4-Benzyl-6-p-tolyl­pyridazin-3(2H)-one

Ahmad Oubair; Jean-Claude Daran; Rachid Fihi; Lhou Majidi; Mohamed Azrour

doi:10.1107/S1600536809018376

. 2009 May 20;65(Pt 6):o1350–o1351. doi: 10.1107/S1600536809018376

4-Benzyl-6-p-tolylpyridazin-3(2H)-one

Ahmad Oubair ^a, Jean-Claude Daran ^b, Rachid Fihi ^a, Lhou Majidi ^a, Mohamed Azrour ^c,^*

PMCID: PMC2969805 PMID: 21583202

Abstract

The title compound, C₁₈H₁₆N₂O, is a new dihydropyridazin-3(2H)-one derivative synthesized in one step by condensation of α-benzylidene-γ-tolylbutenolide with hydrazine. The molecule is not planar; the tolyl and pyridazine rings are twisted with respect to each other making a dihedral angle of 27.35 (9)° and the benzyl ring is nearly perpendicular to the pyridazine ring with a dihedral angle of 85.24 (5)°. In the crystal structure, inversion dimers arise, being linked by pairs of N—H⋯O hydrogen bonds. Weak C—H⋯O hydrogen bonds and weak offset π–π stacking stabilize the packing. The π–π stacking occurs between the pyridazine rings of symmetry-related molecules, with a centroid–centroid distance of 3.748 Å, an interplanar distance of 3.605 Å and a slippage of 1.024 Å.

Related literature

For related compounds displaying biological activities, see: Sayed et al. (2002 ▶); Frolov et al. (2004 ▶); Piaz et al. (1994 ▶); Coelho et al. (2004 ▶); Malinka et al. (2004 ▶); Ogretir et al. (2002 ▶); Okcelik et al. (2003 ▶); Sotelo et al. (2003 ▶); Youssef et al. (2005 ▶). For related structures, see: Cao et al. (2003 ▶); Daran et al. (2006 ▶); Fihi et al. (1995 ▶); Filler & Piasek (1973 ▶); Roussel et al. (2000 ▶, 2003 ▶). For graph-set theory, see: Bernstein et al. (1995 ▶). graphic file with name e-65-o1350-scheme1.jpg

Experimental

Crystal data

C₁₈H₁₆N₂O
M _r = 276.33
Monoclinic,
a = 7.2487 (4) Å
b = 10.4469 (5) Å
c = 19.1869 (9) Å
β = 99.598 (5)°
V = 1432.62 (12) Å³
Z = 4
Mo Kα radiation
μ = 0.08 mm⁻¹
T = 180 K
0.50 × 0.48 × 0.08 mm

Data collection

Oxford Diffraction Xcalibur diffractometer
Absorption correction: multi-scan (CrysAlis RED; Oxford Diffraction, 2006 ▶) T _min = 0.965, T _max = 0.993
10925 measured reflections
2914 independent reflections
1622 reflections with I > 2σ(I)
R _int = 0.044

Refinement

R[F ² > 2σ(F ²)] = 0.041
wR(F ²) = 0.121
S = 0.94
2914 reflections
190 parameters
H-atom parameters constrained
Δρ_max = 0.20 e Å⁻³
Δρ_min = −0.20 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2006 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2006 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SIR97 (Altomare et al., 1999 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEPIII (Burnett & Johnson, 1996 ▶), ORTEP-3 for Windows (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809018376/bg2256sup1.cif

e-65-o1350-sup1.cif^{(20.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809018376/bg2256Isup2.hkl

e-65-o1350-Isup2.hkl^{(140.1KB, hkl)}

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
N2—H2⋯O1ⁱ	0.88	1.89	2.7686 (19)	178
C34—H34⋯O1ⁱⁱ	0.95	2.57	3.512 (2)	169

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

supplementary crystallographic information

Comment

In recent years a number of 6-arylpyridazin-3(2H)-ones have been reported to possess antimicrobial (Sayed et al., 2002), anti-inflammatory (Frolov et al., 2004), herbicidal (Piaz et al.,1994), antiplatelet activities (Coelho et al., 2004), anticancer effects (Malinka et al., 2004), antifeedant (Cao et al., 2003), antihypertensive (Ogretir et al.,2002), potent analgesic (Okcelik et al., 2003) and other anticipated biological(Youssef et al., 2005) and pharmacological properties (Sotelo et al., 2003).

In previous papers treating the reactivity of lactones bearing an exocyclic carbon-carbon double bond with 1,3-dipoles (Fihi et al., 1995; Roussel et al., 2000, 2003; Daran et al., 2006), we reported that cycloaddition reactions lead to spiroheterocyclic compounds or evolutive products. In this paper, we describe the synthesis of a new dihydro-2 H– pyridazin-3-onederivative. The condensation ofα-benzylidene-γ-tolylbutenolide(1) and hydrazine (2) in reflux in toluene leads in one step to pyridazin-3-one(3). (Scheme).

Since the ¹H and ¹³CNMR studies did not provide unambiguous information, a single-crystal of (3) was subjected to X-ray diffraction analysis to determine the structure of the product.

The molecule is not planar, the tolyl and the pyridazin rings are twisted to each other making a dihedral angle of 27.35 (9)° and the phenyl ring is nearly perpendicular to the pyridazin ring with a dihedral angle of 85.24 (5)° (Fig. 1).

The molecules are connected two by two through N—H···O hydrogen bonds with a R₂²(8) graph set motif (Bernstein et al., 1995) then building a pseudo dimer arranged around the inversion center (Fig. 1, Table 1). Weak C—H···O hydrogen bonds and weak offset π-π stacking stabilize the packing. The π-π stacking occurs between the pyridazin rings of symmetry related molecules with centroid-to-centroid distance of 3.748 Å and interplanar distance of 3.605Å and a slippage of 1.024 Å.

Experimental

α-benzylidene-γ-tolylbutenolide (1) was synthesized according to the literature procedure (Filler & Piasek, 1973). (0.036 g, 1.125 mmol) of hydrazine was added to a solution of (1) (0.2 g, 0.76 mmol) in toluene (25 ml) and the mixture was stirred at reflux for 24 h. The solvent was then evaporated under reduced pressure. The residue was recrystallized from ethanol, and purified by chromatography on silica gel (eluant: ethyl acetate / hexane: 20 / 80). The pyridazinone was recrystallized from ethanol.