2-Amino-N-(2-hydr­oxy-3-methoxy­benzyl­idene)aniline

Mohammed H Al-Douh; Shafida A Hamid; Hasnah Osman; Reza Kia; Hoong-Kun Fun

doi:10.1107/S1600536808016292

. 2008 Jun 7;64(Pt 7):o1201–o1202. doi: 10.1107/S1600536808016292

2-Amino-N-(2-hydroxy-3-methoxybenzylidene)aniline

Mohammed H Al-Douh ^a, Shafida A Hamid ^a,^‡, Hasnah Osman ^a, Reza Kia ^b, Hoong-Kun Fun ^b,^*

PMCID: PMC2961787 PMID: 21202842

Abstract

In the title compound, C₁₄H₁₄N₂O₂, the dihedral angle between the two benzene rings is 9.67 (10)°. Two intramolecular O—H⋯N and N—H⋯N hydrogen bonds involving the hydroxy and amino groups generate S(6) and S(5) ring motifs, respectively. In the crystal structure, N—H⋯O hydrogen bonds link neighboring molecules. Molecules are also stacked in a head-to-tail fashion along the c axis through π–π interactions [centroid–centroid separation of 3.7357 (12) Å] and are further linked by weak intermolecular C—H⋯π interactions, giving a zigzag arrangement along the b axis.

Related literature

For related literature on hydrogen bond motifs, see: Bernstein et al. (1995 ▶). For values of bond lengths, see: Allen et al. (1987 ▶). For the biological activity of imines, see, for example: Singh & Dash (1988 ▶); More et al. (2001 ▶); Baseer et al. (2000 ▶); El-Masry et al. (2000 ▶); Kabeer et al. (2001 ▶); Kuz’min et al. (2000 ▶); Desai et al. (2001 ▶). For related structures, see, for example: Corden et al. (1996 ▶); Govindasamy et al. (1999 ▶). For synthesis, see: Al-Douh et al. (2006 ▶, 2007 ▶). For related literature, see: Berger (2001 ▶); Elerman & Kabak (1997 ▶); Latif et al. (1983 ▶); Liu et al. (2006 ▶); Shah et al. (2008 ▶).

Experimental

Crystal data

C₁₄H₁₄N₂O₂
M _r = 242.27
Monoclinic,
a = 13.2790 (6) Å
b = 14.4810 (6) Å
c = 6.1928 (3) Å
β = 103.116 (3)°
V = 1159.77 (9) Å³
Z = 4
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 100.0 (1) K
0.45 × 0.15 × 0.05 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ▶) T _min = 0.959, T _max = 0.996
19968 measured reflections
3402 independent reflections
2532 reflections with I > 2σ(I)
R _int = 0.052

Refinement

R[F ² > 2σ(F ²)] = 0.072
wR(F ²) = 0.206
S = 1.06
3402 reflections
194 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.66 e Å⁻³
Δρ_min = −0.31 e Å⁻³

Data collection: APEX2 (Bruker, 2005 ▶); cell refinement: APEX2; data reduction: SAINT (Bruker, 2005 ▶); program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2003 ▶).

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536808016292/sj2510sup1.cif

e-64-o1201-sup1.cif^{(17.9KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536808016292/sj2510Isup2.hkl

e-64-o1201-Isup2.hkl^{(166.9KB, hkl)}

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (Å, °).

Cg1 and Cg2 are centroids of the C1–C6 and C8–C13 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
O1—H1O1⋯N1	0.88	1.77	2.602 (2)	158
N2—H1N2⋯O1ⁱ	0.93 (3)	2.56 (3)	3.030 (3)	111 (2)
N2—H1N2⋯O2ⁱ	0.93 (3)	2.29 (3)	3.181 (3)	161 (3)
N2—H2N2⋯N1	0.87 (3)	2.23 (3)	2.759 (3)	119 (2)
C3—H3⋯Cg1ⁱⁱ	0.94 (3)	2.64 (3)	3.458 (2)	145 (2)
C11—H11⋯Cg2ⁱⁱⁱ	0.91 (3)	2.87 (3)	3.538 (2)	142 (2)

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

Acknowledgments

The authors thank the Malaysian Government and Universiti Sains Malaysia (USM) for an IRPA short-term grant (No. 304/PKIMIA/638007) to conduct this work. MHA thanks the Yemen Government and Hadhramout University of Science and Technology (HUST) for financial scholarship support. HKF and RK thank the Malaysian Government and Universiti Sains Malaysia for Science Fund grant No. 305/PFIZIK/613312. RK thanks Universiti Sains Malaysia for a post-doctoral research fellowship.

supplementary crystallographic information

Comment

Imines are an important class of compounds and rank among the most versatile synthetic organic intermediates, which are important for the synthesis of biologically important compounds (Singh & Dash, 1988; More et al., 2001; Baseer et al., 2000; El-Masry et al., 2000; Kabeer et al., 2001; Kuz'min et al., 2000; Desai et al., 2001). Berger (2001) evaluated some bis-Schiff bases using 1138 and Sc-7 yeast assays, and a A2780 cytotoxicity test. They showed significant activity in a single dose test. The reactions of some phenolic aldehydes with o-phenylenediamine have been examined in some detail including the isolation of the title compound (Latif et al., 1983). Our group has been actively involved in synthesizing bis-Schiff bases and investigating their DNA binding ability using spectroscopic techniques employing calf thymus DNA (Shah et al., 2008). We have also obtained single crystals of benzimidazole and the bis-Schiff base derived from the title compound (I) and their structures are consistent with those reported earlier (Elerman & Kabak, 1997; Liu et al., 2006). However, the crystal structure of compound (I) was never reported and we present its structure here (Fig. 1).

The C1–C6 benzene ring is not coplanar with the phenylenediamine and makes a dihedral angle of 9.67 (10)° with C8–C13 benzene ring. Two intramolecular O1—H1O1···N1 and N2—H2N2···N1 hydrogen bonds generate S(6) and S(5) ring motifs, respectively (Bernstein et al., 1995). Bond lengths and angles in the title compound have normal values (Allen et al., 1987). The crystal is stabilized by intramolecular O—H···N and N—H···N and intermolecular N—H···O hydrogen bonds. Molecules (Fig. 2) are also arranged into zig-zag chains by C—H···π interactions along the b-axis (Table 1); Cg1 and Cg2 are the centroids of the C1–C6 and C8–C13 phenyl rings, respectively. In the crystal packing (Fig. 3), molecules are stacked along the c axis by π···π interactions with Cg1···Cg2 = 3.7357 (12) Å: symmetry codes x, y, -1 + z and x, y, 1 + z;

Experimental

The synthetic method has been described earlier (Al-Douh et al., 2006, 2007). Single crystals suitable for X-ray diffraction were obtained by evaporation of a n-hexane solution at room temperature.