Ethyl 2-amino-4-(4-fluoro­phen­yl)-6-meth­oxy-4H-benzo[h]chromene-3-carboxyl­ate

Ahmed M El-Agrody; Mohamed A Al-Omar; Abdel-Galil E Amr; Tze Shyang Chia; Hoong-Kun Fun

doi:10.1107/S1600536812021939

. 2012 May 19;68(Pt 6):o1803–o1804. doi: 10.1107/S1600536812021939

Ethyl 2-amino-4-(4-fluorophenyl)-6-methoxy-4H-benzo[h]chromene-3-carboxylate

Ahmed M El-Agrody ^a, Mohamed A Al-Omar ^b,^c, Abdel-Galil E Amr ^c,^d, Tze Shyang Chia ^e, Hoong-Kun Fun ^e,^*,^‡

PMCID: PMC3379378 PMID: 22719576

Abstract

In the title compound, C₂₃H₂₀FNO₄, the fluoro-substituted benzene ring is approximately perpendicular to the mean plane of the 4H-benzo[h]chromene ring system [maximum deviation = 0.264 (1) Å], with a dihedral angle of 83.79 (6)°. The pyran ring adopts a flattened boat conformation. The methoxy group is slightly twisted from the attached benzene ring of the 4H-benzo[h]chromene moiety [C—O—C—C = −2.1 (2)°]. An intramolecular N—H⋯O hydrogen bond generates an S(6) ring motif. In the crystal, molecules are linked by N—H⋯O and N—H⋯F hydrogen bonds into a layer parallel to the bc plane. The crystal packing also features C—H⋯π interactions.

Related literature

For background to and applications of 4H-chromene and its derivatives, see: Jeso & Nicolaou (2009 ▶); Alvey et al. (2008 ▶, 2009 ▶); Symeonidis et al. (2009 ▶); Brühlmann et al. (2001 ▶); Bedair et al. (2001 ▶); El-Agrody et al. (2002 ▶, 2011 ▶); Abd-El-Aziz et al. (2004 ▶); Sabry et al. (2011 ▶). For ring puckering parameters, see: Cremer & Pople (1975 ▶). For hydrogen-bond motifs, see: Bernstein et al. (1995 ▶). graphic file with name e-68-o1803-scheme1.jpg

Experimental

Crystal data

C₂₃H₂₀FNO₄
M _r = 393.40
Monoclinic,
a = 12.6844 (3) Å
b = 16.1933 (4) Å
c = 9.4579 (2) Å
β = 94.288 (2)°
V = 1937.24 (8) Å³
Z = 4
Cu Kα radiation
μ = 0.82 mm⁻¹
T = 296 K
0.81 × 0.74 × 0.04 mm

Data collection

Bruker SMART APEXII CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2009 ▶) T _min = 0.556, T _max = 0.972
13713 measured reflections
3657 independent reflections
3009 reflections with I > 2σ(I)
R _int = 0.034

Refinement

R[F ² > 2σ(F ²)] = 0.039
wR(F ²) = 0.117
S = 1.08
3657 reflections
273 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.19 e Å⁻³
Δρ_min = −0.19 e Å⁻³

Data collection: APEX2 (Bruker, 2009 ▶); cell refinement: SAINT (Bruker, 2009 ▶); data reduction: SAINT; 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, 2009 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812021939/is5141sup1.cif

e-68-o1803-sup1.cif^{(29.9KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812021939/is5141Isup2.hkl

e-68-o1803-Isup2.hkl^{(179.3KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812021939/is5141Isup3.cml

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

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

Cg1, Cg2 and Cg3 are the centroids of C4–C6/C11–C13, C14–C19 and C6–C11 rings, respectively.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H2N1⋯O3ⁱ	0.89 (2)	2.23 (2)	3.0969 (19)	165.8 (17)
N1—H1N1⋯O3	0.89 (2)	2.111 (18)	2.7570 (18)	129.1 (16)
N1—H1N1⋯F1ⁱⁱ	0.89 (2)	2.32 (2)	3.034 (2)	137.6 (16)
C8—H8A⋯Cg1ⁱⁱⁱ	0.93	2.81	3.5633 (16)	139
C10—H10A⋯Cg2^iv	0.93	2.94	3.7003 (17)	140
C20—H20C⋯Cg3^iv	0.96	2.74	3.5896 (17)	148

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

Acknowledgments

HKF and TSC thank Universiti Sains Malaysia (USM) for the Research University Grant (1001/PFIZIK/811160). TSC also thanks the Malaysian Government and USM for the award of a research fellowship. The authors extend their appreciation to the Deanship of Scientific Research at King Saud University for funding the work through the research group project No. RGP-VPP-099.

supplementary crystallographic information

Comment

The 4H-chromene nucleus is frequently found in bioactive compounds and plays an important role in biochemical processes (Jeso & Nicolaou, 2009; Alvey et al., 2008, 2009; Symeonidis et al., 2009). In addition, 4H-chromenes and fused 4H-chromenes nuclei are used in treatment of Alzheimer's disease and Schizophrenia disorder (Brühlmann et al., 2001). In view of the above observations and in continuation of our program on the chemistry of 4H-pyran derivatives (Bedair et al., 2001; El-Agrody et al., 2002, 2011; Abd-El-Aziz et al., 2004; Sabry et al., 2011), we report herein the crystal structure of the title compound.

The asymmetric unit of the title compound is shown in Fig. 1. The fluoro-substituted benzene ring (C14–C19) is approximately perpendicular to the 4H-benzo[h]chromene ring system [O1/C1–C13, maximum deviation = 0.264 (1) Å at atom C2] as indicated by the dihedral angle of 83.79 (6)°. The pyran ring (O1/C1–C5) adopts a flattened boat conformation [puckering parameters (Cremer & Pople, 1975), Q = 0.2599 (13) Å, θ = 79.3 (3)° and φ = 170.9 (3)°]. The atoms O1 and C3 are deviating from the mean plane of C1/C2/C4/C5 by 0.1589 (18) and 0.2820 (21) Å, respectively. The methoxy group (C20/O2) is slightly twisted from the attached benzene ring (C4–C6/C11–C13) of the 4H-benzo[h]chromene moiety with the torsion angle C20—O2—C12—C13 of -2.1 (2)°. An intramolecular N1—H1N1···O3 hydrogen bond generates an S(6) ring motif (Bernstein et al., 1995) in the molecule.

In the crystal (Fig. 2), molecules are linked by intermolecular N1—H2N1···O3 and N1—H1N1···F1 hydrogen bonds (Table 1) into a layer parallel to the bc plane. The crystal packing is further stabilized by C—H···π interactions (Table 1), involving Cg1, Cg2 and Cg3 which are the centroids of C4–C6/C11–C13, C14–C19 and C6–C11 rings, respectively.

Experimental

A solution of 4-methoxy-1-naphthol (0.01 mol) in EtOH (30 ml) was treated with ethyl α-cyano-p-fluorocinnamate (0.01 mol) and piperidine (0.5 ml). The reaction mixture was heated under reflux for 2 h. The obtained solid product was collected by filtration, dried and crystallized from ethanol to give the title compound. M.p.: 435–436 K.