4-(4-Meth­oxy­phen­yl)-6-methyl­amino-5-nitro-2-phenyl-4H-pyran-3-carbonitrile

R Vishnupriya; J Suresh; S Sivakumar; R Ranjith Kumar; P L Nilantha Lakshman

doi:10.1107/S1600536813004923

. 2013 Feb 28;69(Pt 3):o451. doi: 10.1107/S1600536813004923

4-(4-Methoxyphenyl)-6-methylamino-5-nitro-2-phenyl-4H-pyran-3-carbonitrile

R Vishnupriya ^a, J Suresh ^a, S Sivakumar ^b, R Ranjith Kumar ^b, P L Nilantha Lakshman ^c,^*

PMCID: PMC3588539 PMID: 23476619

Abstract

In the title compound, C₂₀H₁₇N₃O₄, the central pyran ring adopts a boat conformation with the O atom and diagonally opposite C atoms displaced by 0.1171 (1) and 0.1791 (1) Å, respectively, from the mean plane defined by the other four atoms. The coplanar atoms of the pyran ring and the methoxybenzene ring are nearly perpendicular, as evidenced by the dihedral angle 87.01 (1)°. The amine H atom forms an intramolecular N—H⋯O(nitro) hydrogen bond. In the crystal, molecules are linked into dimeric aggregates by N—H⋯O(nitro) hydrogen bonds, generating an R ₂ ²(12) graph-set motif.

Related literature

For background to compounds containing the 4H-pyran unit, see: Brahmachari (2010 ▶); Hatakeyama et al. (1988 ▶). For 2-amino-4H-pyrans as photoactive materials, see: Armetso et al. (1989 ▶). For graph-set motifs, see: Bernstein et al. (1995 ▶). For ring conformation analysis, see: Cremer & Pople (1975 ▶).

Experimental

Crystal data

C₂₀H₁₇N₃O₄
M _r = 363.37
Monoclinic,
a = 22.9422 (10) Å
b = 7.5828 (3) Å
c = 22.7319 (10) Å
β = 112.576 (2)°
V = 3651.5 (3) Å³
Z = 8
Mo Kα radiation
μ = 0.09 mm⁻¹
T = 293 K
0.23 × 0.21 × 0.19 mm

Data collection

Bruker Kappa APEXII diffractometer
Absorption correction: multi-scan (SADABS; Sheldrick, 1996 ▶) T _min = 0.967, T _max = 0.974
15550 measured reflections
4003 independent reflections
2915 reflections with I > 2σ(I)
R _int = 0.028

Refinement

R[F ² > 2σ(F ²)] = 0.040
wR(F ²) = 0.116
S = 1.05
4003 reflections
246 parameters
H-atom parameters constrained
Δρ_max = 0.23 e Å⁻³
Δρ_min = −0.18 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.

Supplementary Material

Click here for additional data file.^{(20.7KB, cif)}

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536813004923/tk5197sup1.cif

e-69-0o451-sup1.cif^{(20.7KB, cif)}

Click here for additional data file.^{(192.3KB, hkl)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813004923/tk5197Isup2.hkl

e-69-0o451-Isup2.hkl^{(192.3KB, hkl)}

Click here for additional data file.^{(6.9KB, cml)}

Supplementary material file. DOI: 10.1107/S1600536813004923/tk5197Isup3.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
N2—H2⋯O2	0.86	2.00	2.6203 (19)	128
N2—H2⋯O2ⁱ	0.86	2.26	3.0114 (18)	147

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Symmetry code: (i) Inline graphic .

Acknowledgments

JS thanks the UGC for the FIST support. JS and RV thank the management of Madura College for their encouragement and support. RRK thanks the DST, NewDelhi, for funds under the fast-track scheme (No·SR/FT/CS-073/2009).

supplementary crystallographic information

Comment

4H-Pyran units constitute structural features of a broad range of bioactive natural products (Brahmachari, 2010; Hatakeyama et al., 1988). 2-Amino-4H-pyrans have also been found to be useful as photoactive materials (Armetso et al., 1989). Hence, investigation of the structural features of biologically relevant tetrahydrobenzo[b]pyran derivatives is of both scientific and practical interest. In continuation of our efforts to develop useful synthetic protocols for biologically significant molecules, we herein report an efficient and environmentally benign synthesis and the crystal structure of the title compound.

In the title compound, Fig. 1, the six-membered central pyran ring adopts a boat conformation as evidenced by the puckering parameters q₂ = 0.1713 (16) Å, θ = 98.1 (5)°, φ = 3.5 (6)° (Cremer & Pople, 1975). The dihedral angle between the methoxybenzene ring and the flat part of the pyran ring is 87.01 (1)° which means that the methoxybenzene ring is nearly perpendicular to the pyran ring. The acetonitrile group is almost coplanar with the plane of the pyrazole ring [the N3—C21—C2—C1 torsion angle is 174.04 (16) °]. The nitrile group has a typical bond length, i.e. N ≡C = 1.141 (3) Å. The dihedral angle between the flat part of the pyran ring and the phenyl ring is 38.62 (2)°. The phenyl ring is attached to the pyran ring by an (-)-syn-clinal conformation with torsion angle C12—C11—C1—C2 of -41.54 (3)°. Similarly, the methoxybenzene ring is attached to the pyran ring by a torsion angle C4—C3—C31—C36 of -59.51 (2)°, again indicating an (-)-syn-clinal conformation. The nitro group is attached to pyran ring at C4 with the torsion angle (C5—C4—N1—O2) of -4.89 (3)°, indicating an (-)-syn-periplanar conformation.

In the crystal structure, N2—H2···O2 hydrogen bonds link molecules into dimeric pairs, Table 1. Each of these pairs generate a graph set motif of R₂²(12) (Bernstein et al., 1995), Fig. 2. In addition, there is a N—H···O intramolecular interaction which stabilizes the structure.

Experimental

A mixture of benzoylacetonitrile (1.0 mmol), 4-methoxy aldehyde (1.0 mmol), Et₃N (1.0 mmol) and EtOH (10 ml) were taken in 50 ml round bottom flask. The reaction mixture was stirred at room temperature for 5–10 min. Then N-methyl-1-(methylthio)-2-nitroethenamine was added into the reaction mixture followed by refluxing at 353 K. The consumption of starting material was monitored by TLC. After 90 min, the solid product was filtered and washed with diethyl ether (5 ml) and dried under vacuum in 92% yield; M.pt: 481 K.