	3.487 (2)	141
C8B—H8B⋯O2A	0.93	2.57	3.404 (2)	150
C14B—H14B⋯O1A ⁱⁱⁱ	0.93	2.70	3.398 (2)	132

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

Acknowledgments

MK is grateful to CPEPA–UGC for the award of a JRF and thanks the University of Mysore for research facilities. JPJ acknowledges the NSF–MRI program (grant No. CHE-1039027) for funds to purchase the X-ray diffractometer.

supplementary crystallographic information

1. Comment

N-Substituted 2-arylacetamides are biologically active compounds because of their structural similarity to the lateral chain of natural benzylpenicillin (Mijin et al., 2008). Amides are also used as ligands due to their excellent coordination abilities (Wu et al., 2008, 2010). In a variety of biological heterocyclic compounds, N-pyrazole derivatives are of great interest because of their chemical and pharmaceutical properties (Cheng et al., 2008). Some of the N-pyrazole derivatives have been found to exhibit good insecticidal activities (Hatton et al., 1993), antifungal activities (Liu et al., 2010) and non-linear optical properties (Chandrakantha et al., 2013). Crystal structures of some related acetamide and pyrazole derivatives are : N-(4-Bromophenyl)-2-(naphthalen-1-yl) acetamide, N-(3,5-Dichlorophenyl)-2-(naphthalen-1-yl)acetamide, N-(1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)-2- [4-(methylsulfanyl)phenyl]acetamide, (Fun et al., 2011a,b, 2012), 2-(2,4-Dichlorophenyl)-N-(1,5-dimethyl-3-oxo-2- phenyl-2,3-dihydro-1H-pyrazol-4-yl)acetamide, 2-(2,6-dichloro phenyl)-N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol- 4-yl)acetamide (Butcher et al., 2013a,b) have been reported. In view of the importance of amide derivatives of pyrazoles, this paper reports the crystal structure of the title compound (I), C₁₉H₁₉N₃O₂.

The title compound, (I), crystallizes with two independent molecules in the asymmetric unit (A and B) (Fig. 1). In molecule A, the pyrazole ring adopts a slightly disordered half-chair conformation while in B it is planar. The dihedral angle between the mean planes of the two phenyl rings is 56.2 (8)° (A) and 38.2 (3)° (B). The N-phenyl substituent on the pyrazole ring is twisted by 46.5 (2)° (A) and 58.6 (4)° (B) while the extended phenyl ring is twisted by 82.2 (8)° (A) and 87.5 (9)° (B). The mean plane of the amide group forms an angle of 74.8 (3)° (A)(C2A/C1A/O1A/N1A), 67.7 (1)° (B)(C2B/C1B/O1B/N1B) with respect to that of the phenyl rings. In addition, the amide group is rotated by 51.4 (1)° (A), 53.6 (2)° (B) from the the mean plane of the pyrazole rings. Bond lengths are in normal ranges (Allen et al., 1987). N—H···O intermolecular hydrogen bonds supported by a weak C14A—H14A···O1A intermolecular interaction are observed which link the molecules into dimers forming R₂²(10) graph set motifs (Fig. 2). Also, additional weak C—H···O intermolecular interactions are also observed which interlink the dimers and influence the crystal packing.

2. Experimental

Phenylacetic acid (0.136 g, 1 mmol) and 4-aminoantipyrine (0.203 g, 1 mmol), 1-ethyl-3-(3-dimethylaminopropyl)-carbodiimide hydrochloride (1.0 g, 0.01 mol) and were dissolved in dichloromethane (20 mL). The mixture was stirred in presence of triethylamine at 273 K for about 3 h. The contents were poured into 100 ml of ice-cold aqueous hydrochloric acid with stirring, which was extracted thrice with dichloromethane. Organic layer was washed with saturated NaHCO₃ solution and brine solution, dried and concentrated under reduced pressure to give the title compound (I). Single crystals were grown from methanol and acetone mixture (1:1) and further recrystallised from ethanol by by the slow evaporation method which were used as such for X-ray studies (M.P.: 445-447 K).