Methyl (E)-2-[(3-chloro-4-cyano­phenyl)­imino]-4-(4-chloro­phen­yl)-6-methyl-1,2,3,4-tetra­hydro­pyrimidine-5-carboxyl­ate

K N Venugopala; Susanta K Nayak; Bharti Odhav

doi:10.1107/S1600536812039451

. 2012 Sep 22;68(Pt 10):o2977–o2978. doi: 10.1107/S1600536812039451

Methyl (E)-2-[(3-chloro-4-cyanophenyl)imino]-4-(4-chlorophenyl)-6-methyl-1,2,3,4-tetrahydropyrimidine-5-carboxylate

K N Venugopala ^a,^*, Susanta K Nayak ^b,^*, Bharti Odhav ^a

PMCID: PMC3470343 PMID: 23125756

Abstract

In the title compound, C₂₀H₁₆Cl₂N₄O₂, the dihedral angles between the planes of the chlorophenyl, chlorocyanophenylimine and ester groups and the plane of the six-membered tetrahydropyrimidine ring are 86.9 (2), 72.6 (2) and 7.9 (2)°, respectively. The Cl atom substituent on the cyanophenyl ring is disordered over two rotationally related sites [occupancy factors 0.887 (2):0.113 (2)], while the molecular conformation is stabilized by the presence of an intramolecular aromatic C—H⋯π interaction. Both N—H groups participate in separate intermolecular hydrogen-bonding associations with centrosymmetric cyclic motifs [graph sets R ₂ ²(8) and R ₂ ²(12)], resulting in ribbons parallel to [010]. Further weak C—H⋯O hydrogen bonds link these ribbons into a two-dimensional molecular assembly.

Related literature

For crystal structures of the dihydropyrimidines, see: Nayak et al. (2010 ▶); Nayak, Venugopala, Govender et al. (2011 ▶); Nayak, Venugopala, Chopra & Guru Row (2011 ▶). For background on the applications of dihydropyrimidines, see: Kappe (2000 ▶). For graph-set analysis, see: Bernstein et al. (1995 ▶).

Experimental

Crystal data

C₂₀H₁₆Cl₂N₄O₂
M _r = 415.27
Monoclinic,
a = 11.905 (8) Å
b = 13.729 (9) Å
c = 12.782 (8) Å
β = 108.366 (14)°
V = 1983 (2) Å³
Z = 4
Mo Kα radiation
μ = 0.35 mm⁻¹
T = 173 K
0.23 × 0.12 × 0.03 mm

Data collection

Bruker Kappa DUO APEXII diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T _min = 0.924, T _max = 0.990
9454 measured reflections
3497 independent reflections
2324 reflections with I > 2σ(I)
R _int = 0.029
Standard reflections: 0

Refinement

R[F ² > 2σ(F ²)] = 0.046
wR(F ²) = 0.130
S = 1.01
3497 reflections
259 parameters
H-atom parameters constrained
Δρ_max = 0.41 e Å⁻³
Δρ_min = −0.37 e Å⁻³

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT; 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 Mercury (Macrae et al., 2008 ▶); software used to prepare material for publication: PLATON (Spek, 2009 ▶) and PARST (Nardelli, 1995 ▶).

Supplementary Material

Crystal structure: contains datablock(s) global, I. DOI: 10.1107/S1600536812039451/zs2233sup1.cif

e-68-o2977-sup1.cif^{(29.3KB, cif)}

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536812039451/zs2233Isup2.hkl

e-68-o2977-Isup2.hkl^{(168KB, hkl)}

Supplementary material file. DOI: 10.1107/S1600536812039451/zs2233Isup3.cml

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

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

Cg1 is the mid-point of the C3=C4 bond.

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
N1—H1⋯N4A ⁱ	0.88	2.21	2.981 (4)	147
N2—H2⋯N3ⁱⁱ	0.88	2.09	2.966 (4)	172
C15A—H15A⋯O1ⁱⁱⁱ	0.95	2.39	3.322 (4)	169
C12—H12⋯Cg1	0.95	2.85	3.290 (2)	109

Open in a new tab

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

Acknowledgments

The authors thank Durban University of Technology for facilities. KNV thanks NRF South Africa for a DST/NRF Innovation Postdoctoral Fellowship.

supplementary crystallographic information

Comment

The multifunctionalized dihydropyrimidones (DHPMs) are prime target molecules for their therapeutic and pharmacological properties (Kappe, 2000). Due to the vast range of applications of this class of compounds we have been investigating conformational and packing features of tetrahydropyrimidine derivatives of this title compound (Nayak et al., 2010; Nayak, Venugopala, Govender et al., 2011; Nayak, Venugopala, Chopra & Guru Row (2011). In a continuation of our work on synthesis of heterocyclic compounds for biological properties, herein we report the single-crystal structure of the title compound, C₂₀H₁₆Cl₂N₄O₂.

In this molecule (Fig. 1), the dihedral angles between the planes of the 4-chlorophenyl, 3-chloro-4-cyanophenylimino and ester groups (O2/C2/O1/C1) and the plane of the six-membered tetrahydropyrimidine ring are 86.9 (2)°, 72.6 (2)° and 7.9 (2)° respectively. The conformation of the molecule is stabilized by an intra-molecular C—H···π interaction (Table 1) wherein the aryl hydrogen H12 is oriented towards the π electrons of the C3═C4 bond. The meta-related chlorine substituent on the cyanophenyl ring is disordered over two rotationally-related sites [occupancy factors 0.887 (2) (A): 0.113 (2) B]. Both N—H groups participate in separate intermolecular hydrogen-bonding associations giving centrosymmetric cyclic motifs [graph sets R₂²(8) and R₂²(12) (Bernstein et al., 1995)], resulting in ribbons parallel to [010] (Fig. 2a). Further weak C—H···O hydrogen bonds (Fig. 2b) link these ribbons into a two-dimensional molecular assembly. Present also is a short intermolecular Cl···Cl interaction [Cl1···Cl2B^iv; 2.884 (7) Å (symmetry code -x + 1, y, -z - 1/2)].

Experimental

A mixture of methyl-2-chloro-4-(p-chlorophenyl)-6-methyl-1,4-dihydropyrimidine-5-carboxylate (1 mmol), 4-amino-2-chlorobenzonitrile (1 mmol) and methanamine (1 mmol) in 2-propanol (5 ml) was refluxed for 10 h. The reaction completion was monitored by TLC. The reaction medium was cooled to room temperature, the product was filtered, washed with cold 2-propanol and dried to obtain the crude product. The product was purified by recrystallization using ethanol in 69% yield as a yellow solid (m.p. 431 (2) K). Crystals suitable for single-crystal X-ray study were obtained from methanol solvent using slow evaporation at room temperature.