1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-aminium bromide monohydrate

Yan-Yun Yang; Liang Xu; Ting-Guo Kang; Ting Chen; Ping Wu

doi:10.1107/S1600536812023550

. 2012 May 31;68(Pt 6):o1964. doi: 10.1107/S1600536812023550

1,5-Dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-aminium bromide monohydrate

Yan-Yun Yang ^a, Liang Xu ^a,^*, Ting-Guo Kang ^a, Ting Chen ^a, Ping Wu ^a

PMCID: PMC3379513 PMID: 22719711

Abstract

In the title hydrated molecular salt, C₁₁H₁₄N₃O⁺·Br⁻·H₂O, the Br⁻ anion is split and appears as two independent half-occupied Br⁻ anions on twofold rotation axes. The dihedral angle between the phenyl ring and the mean plane of the 2,3-dihydro-1H-pyrazole ring (r.m.s. devation = 0.014 Å) is 62.43 (7)°. In the crystal, the components are connected via O—H⋯Br and N—H⋯O hydrogen bonds to form a one-dimensional polymeric structure propagating along [001].

Related literature

For general background on pyrazolone derivatives, see: Casas et al. (2007 ▶); Jain et al. (2003 ▶); Zhang et al. (2008 ▶). For related structures, see: Chitradevi et al. (2009 ▶); Murtaza et al.(2011 ▶). For bond-length data, see: Allen et al. (1987 ▶). graphic file with name e-68-o1964-scheme1.jpg

Experimental

Crystal data

C₁₁H₁₄N₃O⁺·Br⁻·H₂O
M _r = 302.17
Monoclinic,
a = 14.9080 (19) Å
b = 15.3961 (19) Å
c = 11.1501 (14) Å
β = 93.657 (2)°
V = 2554.0 (6) Å³
Z = 8
Mo Kα radiation
μ = 3.21 mm⁻¹
T = 296 K
0.22 × 0.20 × 0.18 mm

Data collection

Bruker SMART CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.489, T _max = 0.556
11995 measured reflections
3222 independent reflections
2081 reflections with I > 2σ(I)
R _int = 0.044

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.108
S = 1.04
3222 reflections
155 parameters
H-atom parameters constrained
Δρ_max = 0.48 e Å⁻³
Δρ_min = −0.40 e Å⁻³

Data collection: SMART (Bruker, 1998 ▶); cell refinement: SAINT (Bruker, 1998 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXTL.

Supplementary Material

Crystal structure: contains datablock(s) I, global. DOI: 10.1107/S1600536812023550/su2432sup1.cif

e-68-o1964-sup1.cif^{(17.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812023550/su2432Isup2.hkl

e-68-o1964-Isup2.hkl^{(157.4KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812023550/su2432Isup3.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
O1W—H1WA⋯Br1	0.85	2.51	3.360 (2)	173
O1W—H1WB⋯Br2	0.85	2.52	3.371 (3)	173
N3—H3B⋯O1ⁱ	0.89	1.89	2.692 (3)	150
N3—H3C⋯O1W	0.89	2.55	3.321 (3)	146
N3—H3C⋯O1ⁱⁱ	0.89	2.37	3.004 (3)	129
N3—H3D⋯O1Wⁱⁱ	0.89	1.99	2.817 (4)	153

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

Acknowledgments

The authors thank Liaoning University of Traditional Chinese Medicine for supporting this study (grant No. YXRC0920).

supplementary crystallographic information

Comment

4-Aminoantipyrene, which contains a pyrazolone ring, is an important compound in the class of analgesic agents used in otic solutions in combination with other analgesics such as benzocaine and phenylephrine (Jain et al., 2003). Pyrazolone is a five-membered lactam ring compound containing two N atoms and a ketone in the same molecule. Such pyrazolone derivatives form a very important class of heterocycles due to their properties and applications (Casas et al., 2007; Zhang et al., 2008). We report herein on the synthesis and crystal structure of the title compound.

The asymmetric unit of title compound, Fig. 1, consists of three components: a 1,5-dimethyl-3-oxo-2-phenyl-2,3-dihydro-1H-pyrazol-4-aminium cation, a bromide ion and a water molecule. The Br anion is split and appears as two independent half-occupied Br anions, Br1 and Br2, on two-fold rotation axes. In cation, the phenyl ring A (C1–C6) and the 2,3-dihydro-1H-pyrazole ring B (N1/N2/C7/C8/C11) are planar with r.m.s. deviations of 0.019 and 0.014 Å. The dihedral angle between A/B is 62.43 (7)°. The attached atoms O1, N3, C9 and C10 are at a distance of 0.030 (3), 0.053 (3), 0.130 (3) and 0.140 (3) Å respectively, from the mean plane of B. The bond lengths (Allen et al., 1987) and angles are within normal ranges. The crystal structure of some similar compounds have been reported (Chitradevi et al., 2009; Murtaza et al., 2011).

In the crystal, the various components are connected by N—H···O and O—H···Br hydrogen bonds (Table 1 and Fig. 2) to form an infinite one-dimensional arrangement parallel to [001].

Experimental

4-Aminoantipyrine (0.203 g, 1.0 mmol) and dibromomethane (0.173 g, 1.0 mmol) were dissolved in water (15 ml). The mixture was refluxed for 3 h and then the solvent was evaporated on rotary evaporator to almost dryness. The crude product was recrystallized from water yielding block-like yellow crystals of the title compound.