4-[4-(Diethyl­amino)­phen­yl]-N-methyl-3-nitro-4H-chromen-2-amine

J Muthukumaran; A Parthiban; P Manivel; H Surya Prakash Rao; R Krishna

doi:10.1107/S1600536811017338

. 2011 May 14;67(Pt 6):o1395–o1396. doi: 10.1107/S1600536811017338

4-[4-(Diethylamino)phenyl]-N-methyl-3-nitro-4H-chromen-2-amine

J Muthukumaran ^a, A Parthiban ^b, P Manivel ^a, H Surya Prakash Rao ^b,^‡, R Krishna ^a,^*

PMCID: PMC3120544 PMID: 21754782

Abstract

In the title compound, C₂₀H₂₃N₃O₃, the dihydropyran ring adopts half-chair conformation. The chromene system makes a dihedral angle of 87.35 (5)° with the adjacent benzene ring. An intramolecular N—H⋯O hydrogen bond generates an S(6) motif, which stabilizes the molecular conformation. In the crystal, weak intermolecular C—H⋯O hydrogen bonds contribute to the stabilization of the packing.

Related literature

For the biological importance of 4H-chromene derivatives, see: Cai (2007 ▶, 2008 ▶); Cai et al. (2006 ▶); Gabor (1988 ▶); Brooks (1998 ▶); Valenti et al. (1993 ▶); Hyana & Saimoto (1987 ▶); Afantitis et al. (2006 ▶); Tang et al. (2007 ▶). For the structures of 4H-chromene derivatives, see: Muthukumaran et al. (2011 ▶); Gayathri et al. (2006 ▶); Bhaskaran et al. (2006 ▶). For ring puckering analysis, see: Cremer & Pople (1975 ▶) and for hydrogen-bond motifs, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₀H₂₃N₃O₃
M _r = 353.41
Triclinic,
a = 8.9199 (11) Å
b = 10.4333 (12) Å
c = 11.6697 (8) Å
α = 65.100 (9)°
β = 82.388 (8)°
γ = 69.513 (11)°
V = 922.63 (19) Å³
Z = 2
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.45 × 0.35 × 0.35 mm

Data collection

Oxford Diffraction Xcalibur Eos diffractometer
Absorption correction: multi-scan (CrysAlis PRO; Oxford Diffraction, 2009 ▶) T _min = 0.923, T _max = 1.000
17119 measured reflections
3242 independent reflections
2625 reflections with I > 2σ(I)
R _int = 0.036

Refinement

R[F ² > 2σ(F ²)] = 0.056
wR(F ²) = 0.162
S = 1.05
3242 reflections
226 parameters
3 restraints
H-atom parameters constrained
Δρ_max = 0.52 e Å⁻³
Δρ_min = −0.44 e Å⁻³

Data collection: CrysAlis CCD (Oxford Diffraction, 2009 ▶); cell refinement: CrysAlis RED (Oxford Diffraction, 2009 ▶); data reduction: CrysAlis RED; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008 ▶); molecular graphics: ORTEP-3 for Windows (Farrugia, 1997 ▶) and PLATON (Spek, 2009 ▶); software used to prepare material for publication: PLATON.

Supplementary Material

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536811017338/sj5141sup1.cif

e-67-o1395-sup1.cif^{(22.1KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536811017338/sj5141Isup2.hkl

e-67-o1395-Isup2.hkl^{(159.1KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536811017338/sj5141Isup3.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
N1—H1⋯O2	0.86	1.96	2.596 (2)	129
C5—H5⋯O3ⁱ	0.93	2.52	3.325 (3)	144

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Symmetry code: (i) Inline graphic .

Acknowledgments

RK, JM and PM thank the Centre for Bioinformatics (Funded by the Department of Biotechnology and the Department of Information Technology, New Delhi, India), Pondicherry University for providing the computational facilities to carry out this work. AP thanks Pondicherry University for a Fellowship. PM also thanks the University Grants Commission (UGC) for a Fellowship. JM also thanks the Council for Scientific and Industrial Research (CSIR) for a Senior Research Fellowship (SRF). HSP thanks the UGC for the Special Assistance Programme (SAP) and the Department of Science and Technology (DST) for the Fund for Improvement of Science and Technology Infrastructure in Universities and Higher Educational Institutions (FIST).

supplementary crystallographic information

Comment

4H-chromenes and their derivatives possess various biological and pharmacological properties such as anti-viral, anti-fungal, anti-inflammatory, antidiabetic, cardionthonic, anti-anaphylactic and anti-cancer activity (Cai, 2008; Cai, 2007; Cai et al., 2006; Gabor,1988; Brooks,1998; Valenti et al., 1993; Hyana & Saimoto, 1987; Tang et al., 2007). 4-aryl-4H-chromenes are a new series of apoptosis inducers, which exhibit potent anticancer activity (Afantitis et al., 2006). Considering the importance of 4-aryl-4H-chromene derivatives, a single-crystal X-ray diffraction study on the title compound was carried out and analyzed.

Some 4H-chromene derivatives are already reported in the literature (Muthukumaran et al., 2011; Gayathri et al., 2006; Bhaskaran et al., 2006). The molecular structure of the title compound is shown in Fig. 1. From the puckering analysis (Cremer & Pople, 1975), the fused dihydropyran ring (O1/C1/C6/C7/C8/C9) of 4H-chromene system is very similar to half chair (H form) conformation with puckering parameters of Q = 0.253 (2) Å, θ = 103.2 (5) ° and Φ = 7.0 (5) °. In the title compound, the 4H-chromene system makes a dihedral angle of 87.35 (5)° with the adjacent phenyl ring. The intramolecular N1—H1···O2 interaction generates a graph-set motif S (6) (Bernstein et al., 1995) (Fig. 2) with a D···A bond distance of 2.596 (2) Å. The crystal packing (Fig. 3) is stabilized by weak intermolecular C—H···O interactions.

Experimental

To a vigorously stirred solution of N-methyl-N-[3-nitro-4-(methylsulfanyl)-4H-2-chromenyl]amine (0.5 g, 2 mmol) in ethanol (15 ml), N, N-diethylaminobenzene (0.33 g, 2.2 mmol) was added and the resulting solution was refluxed for 12 h by which time the reaction was complete (TLC; hexane: EtOAc, 6:4). The reaction mixture was cooled to room temperature and kept aside for 3 h. The solid, which separated was filtered to obtain 0.59 g of N2-methyl-4-[4-(diethylamino)phenyl]-3-nitro-4H-2-chromenamine in 92% yield as colorless solid; mp 201 °C. R_f 0.4 (hexane: EtOAc, 6:4). A sample suitable for single crystal X-ray analysis was obtained by recrystallization from a mixture of dichloromethane and hexane (3:1).