Crystal structure of ethyl N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-di­hydro-1H-pyrazol-4-yl)carbamate

Muhammad Danish; Muhammad Nawaz Tahir; Uzma Anwar; Muhammad Asam Raza

doi:10.1107/S2056989015006106

. 2015 Mar 28;71(Pt 4):o267. doi: 10.1107/S2056989015006106

Crystal structure of ethyl N-(1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)carbamate

Muhammad Danish ^a, Muhammad Nawaz Tahir ^b,^*, Uzma Anwar ^a, Muhammad Asam Raza ^a

PMCID: PMC4438802 PMID: 26029449

Abstract

In the title compound, C₁₄H₁₇N₃O₃, the dihedral angle between the benzene ring and the five-membered dihydropyrazole ring is 52.26 (9)°. The ethyl ester group is approximately planar (r.m.s. deviation 0.0568 Å) and subtends an angle 67.73 (8)° to the pyrazole ring. In the crystal, molecules are linked by pairs of N—H⋯O hydrogen bonds, forming inversion dimers with an R ₂ ²(10) ring motif. Weaker C—H⋯O contacts link these dimers into a three-dimensional network of molecules stacked along the a-axis direction. Offset π–π stacking interactions between the benzene rings [centroid-to-centroid distance = 3.8832 (12) Å] further stabilize the crystal packing.

Keywords: crystal structure, dihydropyrazole, ethyl ester, carbamate, hydrogen bonding, π–π stacking interactions

Related literature

For related structures see: Li et al. (2013 ▸). graphic file with name e-71-0o267-scheme1.jpg

Experimental

Crystal data

C₁₄H₁₇N₃O₃
M _r = 275.30
Monoclinic,
a = 8.2100 (4) Å
b = 11.4137 (6) Å
c = 15.1594 (8) Å
β = 93.403 (3)°
V = 1418.03 (13) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 296 K
0.38 × 0.34 × 0.20 mm

Data collection

Bruker Kappa APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▸) T _min = 0.968, T _max = 0.983
11712 measured reflections
3098 independent reflections
2368 reflections with I > 2σ(I)
R _int = 0.022

Refinement

R[F ² > 2σ(F ²)] = 0.043
wR(F ²) = 0.127
S = 1.06
3098 reflections
185 parameters
H-atom parameters constrained
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: APEX2 (Bruker, 2007 ▸); cell refinement: SAINT (Bruker, 2007 ▸); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▸); program(s) used to refine structure: SHELXL2014/6 (Sheldrick, 2015 ▸); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012 ▸) and PLATON (Spek, 2009 ▸); software used to prepare material for publication: WinGX (Farrugia, 2012 ▸) and PLATON.

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S2056989015006106/sj5447sup1.cif

e-71-0o267-sup1.cif^{(23.6KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S2056989015006106/sj5447Isup2.hkl

e-71-0o267-Isup2.hkl^{(170.2KB, hkl)}

Click here for additional data file.^{(5.6KB, cml)}

Supporting information file. DOI: 10.1107/S2056989015006106/sj5447Isup3.cml

Click here for additional data file.^{(1.1MB, tif)}

. DOI: 10.1107/S2056989015006106/sj5447fig1.tif

View of the asymmetric unit of title compound with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are shown as small circles of arbitrary radii.

Click here for additional data file.^{(1.5MB, tif)}

a . DOI: 10.1107/S2056989015006106/sj5447fig2.tif

The crystal packing of (I), viewed along the a axis, with hydrogen bonds shown as dashed lines.

CCDC reference: 1056157

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

DHA	DH	HA	D A	DHA
N3H3AO1ⁱ	0.86	1.99	2.8223(17)	164
C10H10AO1ⁱⁱ	0.96	2.56	3.343(2)	139
C11H11BO2ⁱⁱⁱ	0.96	2.66	3.576(2)	161

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

Acknowledgments

The authors acknowledge the provision of funds for purchase of the diffractometer and encouragement by Dr Muhammad Akram Chaudhary, Vice Chancellor, University of Sargodha, Pakistan.

supplementary crystallographic information

S1. Comment

The title compound (I), (Fig. 1) has been synthesized to examine its DNA binding potential and anti-microbial activity. The crystal structures of two closely related compounds, methyl (1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H- pyrazol-4-yl)carbamate and methyl (1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-yl)methylcarbamate monohydrate have been reported previously (Li et al., 2013).

In (I), the C1—C6 benzene ring and dihydropyrazol-3-one system, O1/N1/N2/N3/C7—C9 are planar with r.m.s. deviations of 0.0037 and 0.0398 Å, respectively. The dihedral angle between the two systems is 53.64 (5)°. The ethyl ester group, C12/C13/C14/O2/O3, is also planar (r.m.s. deviation 0.0568 Å) and subtends an angle 67.73 (8)° to the pyrazole ring. In the crystal structure classical N3—H3A···O1 hydrogen bonds form inversion dimers (Table 1, Fig. 2) with R₂²(10) ring motifs. Weaker C10–H10A···O1 and C11–H11B···O2 contacts link these dimers into a three dimensional network of molecules stacked along the a axis direction. Offset π···π stacking interactions between the benzene rings with Cg2···Cg2ⁱ = 3.8832 (12) Å further stabilise the crystal packing (Cg2 is the centroid of the C1—C6 benzene ring; i = 2 - x, -y, 1 - z).

S2. Experimental

4-aminoantipyrene (2 g, 9.84 mmole) was dissolved in 50 ml dimethyl formamide and anhydrous potassium carbonate (0.68 g, 4.92 mmole) was added with continuous stirring over 50 minutes. Ethyl chloroformate (1.3 ml) was added drop-wise with stirring over three minutes at 323 K. TLC monitoring showed the reaction to be complete in almost 4 h. The reaction mixture was then cooled to room temperature and transferred to crushed ice leading to the formation of a precipitate. This was separated by filtration and recrystallized from aqueous ethanol to yield (I) as light yellow plates.

Melting point: 477–479 K.