2-(3-Oxo-1,3-dihydro­isobenzofuran-1-yl)­phthalazin-1(2H)-one

You-Lei Zhang; Yu-Jun Wu; Guo Peng; Hong Deng

doi:10.1107/S1600536809011970

. 2009 Apr 8;65(Pt 5):o974. doi: 10.1107/S1600536809011970

2-(3-Oxo-1,3-dihydroisobenzofuran-1-yl)phthalazin-1(2H)-one

You-Lei Zhang ^a, Yu-Jun Wu ^a, Guo Peng ^a, Hong Deng ^a,^*

PMCID: PMC2977671 PMID: 21584014

Abstract

The reaction of 2-carboxybenzaldehyde and hydrazine hydrate unexpectedly yielded the title compound, C₁₆H₁₀N₂O₃, which comprises one phthalide ring, one phthalazine system and a chiral centre. The phthalide unit is almost perpendicular to the phthalazine system, forming a dihedral angle of 87.1 (3)°. The packing is governed by weak C—H⋯O hydrogen-bonding interactions, forming layers parallel to the ab plane.

Related literature

For general background to non-covalent interactions, see: Bernstein et al. (1995 ▶); Roesky & Andruh (2003 ▶). For related compounds, see: Nelson et al. (1982 ▶); Li et al. (2002 ▶); Özbey et al. (1998 ▶).

Experimental

Crystal data

C₁₆H₁₀N₂O₃
M _r = 278.26
Triclinic,
a = 7.2356 (2) Å
b = 8.0369 (2) Å
c = 11.1686 (4) Å
α = 80.047 (2)°
β = 86.093 (2)°
γ = 88.6550 (10)°
V = 638.17 (3) Å³
Z = 2
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 296 K
0.20 × 0.18 × 0.15 mm

Data collection

Bruker APEXII area-detector diffractometer
Absorption correction: none
6746 measured reflections
2295 independent reflections
1626 reflections with I > 2σ(I)
R _int = 0.030

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.110
S = 1.02
2295 reflections
190 parameters
H-atom parameters constrained
Δρ_max = 0.14 e Å⁻³
Δρ_min = −0.17 e Å⁻³

Data collection: APEX2 (Bruker, 2004 ▶); cell refinement: SAINT (Bruker, 2004 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: XP in SHELXTL (Sheldrick, 2008 ▶); software used to prepare material for publication: SHELXL97.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809011970/rz2283sup1.cif

e-65-0o974-sup1.cif^{(16KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536809011970/rz2283Isup2.hkl

e-65-0o974-Isup2.hkl^{(112.8KB, 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
C16—H16⋯O3ⁱ	0.93	2.41	3.2935 (19)	158
C4—H4⋯O1ⁱⁱ	0.93	2.54	3.215 (2)	130

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

Acknowledgments

The authors acknowledge South China Normal University for supporting this work.

supplementary crystallographic information

Comment

Hydrogen bonding as an important type of non-covalent interaction plays a great role in supramolecular chemistry and material sciences (Bernstein et al., 1995). Hydrogen bonding between solvent molecules and heterocycle compounds containing O or N donors has been confirmed to be a useful and powerful organizing force to form supramolecules (Roesky & Andruh, 2003). It has been reported (Nelson et al., 1982) that the reaction of 2,6-diacetylpyridine and 1,2-phenylenediamine can form benzimidazole groups via oxidative dehydrogenation. Recently, in the reaction of 5-bromo-2-hydroxybenzaldehyde and 1,2-phenylenediamine in the presence of anhydrous ethanol solution a benzimidazole derivate have also been isolated (Li et al., 2002). In this paper, we chose 2-carboxybenzaldehyde and hydrazinehydrate as reagents and unexpectedly isolated the heterocyclic title compound.

The molecular structure of the title compound is shown in Fig. 1. The phthalazine system is almost planar with the N1—C9—C10—C11 and C14—C15—C16—N2 torsion angles of -175.9 (2) and 178.0 (2)°, respectively. The phthalide ring system is also almost planar, the O2—C8—C6—C5 torsion angle being -176.7 (2)°. The C8—N1 bond length (1.449 (2) Å) indicates single bond character, and the corresponding bond angles demonstrate the sp³ character of the C8 atom (chiral centre). The C16—N2 bond length (1.287 (2) Å) in the phthalazine ring has double bond character and is shorter than that found in the azomethine group of a related compound (Özbey et al., 1998). The phthalide ring system is almost perpendicular to the phthalazine ring system, the dihedral angle they form being 87.1 (3)°. In the crystal structure, the molecules are linked via weak C—H···O hydrogen bonding interactions forming layers parallel to the ab plane (Table 1, Fig. 2).

Experimental

2-Carboxybenzaldehyde (0.30 g, 2 mmol) and hydrazinehydrate (0.050 g, 1 mmol) were added to methanol (20 ml), and the mixture was refluxed for 3 h at 80°C. The resulting yellow precipitate was filtered and recrystallized from a MeOH/DMSO (5:1 v/v) solution. Colourless lamellar crystals were obtained on slow evaporation of the solvents at room temperature.