1,1′-[4-(2,4-Dichloro­phen­yl)-2,6-di­methyl-1,4-di­hydro­pyridine-3,5-di­yl]diethanone

J Kalyana Sundar; B Palakshi Reddy; V Vijayakumar; S Natarajan; J Suresh; P L Nilantha Lakshman

doi:10.1107/S1600536810052839

. 2011 Jan 15;67(Pt 2):o380–o381. doi: 10.1107/S1600536810052839

1,1′-[4-(2,4-Dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-diyl]diethanone

J Kalyana Sundar ^a, B Palakshi Reddy ^b, V Vijayakumar ^b, S Natarajan ^a, J Suresh ^c, P L Nilantha Lakshman ^d,^*

PMCID: PMC3051630 PMID: 21523057

Abstract

In the title compound, C₁₇H₁₇Cl₂NO₂, the central 1,4-dihydropyridine ring adopts a flattened-boat conformation. The ethanone substituents of the dihydropyridine ring at positions 3 and 5 have synperiplanar (cis) or antiperiplanar (trans) conformations with respect to the adjacent C=C bonds in the dihydropyridine ring. The 2,4-dichlorophenyl ring is almost planar [r.m.s. deviation = 0.0045 (1) Å] and almost perpendicular [89.27 (3)°] to the mean plane of the dihydropyridine ring. In the crystal, an N—H⋯O hydrogen bond links molecules into a zigzag chain along the ac diagonal. C—H⋯Cl contacts form centrosymmetric dimers and additional weak C—H⋯O contacts further consolidate the packing.

Related literature

For background to the pharmaceutical applications of 1,4-dihydropyridine derivatives, see: Rose (1989 ▶, 1990 ▶); Salehi & Guo (2004 ▶). For structure–activity relationships among 1,4-dihydropyridines, see: Triggle et al. (1980 ▶); Janis & Triggle (1984 ▶); Langs & Triggle (1985 ▶).

Experimental

Crystal data

C₁₇H₁₇Cl₂NO₂
M _r = 338.22
Monoclinic,
a = 10.307 (4) Å
b = 13.745 (3) Å
c = 11.312 (2) Å
β = 93.80 (2)°
V = 1599.0 (8) Å³
Z = 4
Mo Kα radiation
μ = 0.41 mm⁻¹
T = 293 K
0.23 × 0.21 × 0.18 mm

Data collection

Nonius MACH3 diffractometer
Absorption correction: ψ scan (North et al., 1968 ▶) T _min = 0.910, T _max = 0.929
3247 measured reflections
2811 independent reflections
2265 reflections with I > 2σ(I)
R _int = 0.014
3 standard reflections every 60 min intensity decay: none

Refinement

R[F ² > 2σ(F ²)] = 0.032
wR(F ²) = 0.096
S = 1.05
2811 reflections
207 parameters
H atoms treated by a mixture of independent and constrained refinement
Δρ_max = 0.21 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: CAD-4 EXPRESS (Enraf–Nonius, 1994 ▶); cell refinement: CAD-4 EXPRESS; data reduction: XCAD4 (Harms & Wocadlo, 1996 ▶); 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

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810052839/sj5076sup1.cif

e-67-0o380-sup1.cif^{(19.8KB, cif)}

Structure factors: contains datablocks I. DOI: 10.1107/S1600536810052839/sj5076Isup2.hkl

e-67-0o380-Isup2.hkl^{(138KB, hkl)}

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⋯O1ⁱ	0.81 (2)	2.16 (2)	2.951 (2)	163 (2)
C8—H8B⋯O2ⁱⁱ	0.96	2.56	3.397 (3)	147
C10—H10C⋯O2ⁱⁱ	0.96	2.43	3.341 (3)	158
C17—H17⋯Cl2ⁱⁱⁱ	0.93 (1)	2.92 (1)	3.796 (2)	158 (1)

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

Acknowledgments

JK thanks the UGC for the RFSMS fellowship. SN thanks the CSIR for funding provided under the Emeritus Scientist Scheme. VV is grateful to the DST–India for funding through the Young Scientist Scheme (Fast Track Proposal).

supplementary crystallographic information

Comment

1,4-Dihydropyridine derivatives have yielded many drugs which act as calcium channel agonists or antagonists (Rose, 1989, 1990) and various bioactive compounds such as vasodilator, antiatherosclerotic, antitumor, geroprotective, heptaprotective and antidiabetic agents (Salehi & Guo, 2004). Triggle and co-workers (Triggle et al., 1980; Janis & Triggle, 1984; Langs & Triggle, 1985) have identified some important structural requirements for biological activity. We have studied the crystal structure of 1,1'-[4-(2,4-dichlorophenyl)-2,6-dimethyl-1,4-dihydropyridine- 3,5-diyl]diethanone.

In the title compound (I)(Fig. 1), C₁₇H₁₇Cl₂NO₂, the central 1, 4-dihydropyridine ring adopts a flattened boat conformation. The ethanone substituents of the dihydropyridine ring at positions 3 and 5 have different (cis/trans) configurations with respect to the double bonds in the pyridine ring. Each group is oriented in a synperiplanar (cis) or antiperiplanar (trans) conformation with respect to the adjacent C═ C in the dihydropyridine ring, which is evident from the torsion angles of C6—C5—C11—O2 [31.44 (40)°] and C2—C3—C9—O1 [172.43 (20)°], respectively.

The methyl groups attached at C2 and C6 positions of the pyridine ring adopt equatorial orientation as can be seen from the torsion angles [C7—C6—N1—C2] 165.54 (20)° and [C8—C2—N1—C6] -164.62 (20)°. The 2,4-dichlorophenyl ring is planar and almost perpendicular to the mean plane of the dihydropyridine ring with the plane angle: 89.27 (3)°. This close to perpendicular orientation of the dichlorophenyl ring to the dihydropyridine ring can be ascribed to the greater steric hinderance with the two ethanone groups at C3 and C5. Atom N1(x,y,z) of the pyridine ring make a intermolecular hydrogen bond with the atom O1(-1/2 + x, 1/2 + y, -1/2 + z), leading to a zigzag chain running along the diagonal of the ac - plane (Fig. 2). C17—H17···Cl2 contacts form centrosymmetric dimers and additional weak C—H···O contacts further stabilise the structure, Table 1.

Experimental

2,4,dicholrobenzaldehyde (10 mmol), acetylacetone (20 mmol) and ammonium acetate (10 mmol) in ethanol were heated on a steam bath until the color of the solution changed to reddish-orange. The mixture was cooled in ice to yield a solid product, which was extracted using diethylether. The purity of the crude product was checked through TLC and recrystallized from acetone/ether 1:1 [yield: 60%, m.p. 218–220°C].