Crystal structure of 2-amino-4-(4-meth­oxy­phen­yl)-4H-benzo[g]chromene-3-carbo­nitrile

Joel T Mague; Shaaban K Mohamed; Mehmet Akkurt; Sabry H H Younes; Mustafa R Albayati

doi:10.1107/S205698901502280X

. 2015 Dec 6;71(Pt 12):o1017–o1018. doi: 10.1107/S205698901502280X

Crystal structure of 2-amino-4-(4-methoxyphenyl)-4H-benzo[g]chromene-3-carbonitrile

Joel T Mague ^a, Shaaban K Mohamed ^b,^c, Mehmet Akkurt ^d, Sabry H H Younes ^e, Mustafa R Albayati ^f,^*

PMCID: PMC4719954 PMID: 26870473

Abstract

In the title compound, C₂₁H₁₆N₂O₂, the naphthalene fragment is twisted slightly, as indicated by the dihedral angle of 3.2 (2)° between the two six-membered rings. The pendant 4-methoxyphenyl ring makes a dihedral angle of 86.08 (6)° with the central six-membered ring of the 4H-benzo[g]chromene ring system. In the crystal, molecules are linked by pairs of N—H⋯N hydrogen bonds, forming inversion dimers which are linked into chains propagating in the b-axis direction by N—H⋯O hydrogen bonds.

Keywords: crystal structure, chromenes, benzopyrans, 2-amino-3-cyano-4H-chromene derivatives, 4H-chromene and fused 4H-chromene derivatives, hydrogen bonding

Related literature

For the chemical and pharmacological properties of 4H-chromene and fused 4H-chromene derivatives, see: Bonsignore et al. (1993 ▸); Martínez-Grau & Marco (1997 ▸); Abd-El-Aziz et al. (2007 ▸); Sabry et al. (2011 ▸). For the synthesis and biological activities of 2-amino-3-cyano-4H-chromene derivatives, see: Kemnitzer et al. (2005 ▸); Patil et al. (2012 ▸); Kumar et al. (2009 ▸).

Experimental

Crystal data

C₂₁H₁₆N₂O₂
M _r = 328.36
Triclinic,
a = 6.3833 (2) Å
b = 10.6009 (3) Å
c = 13.0915 (4) Å
α = 108.823 (2)°
β = 95.906 (2)°
γ = 97.467 (2)°
V = 821.44 (4) Å³
Z = 2
Cu Kα radiation
μ = 0.69 mm⁻¹
T = 150 K
0.26 × 0.20 × 0.02 mm

Data collection

Bruker D8 VENTURE PHOTON 100 CMOS diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2015 ▸) T _min = 0.78, T _max = 0.99
6215 measured reflections
3039 independent reflections
2074 reflections with I > 2σ(I)
R _int = 0.048

Refinement

R[F ² > 2σ(F ²)] = 0.057
wR(F ²) = 0.151
S = 1.03
3039 reflections
235 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.22 e Å⁻³

Data collection: APEX2 (Bruker, 2015 ▸); cell refinement: SAINT (Bruker, 2015 ▸); data reduction: SAINT; program(s) used to solve structure: SHELXT (Sheldrick, 2015a ▸); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b ▸); molecular graphics: DIAMOND (Brandenburg & Putz, 2012 ▸); software used to prepare material for publication: SHELXTL (Sheldrick, 2008 ▸).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S205698901502280X/su5248sup1.cif

e-71-o1017-sup1.cif^{(201.7KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S205698901502280X/su5248Isup2.hkl

e-71-o1017-Isup2.hkl^{(242.8KB, hkl)}

Click here for additional data file.^{(6.4KB, cml)}

Supporting information file. DOI: 10.1107/S205698901502280X/su5248Isup3.cml

Click here for additional data file.^{(1.5MB, tif)}

. DOI: 10.1107/S205698901502280X/su5248fig1.tif

The molecular structure of the title compound with the labeling scheme and 50% probability displacement ellipsoids.

Click here for additional data file.^{(1.1MB, tif)}

c . DOI: 10.1107/S205698901502280X/su5248fig2.tif

View along the c axis of one hydrogen-bonded layer. The N—H⋯N and N—H⋯O hydrogen bonds (see Table 1) are shown as blue and purple dotted lines, respectively.

Click here for additional data file.^{(1.4MB, tif)}

. DOI: 10.1107/S205698901502280X/su5248fig3.tif

Crystal packing viewed along the c axis, with the N—H⋯N and N—H⋯O hydrogen bonds (see Table 1) shown as blue and purple dotted lines, respectively.

CCDC reference: 1439459

Additional supporting information: 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—H2A⋯N1ⁱ	0.96 (3)	2.03 (3)	2.995 (3)	178 (3)
N2—H2B⋯O2ⁱⁱ	0.95 (3)	2.10 (3)	3.028 (3)	166 (2)

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

Acknowledgments

The support of NSF–MRI Grant No. 1228232 for the purchase of the diffractometer and Tulane University for support of the Tulane Crystallography Laboratory are gratefully acknowledged.

supplementary crystallographic information

S1. Structural commentary

Fused benzo-4H-pyran, namely, 4H-chromene moiety, is the key building block of many oxygen-containing heterocyclic natural products whose pharmacological and biological activity such as anti-tumor, anti-oxidant, anti-bacterial, anti-viral, anti-fungal, hypotensive, anti-coagulant, anti-leishmanial, diuretic, and anti-allergenic activities (Bonsignore et al., 1993; Martínez-Grau & Marco, 1997; Abd-El-Aziz et al., 2007; Sabry et al., 2011). Moreover, 2-amino-3-cyano-4H-chromene derivatives have been also used as anti-cancers, inhibitors of insulin-regulated aminopeptidase (IRAP) for enhancing memory and learning functions and anti-bacterial agents (Kemnitzer et al., 2005; Patil et al., 2012; Kumar et al., 2009). In continuation of our interest in the chemical and pharmacological properties of 4H-chromene and fused 4H-chromene derivatives, we herein report on the synthesis and crystal structure of the title compound.

In the title compound, Fig. 1, the naphthalene fragment is slightly twisted as indicated by the dihedral angle of 3.2 (2)° between the two 6-membered rings. The pendant 4-methoxyphenyl ring makes a dihedral angle of 86.08 (6)° with the (C4—C7/C12/C13) ring. The heterocyclic ring (O1/C1—C4/C13) can best be described as having an envelope conformation, with atom C3 as the flap, and with pucking parameters of Q = 0.099 (2) Å, θ = 109.8 (12)° and φ = 6.5 (14)°.

In the crystal, pairwise N2—H2A···N1ⁱ hydrogen bonds form inversion dimers which are linked into chains running along the b axis direction (Fig. 2 and Table 1). The overall packing of these units in the crystal is illustrated in Fig. 3.

S2. Synthesis and crystallization

To a solution of 4-methoxybenzylidene-malononitrile (1 mmol, 180 mg) in 10 ml of ethanol was added 4- 1-naphthol (1 mmol, 144 mg) in the presence of few catalytic drops of piperedine and the temperature was adjusted at 353 K for 1 h. A solid product was obtained on cooling, collected by filtration and recrystallized from ethanol to afford colorless plate-like crystals suitable for X-ray diffraction analysis.

S3. Refinement

The NH₂ H-atoms were located in a difference Fourier map and freely refined. The C-bound H atoms were placed in calculated positions (C—H = 0.95 − 1.00 Å) and included as riding contributions with U_iso(H) = 1.5U_eq(C-methyl) and 1.2U_eq(C) for other H atoms.