2-Benzyl-5-meth­oxy­isoindoline-1,3-dione

Noemi Vila; María Carmen Costas-Lago; Pedro Besada; Carmen Terán

doi:10.1107/S160053681302638X

. 2013 Sep 28;69(Pt 10):o1594–o1595. doi: 10.1107/S160053681302638X

2-Benzyl-5-methoxyisoindoline-1,3-dione

Noemi Vila ^a, María Carmen Costas-Lago ^a, Pedro Besada ^a, Carmen Terán ^a,^*

PMCID: PMC3790449 PMID: 24098268

Abstract

The title N-benzylphthalimide derivative, C₁₆H₁₃NO₃, consists of two planar moieties, viz. the phthalimide system (r.m.s. deviation = 0.007 Å) and the phenyl ring, which make a dihedral angle of 84.7 (6)°. The methoxy group is almost coplanar with the phathalimide ring, as shown by the C—C—O—C torsion angle of −171.5 (2)°. In the crystal, the molecules are self-assembled via non-classical C—H⋯O hydrogen bonds, forming a tape motif along [110].

Related literature

For background to the applications of phthalimide derivatives, see: Luzzio (2005 ▶); Barooah & Baruah (2007 ▶); Sharma et al. (2010 ▶); Warzecha et al. (2006 ▶). For different approaches to synthesize N-benzylphthalimides, see: Luzzio (2005 ▶); Cao & Alper (2010 ▶); Vidal et al. (2000 ▶). For the synthesis of the title compound, see: Favor et al. (2008 ▶); Haj-Yehia & Khan (2004 ▶). For related structures, see: Warzecha et al. (2006a ▶,b ▶,c ▶); Jiang et al. (2008 ▶). graphic file with name e-69-o1594-scheme1.jpg

Experimental

Crystal data

C₁₆H₁₃NO₃
M _r = 267.27
Monoclinic,
a = 8.476 (4) Å
b = 5.264 (3) Å
c = 28.295 (13) Å
β = 93.589 (9)°
V = 1260.0 (11) Å³
Z = 4
Mo Kα radiation
μ = 0.10 mm⁻¹
T = 100 K
0.49 × 0.13 × 0.07 mm

Data collection

Bruker SMART 1000 CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.954, T _max = 0.993
5768 measured reflections
2204 independent reflections
1433 reflections with I > 2σ(I)
R _int = 0.083

Refinement

R[F ² > 2σ(F ²)] = 0.053
wR(F ²) = 0.137
S = 1.00
2204 reflections
183 parameters
H-atom parameters constrained
Δρ_max = 0.30 e Å⁻³
Δρ_min = −0.27 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: PLATON (Spek, 2009 ▶) and Mercury (Macrae et al., 2006 ▶); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▶).

Supplementary Material

Crystal structure: contains datablock(s) I, New_Global_Publ_Block. DOI: 10.1107/S160053681302638X/fy2100sup1.cif

e-69-o1594-sup1.cif^{(23.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S160053681302638X/fy2100Isup2.hkl

e-69-o1594-Isup2.hkl^{(108.4KB, hkl)}

Click here for additional data file.^{(5.2KB, cml)}

Supplementary material file. DOI: 10.1107/S160053681302638X/fy2100Isup3.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
C4—H4⋯O5ⁱ	0.95	2.57	3.505 (3)	168
C7—H7⋯O1ⁱⁱ	0.95	2.40	3.247 (3)	149
C8—H8B⋯O3ⁱ	0.98	2.59	3.432 (4)	144

Open in a new tab

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

Acknowledgments

This work was supported financially by the Xunta de Galicia (CN 2012/184). The authors gratefully acknowledge Dr Berta Covelo, X-ray service of the University of Vigo, for her valuable assistance. NV thanks the University of Vigo for a PhD fellowship.

supplementary crystallographic information

1. Comment

Phthalimide derivatives represent a significant family of organic compounds because of their numerous applications in different fields of chemistry. They are not only useful intermediates for synthesis (Luzzio, 2005), but are also important scaffolds for new materials (Barooah & Baruah, 2007) and drug design (Sharma et al., 2010). Among the phthalimide analogues, there are very well known N-benzyl substituted derivatives, some of them prepared for mechanistic studies on photoreactions (Warzecha, Görner et al., 2006). Reaction of phthalic acid derivatives with benzylamines at high temperature or in the presence of a Lewis acid are the classical methods for obtaining N-benzylphthalimides (Favor et al., 2008; Haj-Yehia & Khan, 2004; Luzzio, 2005). In addition, unconventional approaches were also developed, such as carbonylative cyclizations of arenes with amines catalyzed by transition metals (Cao & Alper, 2010) or microwave-assisted synthesis (Vidal et al., 2000).

The title compound (I) is a N-benzylphthalimide substituted at C5 with a methoxy group. It was obtained by the reaction of dimethyl phthalimide with benzyl hydrazine under microwave irradiation.

The molecular structure of (I) is illustrated in Figure 1. There are some similar structures reported before (Warzecha et al., 2006a; Warzecha et al., 2006b; Warzecha et al., 2006c; Jiang et al., 2008). The molecule consists of two planar moieties, the phthalimide system and the phenyl ring, linked by the methylene group C9 (N2—C9—C10 bond angle of 114.4°), resulting in a non-planar structure. The two planar subunits make a dihedral angle of 84.7 (6)°, which is similar to the value reported for the same angle in the crystal structure of the monoclinic form of the parent N-benzylphthalimide (Jiang et al., 2008). Furthermore, the methoxy group at C5 is almost coplanar with the phathalimide ring [torsion angle C4—C5—O5—C8 of -171.5 (2)°].

In addition, the C1—N2—C9—C10 and C3—N2—C9—C10 torsion angles of 93.1 (3)° and -86.0 (3)°, respectively, are also very similar to those of N-benzylphthalimide (Jiang et al., 2008) and they corroborate that the phenyl group is virtually orthogonal to the phthalimide benzene ring. In the crystal structure, the molecules are self-assembled via non-classical C—H···O hydrogen bonds, involving CH and CH₃ groups as donors and oxygen atoms as acceptors, to form a one-dimensional supramolecular organization (Table 1, Figure 2).

2. Experimental

The synthesis of 2-benzyl-5-methoxyisoindoline-1,3-dione was carried out in a microwave oven (CEM discover system 908010, monomode) according to the following protocol: a solution of dimethyl 4-methoxyphthalate (50 mg, 0.22 mmol), benzylhydrazine dihydrochloride (174 mg, 0.89 mmol) and triethylamine (0.37 ml, 2.65 mmol), in ethanol (5 ml) was introduced in a Pyrex flask and submitted to microwave irradiation (280 W, 185 °C) for 30 min. The solvent was evaporated under reduced pressure and the residue was purified by column chromatography on silica gel (hexane/ethyl acetate 40:1 → 20:1) to afford a white solid (9.3 mg, 15%). The product was dissolved in ethyl acetate (3 ml) and the solution was kept at room temperature for 1 d. Natural evaporation gave colourless block-like crystals of the title compound (m.p. 448–449 K) suitable for X-ray diffraction analysis.