Crystal structure of 5-di­ethyl­amino-2-({[4-(di­ethyl­amino)­phen­yl]imino}­meth­yl)phenol

C Vidya Rani; G Chakkaravarthi; N Indra Gandhi; G Rajagopal

doi:10.1107/S205698901501645X

. 2015 Sep 12;71(Pt 10):o712–o713. doi: 10.1107/S205698901501645X

Crystal structure of 5-diethylamino-2-({[4-(diethylamino)phenyl]imino}methyl)phenol

C Vidya Rani ^a, G Chakkaravarthi ^b,^*, N Indra Gandhi ^c,^*, G Rajagopal ^a

PMCID: PMC4647405 PMID: 26594437

Abstract

In the title compound, C₂₁H₂₉N₃O, the dihedral angle between the planes of the aromatic rings is 8.1 (2)°. The ethyl groups at one terminal site of the compound are disordered over two sets of sites with occupancies of 0.775 (9) and 0.225 (9). The molecule has an E conformation about the N=C bond. The molecular structure features an intramolecular O—H⋯N hydrogen bond, which closes an S(6) loop. In the crystal, weak C—H⋯π interactions leads to the formation of a three-dimensional network.

Keywords: crystal structure, phenol, Schiff base, intramolecular hydrogen bond, C—H⋯π interactions, biological activity, pharmacological activity

Related literature

For biological and pharmacological activities of Schiff base compounds and their derivatives, see: Khandar et al. (2005 ▸); Chen et al. (2006 ▸); Kidwai et al. (2000 ▸). For similar structures, see: Manvizhi et al. (2011 ▸); Thirugnanasundar et al. (2011 ▸); Rani et al. (2015 ▸).

Experimental

Crystal data

C₂₁H₂₉N₃O
M _r = 339.47
Orthorhombic,
a = 8.1986 (4) Å
b = 9.7128 (4) Å
c = 24.4172 (12) Å
V = 1944.38 (16) Å³
Z = 4
Mo Kα radiation
μ = 0.07 mm⁻¹
T = 295 K
0.28 × 0.26 × 0.24 mm

Data collection

Bruker Kappa APEX II CCD diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▸) T _min = 0.980, T _max = 0.983
29557 measured reflections
3556 independent reflections
2130 reflections with I > 2σ(I)
R _int = 0.046

Refinement

R[F ² > 2σ(F ²)] = 0.064
wR(F ²) = 0.205
S = 1.07
3556 reflections
272 parameters
10 restraints
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.44 e Å⁻³
Δρ_min = −0.20 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: PLATON (Spek, 2009 ▸); software used to prepare material for publication: SHELXL97 and PLATON (Spek, 2009 ▸).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S205698901501645X/rk2432sup1.cif

e-71-0o712-sup1.cif^{(32.5KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S205698901501645X/rk2432Isup2.hkl

e-71-0o712-Isup2.hkl^{(170.9KB, hkl)}

Click here for additional data file.^{(7.4KB, cml)}

Supporting information file. DOI: 10.1107/S205698901501645X/rk2432Isup3.cml

Click here for additional data file.^{(987.1KB, tif)}

2 5 2 . DOI: 10.1107/S205698901501645X/rk2432fig1.tif

The molecular structure of title compaund, with the atom–numbering scheme. Displacement ellipsoids are drawn at the 30% probability level. H atoms are presented as a small spheres of arbitrary radius. The intramolecular hydrogen bond is depicted by a dashed line. Only the major occupancy component of the disordered diethylamino–group [—N1(C₂H₅)₂] is shown.

CCDC reference: 1422036

Additional supporting information: crystallographic information; 3D view; checkCIF report

Table 1. Hydrogen-bond geometry (, ).

Cg1 and Cg2 are the centroids of the C5C10 and C12C17 rings, respectively.

DHA	DH	HA	D A	DHA
O1H1N2	0.86(2)	1.81(4)	2.563(5)	144(6)
C18H18A Cg2ⁱ	0.97	2.92	3.660(5)	134
C1AH1A1Cg1ⁱⁱ	0.96	2.80	3.49(4)	130

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

Acknowledgments

The authors acknowledge the SAIF, IIT, Madras, for the data collection.

supplementary crystallographic information

S1. Comment

Schiff base derivatives serve as intermediates in certain enzymatic reactions and are also found in proteins that form the connective tissue (Khandar et al., 2005; Chen et al., 2006) and in the pharmaceutical field (Kidwai et al., 2000). We herein report the crystal structure of the title compound (Fig.1). The geometric parameters of the title compound are comparable to the reported structures (Manvizhi et al., 2011; Thirugnanasundar et al., 2011; Rani et al., 2015). The dihedral angle between the rings (C5–C10) and (C12–C17) is 8.1 (2)°. The ethyl groups at one terminal site (N1) of the compound are disordered over two positions, with the site occupancies of 0.775 (9) and 0.225 (9). The molecular structure is stabilized by weak intramolecular O—H···N hydrogen bond (Table 1). The crystal structure is influenced by weak C—H···π (Table 1) interactions to form a three dimensional network.

S2. Experimental

For the preparation of Schiff base, an ethanolic solution (10 ml) of 5–(diethylamino)–2–hydroxybenzaldehyde (0.5 mol) and the same volume of ethanolic solution of N,N–diethylbenzene–1,4–diamine (0.5 mol) are mixed. The solution is mixed on magnetic stirrer with addition of 2 to 3 drops of glacial acetic acid. The reaction mixture is refluxed for 2 hrs and allowed to cool down to room temperature, crystalline solid precipitate from the mixture is separated out. Crystalline products are washed with ice cold ethanol and dried in vacuo over anhydrous CaCl₂. Single crystals suitable for the X-ray diffraction are obtained by slow evaporation of a solution of the title compound in DMF at room temperature.