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Acta Crystallogr Sect E Struct Rep Online. 2009 September 1; 65(Pt 9): o2247–o2248.
Published online 2009 August 26. doi:  10.1107/S160053680903339X
PMCID: PMC2969936

Diethyl 4-(4-ethoxy­phen­yl)-2,6-dimethyl-1,4-dihydro­pyridine-3,5-dicarboxyl­ate

Abstract

In the title compound, C21H27NO5, the dihydropyridine ring adopts a boat conformation. The ethoxy­phenyl ring is oriented approximately perpendicular to the planar part of the dihydropyridine ring, making a dihedral angle of 89.45 (6)°. An intra­molecular C—H(...)O hydrogen bond generates an S(6) ring motif. In the crystal structure, neighbouring mol­ecules are linked into chains along the a axis by N—H(...)O hydrogen bonds and the chains are inter­connected into two-dimensional networks parallel to the ab plane by C—H(...)O hydrogen bonds. The structure is further stabilized by weak C—H(...)π inter­actions.

Related literature

For general background to and applications of 1,4-dihydro­pyridine derivatives, see: Böcker & Guengerich (1986 [triangle]); Cooper et al. (1992 [triangle]); Vo et al. (1995 [triangle]); Gaudio et al. (1994 [triangle]); Gordeev et al. (1996 [triangle]); Sunkel et al. (1992 [triangle]). For ring conformations and ring puckering analysis, see: Boeyens (1978 [triangle]); Cremer & Pople (1975 [triangle]). For hydrogen-bond motifs, see: Bernstein et al. (1995 [triangle]). For bond-length data, see: Allen et al. (1987 [triangle]). For a related structure, see: Thenmozhi et al. (2009 [triangle]). For the stability of the temperature controller used for the data collection, see: Cosier & Glazer (1986 [triangle]).

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Object name is e-65-o2247-scheme1.jpg

Experimental

Crystal data

  • C21H27NO5
  • M r = 373.44
  • Triclinic, An external file that holds a picture, illustration, etc.
Object name is e-65-o2247-efi1.jpg
  • a = 7.5557 (1) Å
  • b = 9.5697 (1) Å
  • c = 14.0553 (2) Å
  • α = 85.844 (1)°
  • β = 87.679 (1)°
  • γ = 81.458 (1)°
  • V = 1001.91 (2) Å3
  • Z = 2
  • Mo Kα radiation
  • μ = 0.09 mm−1
  • T = 296 K
  • 0.28 × 0.27 × 0.07 mm

Data collection

  • Bruker SMART APEXII CCD area-detector diffractometer
  • Absorption correction: multi-scan (SADABS; Bruker, 2005 [triangle]) T min = 0.976, T max = 0.994
  • 20664 measured reflections
  • 5290 independent reflections
  • 3602 reflections with I > 2σ(I)
  • R int = 0.027

Refinement

  • R[F 2 > 2σ(F 2)] = 0.055
  • wR(F 2) = 0.161
  • S = 1.02
  • 5290 reflections
  • 253 parameters
  • H atoms treated by a mixture of independent and constrained refinement
  • Δρmax = 0.32 e Å−3
  • Δρmin = −0.24 e Å−3

Data collection: APEX2 (Bruker, 2005 [triangle]); cell refinement: SAINT (Bruker, 2005 [triangle]); data reduction: SAINT; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 [triangle]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL and PLATON (Spek, 2009 [triangle]).

Table 1
Hydrogen-bond geometry (Å, °)

Supplementary Material

Crystal structure: contains datablocks global, I. DOI: 10.1107/S160053680903339X/ci2893sup1.cif

Structure factors: contains datablocks I. DOI: 10.1107/S160053680903339X/ci2893Isup2.hkl

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

Acknowledgments

HKF and JHG thank Universiti Sains Malaysia (USM) for the Research University Golden Goose grant (No. 1001/PFIZIK/811012). JHG also thanks USM for the award of a USM fellowship. VV is grateful to DST–India for funding through the Young Scientist Scheme (Fast Track Proposal).

supplementary crystallographic information

Comment

Hantzsch 1,4-dihydropyridines (1,4-DHPS) are biologically active compounds which includes various vasodilator, anti-hypertensive, bronchodilator, heptaprotective, anti-tumor, anti-mutagenic, geroprotective and anti-diabetic agents (Gaudio et al., 1994). Nifedipine, nitrendipine and nimodipine have found commercial utility as calcium channel blockers (Böcker et al., 1986; Gordeev et al., 1996). For the treatment of congestive heart failure, a number of DHP calcium antagonists have been introduced (Sunkel et al., 1992; Vo et al., 1995). Some of DHPs have been introduced as a neuroprotectant and cognition enhancer. In addition, a number of DHPs with platelet anti-aggregatory activity have also been discovered (Cooper et al., 1992).

In the title compound (Fig. 1), the dihydropyridine ring adopts a boat conformation (Boeyens, 1978; Cremer & Pople, 1975) with puckering amplitude Q = 0.2994 (16) Å, θ = 73.0 (3)° and [var phi] = 181.7 (3)°. Atoms C7 and N1 deviate from the C8/C9/C10/C11 plane by 0.362 (2) and 0.143 (2) Å, respectively. The C1-C6 benzene ring is perpendicular to the C8-C11 plane, making a dihedral angle of 89.45 (6)°. An intramolecular C20—H20A···O3 hydrogen bond generates an S(6) ring motif (Bernstein et al., 1995). Bond lengths (Allen et al., 1987) and angles are comparable to a related structure (Thenmozhi et al., 2009).

In the crystal structure (Fig. 2), neighbouring molecules are linked into chains along the a-axis by N1—H1N1···O2 hydrogen bonds (Table 1). These chains are interconnected into two-dimensional networks parallel to the ab plane by C12—H12A···O4 hydrogen bonds. The crystal structure is further stabilized by weak C16—H16A···Cg1 interactions (Table 1).

Experimental

The title compound was prepared according to Hantzsch pyridine synthesis. A mixture of 4-ethoxybenzaldehyde (10 mmol), ethylacetoacetate (20 mmol) and ammonium acetate (10 mmol) were heated at 353 K for 3 h (monitored by TLC). After completion of the reaction, the mixture was cooled to room temperature and kept for 2 days to get the solid product. The solid formed was washed using diethyl ether. After washing, the solid and the liquid was collected separately and the liquid was kept for solidification. The purity of the crude product was checked through TLC and recrystallized using acetone and ether (m.p. 377–379 K).

Refinement

Atom H1N1 was located from a difference Fourier map and allowed to refine freely. The other H-atoms were placed in calculated positions, with C-H = 0.93 Å, and Uiso = 1.2Ueq(C) for aromatic, and C-H = 0.96 Å and Uiso = 1.5Ueq(C) for methyl group. A rotating group model was used for the methyl group.

Figures

Fig. 1.
The molecular structure of the title compound, showing 25% probability displacement ellipsoids and the atom-numbering scheme. Hydrogen atoms are shown as spheres of arbitrary radius.
Fig. 2.
Two-dimensional network parallel to the ab plane, viewed along the c axis. Intermolecular hydrogen bonds are shown as dashed lines.

Crystal data

C21H27NO5Z = 2
Mr = 373.44F(000) = 400
Triclinic, P1Dx = 1.238 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.5557 (1) ÅCell parameters from 5893 reflections
b = 9.5697 (1) Åθ = 2.5–30.2°
c = 14.0553 (2) ŵ = 0.09 mm1
α = 85.844 (1)°T = 296 K
β = 87.679 (1)°Plate, colourless
γ = 81.458 (1)°0.28 × 0.27 × 0.07 mm
V = 1001.91 (2) Å3

Data collection

Bruker SMART APEXII CCD area-detector diffractometer5290 independent reflections
Radiation source: fine-focus sealed tube3602 reflections with I > 2σ(I)
graphiteRint = 0.027
[var phi] and ω scansθmax = 29.0°, θmin = 2.2°
Absorption correction: multi-scan (SADABS; Bruker, 2005)h = −10→10
Tmin = 0.976, Tmax = 0.994k = −11→13
20664 measured reflectionsl = −19→19

Refinement

Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.055Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.161H atoms treated by a mixture of independent and constrained refinement
S = 1.02w = 1/[σ2(Fo2) + (0.0714P)2 + 0.3075P] where P = (Fo2 + 2Fc2)/3
5290 reflections(Δ/σ)max = 0.001
253 parametersΔρmax = 0.32 e Å3
0 restraintsΔρmin = −0.24 e Å3

Special details

Experimental. The crystal was placed in the cold stream of an Oxford Cyrosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1)K.
Geometry. All esds (except the esd in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell esds are taken into account individually in the estimation of esds in distances, angles and torsion angles; correlations between esds in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell esds is used for estimating esds involving l.s. planes.
Refinement. Refinement of F2 against ALL reflections. The weighted R-factor wR and goodness of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. The threshold expression of F2 > 2sigma(F2) is used only for calculating R-factors(gt) etc. and is not relevant to the choice of reflections for refinement. R-factors based on F2 are statistically about twice as large as those based on F, and R- factors based on ALL data will be even larger.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2)

xyzUiso*/Ueq
O10.73624 (18)0.59395 (15)0.53338 (9)0.0547 (4)
O21.01269 (16)0.23542 (17)0.96209 (10)0.0603 (4)
O30.81388 (15)0.34092 (15)1.06441 (9)0.0511 (3)
O40.5806 (2)−0.10910 (17)0.71435 (11)0.0672 (4)
O50.85133 (17)−0.04519 (14)0.72123 (9)0.0525 (3)
N10.41011 (18)0.18714 (16)0.92272 (10)0.0402 (3)
C10.8807 (2)0.28106 (19)0.68730 (11)0.0416 (4)
H1A0.97200.20430.68700.050*
C20.8726 (2)0.3840 (2)0.61279 (12)0.0452 (4)
H2A0.95830.37610.56330.054*
C30.7373 (2)0.49899 (19)0.61149 (11)0.0412 (4)
C40.6152 (2)0.5125 (2)0.68730 (13)0.0479 (4)
H4A0.52670.59110.68860.058*
C50.6254 (2)0.40778 (19)0.76151 (12)0.0431 (4)
H5A0.54210.41750.81200.052*
C60.7553 (2)0.28953 (17)0.76285 (10)0.0333 (3)
C70.7547 (2)0.16927 (17)0.84131 (10)0.0328 (3)
H7A0.87500.11440.84340.039*
C80.7073 (2)0.22640 (17)0.93892 (10)0.0330 (3)
C90.5348 (2)0.24150 (17)0.97270 (10)0.0347 (3)
C100.4537 (2)0.09203 (17)0.85327 (11)0.0373 (4)
C110.6234 (2)0.07125 (17)0.81710 (10)0.0352 (3)
C120.5781 (3)0.6937 (2)0.51790 (14)0.0552 (5)
H12A0.55850.75720.56920.066*
H12B0.47480.64470.51590.066*
C130.6041 (4)0.7752 (3)0.42475 (17)0.0825 (8)
H13A0.49900.84270.41200.124*
H13B0.62420.71120.37460.124*
H13C0.70560.82410.42780.124*
C140.8579 (2)0.26575 (18)0.98833 (11)0.0365 (4)
C150.9594 (2)0.3755 (2)1.11817 (13)0.0532 (5)
H15A1.03880.42481.07650.064*
H15B1.02800.28971.14610.064*
C160.8798 (3)0.4675 (3)1.19452 (16)0.0695 (6)
H16A0.97300.48741.23360.104*
H16B0.79640.41981.23310.104*
H16C0.81850.55461.16600.104*
C170.6761 (2)−0.03516 (18)0.74743 (11)0.0411 (4)
C180.9092 (3)−0.1407 (3)0.64637 (16)0.0676 (6)
H18A0.8361−0.11440.59090.081*
H18B0.8960−0.23700.66870.081*
C191.0976 (4)−0.1317 (4)0.6207 (2)0.1091 (12)
H19A1.1366−0.19320.57060.164*
H19B1.1694−0.16010.67550.164*
H19C1.1098−0.03600.59930.164*
C200.4542 (2)0.3115 (2)1.05970 (12)0.0461 (4)
H20A0.54520.31021.10560.069*
H20B0.36130.26141.08700.069*
H20C0.40460.40781.04210.069*
C210.2974 (2)0.0239 (2)0.82690 (14)0.0506 (5)
H21A0.3381−0.07250.81300.076*
H21B0.24270.07480.77170.076*
H21C0.21140.02610.87920.076*
H1N10.303 (3)0.200 (2)0.9447 (15)0.063 (6)*

Atomic displacement parameters (Å2)

U11U22U33U12U13U23
O10.0620 (8)0.0562 (8)0.0433 (7)−0.0086 (7)0.0050 (6)0.0103 (6)
O20.0287 (6)0.0946 (11)0.0613 (8)−0.0088 (6)0.0039 (5)−0.0333 (8)
O30.0326 (6)0.0773 (9)0.0471 (7)−0.0096 (6)−0.0008 (5)−0.0263 (6)
O40.0660 (9)0.0695 (10)0.0748 (10)−0.0262 (8)0.0099 (7)−0.0365 (8)
O50.0489 (7)0.0514 (8)0.0592 (8)−0.0065 (6)0.0092 (6)−0.0238 (6)
N10.0265 (7)0.0497 (9)0.0451 (8)−0.0061 (6)0.0012 (5)−0.0090 (6)
C10.0363 (8)0.0457 (10)0.0419 (8)−0.0037 (7)0.0077 (7)−0.0057 (7)
C20.0461 (10)0.0515 (11)0.0379 (8)−0.0093 (8)0.0135 (7)−0.0056 (7)
C30.0469 (9)0.0434 (10)0.0352 (8)−0.0143 (8)0.0019 (7)−0.0016 (7)
C40.0484 (10)0.0450 (10)0.0464 (9)0.0020 (8)0.0080 (8)0.0000 (8)
C50.0427 (9)0.0446 (10)0.0394 (8)−0.0015 (7)0.0118 (7)−0.0024 (7)
C60.0320 (7)0.0376 (8)0.0321 (7)−0.0090 (6)0.0020 (6)−0.0075 (6)
C70.0282 (7)0.0370 (8)0.0326 (7)−0.0019 (6)0.0023 (5)−0.0058 (6)
C80.0289 (7)0.0381 (8)0.0318 (7)−0.0037 (6)0.0001 (5)−0.0035 (6)
C90.0304 (7)0.0394 (9)0.0340 (7)−0.0040 (6)−0.0003 (6)−0.0020 (6)
C100.0350 (8)0.0365 (9)0.0407 (8)−0.0058 (7)−0.0051 (6)−0.0015 (7)
C110.0373 (8)0.0347 (8)0.0333 (7)−0.0046 (6)−0.0018 (6)−0.0016 (6)
C120.0630 (12)0.0531 (12)0.0514 (10)−0.0148 (10)−0.0137 (9)0.0034 (9)
C130.108 (2)0.0797 (17)0.0598 (13)−0.0203 (15)−0.0214 (13)0.0220 (12)
C140.0313 (8)0.0452 (9)0.0334 (7)−0.0064 (7)0.0008 (6)−0.0042 (6)
C150.0381 (9)0.0764 (14)0.0486 (10)−0.0115 (9)−0.0083 (7)−0.0171 (9)
C160.0631 (13)0.0843 (17)0.0649 (13)−0.0092 (12)−0.0098 (10)−0.0308 (12)
C170.0466 (9)0.0382 (9)0.0387 (8)−0.0076 (7)0.0001 (7)−0.0028 (7)
C180.0696 (14)0.0679 (15)0.0687 (13)−0.0092 (11)0.0135 (11)−0.0369 (11)
C190.0758 (18)0.135 (3)0.128 (3)−0.0290 (18)0.0381 (17)−0.086 (2)
C200.0338 (8)0.0614 (12)0.0430 (9)−0.0055 (8)0.0073 (7)−0.0116 (8)
C210.0377 (9)0.0557 (12)0.0617 (11)−0.0132 (8)−0.0060 (8)−0.0110 (9)

Geometric parameters (Å, °)

O1—C31.373 (2)C10—C111.352 (2)
O1—C121.428 (2)C10—C211.502 (2)
O2—C141.2115 (18)C11—C171.465 (2)
O3—C141.3353 (19)C12—C131.496 (3)
O3—C151.450 (2)C12—H12A0.97
O4—C171.210 (2)C12—H12B0.97
O5—C171.351 (2)C13—H13A0.96
O5—C181.455 (2)C13—H13B0.96
N1—C101.380 (2)C13—H13C0.96
N1—C91.380 (2)C15—C161.488 (3)
N1—H1N10.85 (2)C15—H15A0.97
C1—C21.382 (2)C15—H15B0.97
C1—C61.393 (2)C16—H16A0.96
C1—H1A0.93C16—H16B0.96
C2—C31.386 (3)C16—H16C0.96
C2—H2A0.93C18—C191.467 (3)
C3—C41.382 (2)C18—H18A0.97
C4—C51.389 (2)C18—H18B0.97
C4—H4A0.93C19—H19A0.96
C5—C61.383 (2)C19—H19B0.96
C5—H5A0.93C19—H19C0.96
C6—C71.535 (2)C20—H20A0.96
C7—C81.523 (2)C20—H20B0.96
C7—C111.527 (2)C20—H20C0.96
C7—H7A0.98C21—H21A0.96
C8—C91.360 (2)C21—H21B0.96
C8—C141.466 (2)C21—H21C0.96
C9—C201.501 (2)
C3—O1—C12117.87 (14)C12—C13—H13A109.5
C14—O3—C15117.18 (13)C12—C13—H13B109.5
C17—O5—C18115.21 (15)H13A—C13—H13B109.5
C10—N1—C9123.89 (13)C12—C13—H13C109.5
C10—N1—H1N1118.1 (15)H13A—C13—H13C109.5
C9—N1—H1N1116.6 (15)H13B—C13—H13C109.5
C2—C1—C6121.53 (16)O2—C14—O3121.24 (15)
C2—C1—H1A119.2O2—C14—C8123.23 (14)
C6—C1—H1A119.2O3—C14—C8115.52 (13)
C1—C2—C3120.26 (15)O3—C15—C16107.77 (15)
C1—C2—H2A119.9O3—C15—H15A110.2
C3—C2—H2A119.9C16—C15—H15A110.2
O1—C3—C4124.29 (16)O3—C15—H15B110.2
O1—C3—C2116.40 (14)C16—C15—H15B110.2
C4—C3—C2119.31 (15)H15A—C15—H15B108.5
C3—C4—C5119.52 (16)C15—C16—H16A109.5
C3—C4—H4A120.2C15—C16—H16B109.5
C5—C4—H4A120.2H16A—C16—H16B109.5
C6—C5—C4122.26 (15)C15—C16—H16C109.5
C6—C5—H5A118.9H16A—C16—H16C109.5
C4—C5—H5A118.9H16B—C16—H16C109.5
C5—C6—C1117.05 (15)O4—C17—O5120.80 (16)
C5—C6—C7121.32 (13)O4—C17—C11126.77 (16)
C1—C6—C7121.55 (14)O5—C17—C11112.43 (14)
C8—C7—C11110.43 (12)O5—C18—C19108.76 (19)
C8—C7—C6111.55 (12)O5—C18—H18A109.9
C11—C7—C6109.65 (12)C19—C18—H18A109.9
C8—C7—H7A108.4O5—C18—H18B109.9
C11—C7—H7A108.4C19—C18—H18B109.9
C6—C7—H7A108.4H18A—C18—H18B108.3
C9—C8—C14124.96 (14)C18—C19—H19A109.5
C9—C8—C7120.06 (13)C18—C19—H19B109.5
C14—C8—C7114.94 (12)H19A—C19—H19B109.5
C8—C9—N1118.44 (14)C18—C19—H19C109.5
C8—C9—C20129.12 (15)H19A—C19—H19C109.5
N1—C9—C20112.44 (13)H19B—C19—H19C109.5
C11—C10—N1119.10 (15)C9—C20—H20A109.5
C11—C10—C21128.03 (15)C9—C20—H20B109.5
N1—C10—C21112.87 (14)H20A—C20—H20B109.5
C10—C11—C17120.26 (15)C9—C20—H20C109.5
C10—C11—C7119.61 (14)H20A—C20—H20C109.5
C17—C11—C7119.84 (13)H20B—C20—H20C109.5
O1—C12—C13107.53 (18)C10—C21—H21A109.5
O1—C12—H12A110.2C10—C21—H21B109.5
C13—C12—H12A110.2H21A—C21—H21B109.5
O1—C12—H12B110.2C10—C21—H21C109.5
C13—C12—H12B110.2H21A—C21—H21C109.5
H12A—C12—H12B108.5H21B—C21—H21C109.5
C6—C1—C2—C3−0.3 (3)C9—N1—C10—C11−14.2 (2)
C12—O1—C3—C4−15.4 (3)C9—N1—C10—C21166.34 (16)
C12—O1—C3—C2165.31 (16)N1—C10—C11—C17176.38 (14)
C1—C2—C3—O1−178.08 (16)C21—C10—C11—C17−4.2 (3)
C1—C2—C3—C42.6 (3)N1—C10—C11—C7−9.8 (2)
O1—C3—C4—C5178.09 (17)C21—C10—C11—C7169.58 (16)
C2—C3—C4—C5−2.7 (3)C8—C7—C11—C1029.0 (2)
C3—C4—C5—C60.4 (3)C6—C7—C11—C10−94.32 (16)
C4—C5—C6—C11.9 (3)C8—C7—C11—C17−157.19 (13)
C4—C5—C6—C7−174.85 (16)C6—C7—C11—C1779.49 (17)
C2—C1—C6—C5−1.9 (3)C3—O1—C12—C13−174.91 (18)
C2—C1—C6—C7174.78 (16)C15—O3—C14—O2−4.4 (3)
C5—C6—C7—C8−40.9 (2)C15—O3—C14—C8176.84 (15)
C1—C6—C7—C8142.47 (15)C9—C8—C14—O2170.76 (18)
C5—C6—C7—C1181.70 (18)C7—C8—C14—O2−11.3 (2)
C1—C6—C7—C11−94.88 (17)C9—C8—C14—O3−10.5 (2)
C11—C7—C8—C9−28.3 (2)C7—C8—C14—O3167.43 (14)
C6—C7—C8—C993.93 (17)C14—O3—C15—C16175.95 (18)
C11—C7—C8—C14153.64 (13)C18—O5—C17—O44.9 (3)
C6—C7—C8—C14−84.16 (16)C18—O5—C17—C11−175.20 (16)
C14—C8—C9—N1−173.78 (15)C10—C11—C17—O42.0 (3)
C7—C8—C9—N18.3 (2)C7—C11—C17—O4−171.78 (17)
C14—C8—C9—C206.4 (3)C10—C11—C17—O5−177.96 (15)
C7—C8—C9—C20−171.48 (16)C7—C11—C17—O58.3 (2)
C10—N1—C9—C814.9 (2)C17—O5—C18—C19175.6 (2)
C10—N1—C9—C20−165.23 (15)

Hydrogen-bond geometry (Å, °)

D—H···AD—HH···AD···AD—H···A
N1—H1N1···O2i0.85 (2)2.18 (2)3.0045 (19)165 (2)
C12—H12A···O4ii0.972.513.458 (2)166
C20—H20A···O30.962.142.7774 (19)122
C16—H16A···Cg1iii0.962.833.767 (2)165

Symmetry codes: (i) x−1, y, z; (ii) x, y+1, z; (iii) −x+2, −y+1, −z+2.

Footnotes

Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: CI2893).

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