organic compounds
Dimethyl 4-(4-formylphenyl)-2,6-dimethyl-1,4-dihydropyridine-3,5-dicarboxylate
aDepartment of Chemistry, Shandong Normal University, Jinan 250014, People's Republic of China
*Correspondence e-mail: liuqj@sdnu.edu.cn
The title compound, C18H19NO5, is a product of the Hantzsch reaction of p-phthalaldehyde, methyl acetoacetate, and ammonium acetate. The 1,4-dihydropyridine ring of the molecule adopts a flattened boat conformation. The benzene ring is almost perpendicular to the 1,4-dihydropyridine ring; the plane through the six C atoms of the benzene ring and the plane through the four C atoms that form the base of the boat-shaped 1,4-dihydropyridine ring (excluding the ring N atom and the opposite ring C atom) make a dihedral angle of 87.60 (3)°. Intermolecular N—H⋯O hydrogen bonds result in the formation of extended chains along the a axis.
Related literature
For a related 1,4-dihydropyridine structure, see: Fossheim et al. (1982). For the synthesis of 1,4-dihydropyridines, see: Hantzsch & Liebigs (1882). For the biological activity of 1,4-dihydropyridines, see: Janis & Triggle (1983).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 2001); cell SAINT (Bruker, 2001); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 2001); software used to prepare material for publication: SHELXTL.
Supporting information
https://doi.org/10.1107/S1600536807063428/sq2008sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536807063428/sq2008Isup2.hkl
The title compound,(I), was prepared by refluxing a mixture of p-phthaldehyde (0.67 g, 5.0 mmol), methyl acetoacetate (1.19 g, 10.25 mmol), and ammonium acetate (0.58 g, 7.5 mmol) for 6 h in water (10 ml), and purified by recrystallization, m.p.479–481 K. Single crystals suitable for X-ray diffraction were obtained by slow evaporation of an ethyl acetate solution.
All non-hydrogen atoms were refined with anisotropic displacement parameters. Hydrogen atoms attached to anisotropically refined atoms were placed in geometrically idealized positions and included as riding atoms with C—H = 0.93Å and Uiso(H) = 1.2*Ueq(C) (aromatic); C—H = 0.96Å and Uiso(H) = 1.5*Ueq(C) (methyl); C—H = 0.98Å and Uiso(H) = 1.2*Ueq(C) (tertiary CH).
It is well known that 1,4-dihydropyridines (DHPs) exhibit a wide range of biological activities, acting as potent vasodilators and antihypertensives (Janis & Triggle, 1983). The classical preparation method of 1,4-dihydropyridines is the Hantzsch reaction (Hantzsch & Liebigs, 1882). We have synthesized a series of 1,4-dihydropyridine compounds by the Hantzsch protocol in water. The structure of (I) was fully characterized by NMR (1H,13C), MS, IR, and elemental analysis and was confirmed by single-crystal X-ray crystallographic analysis (Figure 1).
The bond lengths and angles in (I) show normal values (Table 1) except for the geometry of the 1,4-dihydropyridine ring which adopts a flattened boat conformation with ring distortions at the nitrogen (Nl) and the tetrahedral carbon (C11). Both atoms are displaced to the same side of the ring with distances of 0.17Å and 0.39 Å, respectively, from the plane defined by C3, C4, C7, and C8, and thus form the apices of a boat-type conformation (Fossheim et al., 1982). The phenyl ring is almost perpendicular to the 1,4-dihydropyridine ring (N1—C4—C3—C11—C8—C7) with a dihedral angle of 92.40 (1)°. The bisect plane of the 1,4-dihydropyridine ring defined by N1, C11, and C12 makes a dihedral angle of 35.40 (7)° with the phenyl ring. The intermolecular hydrogen bonds N1—H1···O5i [symmetry code (i): -x + 1, -y + 2, -z + 2] between the pyridine N atom and a neighboring formyl O atom result in the formation of extended chains along the a axis (Figure 2).
For a related 1,4-dihydropyridine structure, see: Fossheim et al. (1982). For the synthesis of 1,4-dihydropyridines, see: Hantzsch & Liebigs (1882). For the biological activity of 1,4-dihydropyridines, see: Janis & Triggle (1983).
Data collection: SMART (Bruker, 2001); cell
SMART (Bruker, 2001); data reduction: SAINT (Bruker, 2001); program(s) used to solve structure: SHELXS97 (Sheldrick, 1990); program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: SHELXTL (Sheldrick, 2001); software used to prepare material for publication: SHELXTL (Sheldrick, 2001).C18H19NO5 | Z = 2 |
Mr = 329.34 | F(000) = 348 |
Triclinic, P1 | Dx = 1.342 Mg m−3 |
Hall symbol: -P 1 | Melting point: 479 K |
a = 8.219 (2) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 10.432 (3) Å | Cell parameters from 1572 reflections |
c = 10.979 (3) Å | θ = 2.2–26.7° |
α = 111.364 (3)° | µ = 0.10 mm−1 |
β = 102.799 (3)° | T = 298 K |
γ = 101.150 (4)° | Plate, colourless |
V = 815.0 (4) Å3 | 0.48 × 0.34 × 0.10 mm |
Bruker SMART CCD area-detector diffractometer | 2855 independent reflections |
Radiation source: fine-focus sealed tube | 2352 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.015 |
phi and ω scans | θmax = 25.1°, θmin = 2.1° |
Absorption correction: multi-scan (SADABS: Sheldrick, 2004) | h = −7→9 |
Tmin = 0.954, Tmax = 0.990 | k = −12→12 |
4173 measured reflections | l = −13→11 |
Refinement on F2 | Primary atom site location: structure-invariant direct methods |
Least-squares matrix: full | Secondary atom site location: difference Fourier map |
R[F2 > 2σ(F2)] = 0.052 | Hydrogen site location: inferred from neighbouring sites |
wR(F2) = 0.140 | H-atom parameters constrained |
S = 1.04 | w = 1/[σ2(Fo2) + (0.0745P)2 + 0.2263P] where P = (Fo2 + 2Fc2)/3 |
2855 reflections | (Δ/σ)max < 0.001 |
221 parameters | Δρmax = 0.25 e Å−3 |
0 restraints | Δρmin = −0.23 e Å−3 |
C18H19NO5 | γ = 101.150 (4)° |
Mr = 329.34 | V = 815.0 (4) Å3 |
Triclinic, P1 | Z = 2 |
a = 8.219 (2) Å | Mo Kα radiation |
b = 10.432 (3) Å | µ = 0.10 mm−1 |
c = 10.979 (3) Å | T = 298 K |
α = 111.364 (3)° | 0.48 × 0.34 × 0.10 mm |
β = 102.799 (3)° |
Bruker SMART CCD area-detector diffractometer | 2855 independent reflections |
Absorption correction: multi-scan (SADABS: Sheldrick, 2004) | 2352 reflections with I > 2σ(I) |
Tmin = 0.954, Tmax = 0.990 | Rint = 0.015 |
4173 measured reflections |
R[F2 > 2σ(F2)] = 0.052 | 0 restraints |
wR(F2) = 0.140 | H-atom parameters constrained |
S = 1.04 | Δρmax = 0.25 e Å−3 |
2855 reflections | Δρmin = −0.23 e Å−3 |
221 parameters |
Geometry. All e.s.d.'s (except the e.s.d. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell e.s.d.'s are taken into account individually in the estimation of e.s.d.'s in distances, angles and torsion angles; correlations between e.s.d.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell e.s.d.'s is used for estimating e.s.d.'s 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 > σ(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. |
x | y | z | Uiso*/Ueq | ||
C1 | 0.0487 (3) | 0.7111 (3) | 0.2379 (2) | 0.0540 (6) | |
H1A | 0.1663 | 0.7527 | 0.2429 | 0.081* | |
H1B | −0.0263 | 0.7598 | 0.2053 | 0.081* | |
H1C | 0.0087 | 0.6105 | 0.1753 | 0.081* | |
C2 | 0.1597 (3) | 0.6835 (2) | 0.4429 (2) | 0.0369 (5) | |
C3 | 0.1430 (2) | 0.7146 (2) | 0.58051 (19) | 0.0316 (4) | |
C4 | 0.2082 (3) | 0.6488 (2) | 0.6575 (2) | 0.0360 (5) | |
C5 | 0.3136 (3) | 0.5473 (2) | 0.6249 (3) | 0.0501 (6) | |
H5A | 0.2939 | 0.5048 | 0.5272 | 0.075* | |
H5B | 0.2792 | 0.4727 | 0.6538 | 0.075* | |
H5C | 0.4355 | 0.5989 | 0.6725 | 0.075* | |
C6 | −0.0172 (3) | 0.7028 (3) | 0.9224 (3) | 0.0562 (6) | |
H6A | −0.0266 | 0.7913 | 0.9853 | 0.084* | |
H6B | 0.0693 | 0.6730 | 0.9707 | 0.084* | |
H6C | −0.1282 | 0.6294 | 0.8845 | 0.084* | |
C7 | 0.0357 (3) | 0.7258 (2) | 0.8083 (2) | 0.0369 (5) | |
C8 | −0.0337 (2) | 0.7922 (2) | 0.73481 (19) | 0.0326 (4) | |
C9 | −0.1879 (3) | 0.8380 (2) | 0.7515 (2) | 0.0403 (5) | |
C10 | −0.3909 (3) | 0.9447 (3) | 0.6724 (3) | 0.0648 (7) | |
H10A | −0.4883 | 0.8609 | 0.6436 | 0.097* | |
H10B | −0.4126 | 0.9901 | 0.6110 | 0.097* | |
H10C | −0.3759 | 1.0113 | 0.7646 | 0.097* | |
C11 | 0.0538 (2) | 0.8272 (2) | 0.63858 (18) | 0.0298 (4) | |
H11 | −0.0369 | 0.8235 | 0.5614 | 0.036* | |
C12 | 0.1873 (2) | 0.9776 (2) | 0.70850 (19) | 0.0306 (4) | |
C13 | 0.2279 (3) | 1.0506 (2) | 0.6300 (2) | 0.0352 (5) | |
H13 | 0.1695 | 1.0093 | 0.5356 | 0.042* | |
C14 | 0.3539 (3) | 1.1837 (2) | 0.6906 (2) | 0.0387 (5) | |
H14 | 0.3797 | 1.2310 | 0.6368 | 0.046* | |
C15 | 0.4421 (2) | 1.2473 (2) | 0.8316 (2) | 0.0360 (5) | |
C16 | 0.5802 (3) | 1.3855 (2) | 0.8933 (2) | 0.0443 (5) | |
H16 | 0.5943 | 1.4329 | 0.8374 | 0.053* | |
C17 | 0.4002 (3) | 1.1764 (2) | 0.9107 (2) | 0.0423 (5) | |
H17 | 0.4576 | 1.2186 | 1.0054 | 0.051* | |
C18 | 0.2739 (3) | 1.0439 (2) | 0.8499 (2) | 0.0395 (5) | |
H18 | 0.2461 | 0.9981 | 0.9044 | 0.047* | |
O1 | 0.2601 (3) | 0.6284 (2) | 0.39502 (18) | 0.0686 (5) | |
O2 | 0.0449 (2) | 0.72623 (17) | 0.37188 (14) | 0.0483 (4) | |
O3 | −0.23540 (19) | 0.90263 (18) | 0.66944 (17) | 0.0504 (4) | |
O4 | −0.2703 (2) | 0.8207 (2) | 0.8252 (2) | 0.0747 (6) | |
O5 | 0.6775 (2) | 1.44321 (17) | 1.01131 (17) | 0.0562 (5) | |
N1 | 0.1702 (2) | 0.67213 (19) | 0.77876 (18) | 0.0412 (4) | |
H1 | 0.2335 | 0.6523 | 0.8389 | 0.049* |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0704 (16) | 0.0601 (15) | 0.0303 (12) | 0.0144 (12) | 0.0190 (11) | 0.0191 (11) |
C2 | 0.0353 (10) | 0.0365 (11) | 0.0348 (11) | 0.0084 (9) | 0.0136 (9) | 0.0106 (9) |
C3 | 0.0284 (9) | 0.0344 (10) | 0.0300 (10) | 0.0073 (8) | 0.0094 (8) | 0.0126 (8) |
C4 | 0.0324 (10) | 0.0351 (10) | 0.0359 (11) | 0.0063 (8) | 0.0084 (8) | 0.0136 (9) |
C5 | 0.0477 (13) | 0.0487 (13) | 0.0603 (15) | 0.0223 (11) | 0.0167 (11) | 0.0264 (12) |
C6 | 0.0671 (16) | 0.0706 (16) | 0.0500 (14) | 0.0234 (13) | 0.0269 (12) | 0.0401 (13) |
C7 | 0.0367 (11) | 0.0396 (11) | 0.0322 (11) | 0.0063 (9) | 0.0105 (9) | 0.0158 (9) |
C8 | 0.0303 (10) | 0.0386 (11) | 0.0272 (10) | 0.0072 (8) | 0.0098 (8) | 0.0134 (8) |
C9 | 0.0353 (11) | 0.0498 (12) | 0.0351 (11) | 0.0104 (9) | 0.0154 (9) | 0.0162 (10) |
C10 | 0.0452 (14) | 0.0819 (19) | 0.088 (2) | 0.0365 (13) | 0.0322 (14) | 0.0428 (16) |
C11 | 0.0283 (9) | 0.0377 (10) | 0.0242 (9) | 0.0097 (8) | 0.0084 (8) | 0.0140 (8) |
C12 | 0.0305 (10) | 0.0353 (10) | 0.0307 (10) | 0.0144 (8) | 0.0129 (8) | 0.0151 (8) |
C13 | 0.0385 (11) | 0.0391 (11) | 0.0297 (10) | 0.0129 (9) | 0.0097 (8) | 0.0166 (9) |
C14 | 0.0419 (11) | 0.0422 (12) | 0.0427 (12) | 0.0157 (9) | 0.0182 (9) | 0.0255 (10) |
C15 | 0.0329 (10) | 0.0365 (11) | 0.0408 (11) | 0.0133 (8) | 0.0139 (9) | 0.0162 (9) |
C16 | 0.0418 (12) | 0.0413 (12) | 0.0522 (14) | 0.0134 (10) | 0.0155 (11) | 0.0219 (11) |
C17 | 0.0429 (12) | 0.0461 (12) | 0.0304 (11) | 0.0070 (9) | 0.0097 (9) | 0.0126 (9) |
C18 | 0.0436 (12) | 0.0438 (12) | 0.0301 (11) | 0.0060 (9) | 0.0127 (9) | 0.0177 (9) |
O1 | 0.0757 (12) | 0.0995 (15) | 0.0529 (11) | 0.0537 (12) | 0.0386 (10) | 0.0324 (10) |
O2 | 0.0566 (9) | 0.0688 (10) | 0.0300 (8) | 0.0290 (8) | 0.0194 (7) | 0.0240 (7) |
O3 | 0.0424 (9) | 0.0688 (11) | 0.0632 (11) | 0.0303 (8) | 0.0285 (8) | 0.0392 (9) |
O4 | 0.0658 (12) | 0.1291 (18) | 0.0740 (13) | 0.0490 (12) | 0.0508 (11) | 0.0651 (13) |
O5 | 0.0491 (9) | 0.0482 (9) | 0.0542 (11) | 0.0042 (8) | 0.0013 (8) | 0.0173 (8) |
N1 | 0.0425 (10) | 0.0499 (11) | 0.0385 (10) | 0.0177 (8) | 0.0100 (8) | 0.0266 (8) |
C1—O2 | 1.429 (2) | C9—O4 | 1.203 (2) |
C1—H1A | 0.9600 | C9—O3 | 1.344 (2) |
C1—H1B | 0.9600 | C10—O3 | 1.432 (3) |
C1—H1C | 0.9600 | C10—H10A | 0.9600 |
C2—O1 | 1.202 (2) | C10—H10B | 0.9600 |
C2—O2 | 1.337 (3) | C10—H10C | 0.9600 |
C2—C3 | 1.469 (3) | C11—C12 | 1.529 (3) |
C3—C4 | 1.355 (3) | C11—H11 | 0.9800 |
C3—C11 | 1.522 (3) | C12—C18 | 1.390 (3) |
C4—N1 | 1.381 (3) | C12—C13 | 1.394 (3) |
C4—C5 | 1.489 (3) | C13—C14 | 1.381 (3) |
C5—H5A | 0.9600 | C13—H13 | 0.9300 |
C5—H5B | 0.9600 | C14—C15 | 1.389 (3) |
C5—H5C | 0.9600 | C14—H14 | 0.9300 |
C6—C7 | 1.495 (3) | C15—C17 | 1.386 (3) |
C6—H6A | 0.9600 | C15—C16 | 1.463 (3) |
C6—H6B | 0.9600 | C16—O5 | 1.211 (3) |
C6—H6C | 0.9600 | C16—H16 | 0.9300 |
C7—C8 | 1.346 (3) | C17—C18 | 1.378 (3) |
C7—N1 | 1.381 (3) | C17—H17 | 0.9300 |
C8—C9 | 1.463 (3) | C18—H18 | 0.9300 |
C8—C11 | 1.511 (2) | N1—H1 | 0.8600 |
O2—C1—H1A | 109.5 | O3—C10—H10B | 109.5 |
O2—C1—H1B | 109.5 | H10A—C10—H10B | 109.5 |
H1A—C1—H1B | 109.5 | O3—C10—H10C | 109.5 |
O2—C1—H1C | 109.5 | H10A—C10—H10C | 109.5 |
H1A—C1—H1C | 109.5 | H10B—C10—H10C | 109.5 |
H1B—C1—H1C | 109.5 | C8—C11—C3 | 110.09 (15) |
O1—C2—O2 | 121.76 (19) | C8—C11—C12 | 112.69 (15) |
O1—C2—C3 | 127.5 (2) | C3—C11—C12 | 109.55 (15) |
O2—C2—C3 | 110.72 (16) | C8—C11—H11 | 108.1 |
C4—C3—C2 | 121.94 (18) | C3—C11—H11 | 108.1 |
C4—C3—C11 | 119.60 (17) | C12—C11—H11 | 108.1 |
C2—C3—C11 | 118.44 (16) | C18—C12—C13 | 118.16 (18) |
C3—C4—N1 | 118.15 (18) | C18—C12—C11 | 121.69 (16) |
C3—C4—C5 | 127.55 (19) | C13—C12—C11 | 120.14 (16) |
N1—C4—C5 | 114.27 (17) | C14—C13—C12 | 120.86 (18) |
C4—C5—H5A | 109.5 | C14—C13—H13 | 119.6 |
C4—C5—H5B | 109.5 | C12—C13—H13 | 119.6 |
H5A—C5—H5B | 109.5 | C13—C14—C15 | 120.34 (18) |
C4—C5—H5C | 109.5 | C13—C14—H14 | 119.8 |
H5A—C5—H5C | 109.5 | C15—C14—H14 | 119.8 |
H5B—C5—H5C | 109.5 | C17—C15—C14 | 119.14 (19) |
C7—C6—H6A | 109.5 | C17—C15—C16 | 121.20 (19) |
C7—C6—H6B | 109.5 | C14—C15—C16 | 119.65 (19) |
H6A—C6—H6B | 109.5 | O5—C16—C15 | 125.3 (2) |
C7—C6—H6C | 109.5 | O5—C16—H16 | 117.4 |
H6A—C6—H6C | 109.5 | C15—C16—H16 | 117.4 |
H6B—C6—H6C | 109.5 | C18—C17—C15 | 120.34 (19) |
C8—C7—N1 | 118.71 (17) | C18—C17—H17 | 119.8 |
C8—C7—C6 | 126.71 (19) | C15—C17—H17 | 119.8 |
N1—C7—C6 | 114.59 (18) | C17—C18—C12 | 121.13 (18) |
C7—C8—C9 | 121.16 (17) | C17—C18—H18 | 119.4 |
C7—C8—C11 | 119.69 (17) | C12—C18—H18 | 119.4 |
C9—C8—C11 | 119.07 (16) | C2—O2—C1 | 118.39 (17) |
O4—C9—O3 | 121.06 (19) | C9—O3—C10 | 116.16 (17) |
O4—C9—C8 | 127.2 (2) | C7—N1—C4 | 123.31 (16) |
O3—C9—C8 | 111.71 (16) | C7—N1—H1 | 118.3 |
O3—C10—H10A | 109.5 | C4—N1—H1 | 118.3 |
O1—C2—C3—C4 | −18.6 (3) | C8—C11—C12—C18 | 27.1 (2) |
O2—C2—C3—C4 | 161.80 (17) | C3—C11—C12—C18 | −95.8 (2) |
O1—C2—C3—C11 | 159.8 (2) | C8—C11—C12—C13 | −154.35 (17) |
O2—C2—C3—C11 | −19.8 (2) | C3—C11—C12—C13 | 82.7 (2) |
C2—C3—C4—N1 | −172.96 (17) | C18—C12—C13—C14 | 1.6 (3) |
C11—C3—C4—N1 | 8.7 (3) | C11—C12—C13—C14 | −177.05 (17) |
C2—C3—C4—C5 | 4.6 (3) | C12—C13—C14—C15 | −0.2 (3) |
C11—C3—C4—C5 | −173.75 (19) | C13—C14—C15—C17 | −1.0 (3) |
N1—C7—C8—C9 | 173.70 (18) | C13—C14—C15—C16 | 177.53 (18) |
C6—C7—C8—C9 | −6.5 (3) | C17—C15—C16—O5 | 6.6 (3) |
N1—C7—C8—C11 | −9.5 (3) | C14—C15—C16—O5 | −171.9 (2) |
C6—C7—C8—C11 | 170.29 (19) | C14—C15—C17—C18 | 0.7 (3) |
C7—C8—C9—O4 | −1.9 (3) | C16—C15—C17—C18 | −177.79 (19) |
C11—C8—C9—O4 | −178.8 (2) | C15—C17—C18—C12 | 0.7 (3) |
C7—C8—C9—O3 | 179.69 (18) | C13—C12—C18—C17 | −1.8 (3) |
C11—C8—C9—O3 | 2.8 (3) | C11—C12—C18—C17 | 176.73 (18) |
C7—C8—C11—C3 | 31.4 (2) | O1—C2—O2—C1 | −2.8 (3) |
C9—C8—C11—C3 | −151.73 (17) | C3—C2—O2—C1 | 176.83 (18) |
C7—C8—C11—C12 | −91.2 (2) | O4—C9—O3—C10 | −1.8 (3) |
C9—C8—C11—C12 | 85.7 (2) | C8—C9—O3—C10 | 176.73 (19) |
C4—C3—C11—C8 | −31.0 (2) | C8—C7—N1—C4 | −17.3 (3) |
C2—C3—C11—C8 | 150.61 (16) | C6—C7—N1—C4 | 162.9 (2) |
C4—C3—C11—C12 | 93.5 (2) | C3—C4—N1—C7 | 17.6 (3) |
C2—C3—C11—C12 | −84.9 (2) | C5—C4—N1—C7 | −160.32 (19) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O5i | 0.86 | 2.27 | 3.107 (2) | 163 |
Symmetry code: (i) −x+1, −y+2, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C18H19NO5 |
Mr | 329.34 |
Crystal system, space group | Triclinic, P1 |
Temperature (K) | 298 |
a, b, c (Å) | 8.219 (2), 10.432 (3), 10.979 (3) |
α, β, γ (°) | 111.364 (3), 102.799 (3), 101.150 (4) |
V (Å3) | 815.0 (4) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.48 × 0.34 × 0.10 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector |
Absorption correction | Multi-scan (SADABS: Sheldrick, 2004) |
Tmin, Tmax | 0.954, 0.990 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4173, 2855, 2352 |
Rint | 0.015 |
(sin θ/λ)max (Å−1) | 0.597 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.052, 0.140, 1.04 |
No. of reflections | 2855 |
No. of parameters | 221 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.25, −0.23 |
Computer programs: SMART (Bruker, 2001), SAINT (Bruker, 2001), SHELXS97 (Sheldrick, 1990), SHELXL97 (Sheldrick, 1997), SHELXTL (Sheldrick, 2001).
C3—C4 | 1.355 (3) | C7—C8 | 1.346 (3) |
C3—C11 | 1.522 (3) | C7—N1 | 1.381 (3) |
C4—N1 | 1.381 (3) | C8—C11 | 1.511 (2) |
C4—C3—C11 | 119.60 (17) | C8—C11—C3 | 110.09 (15) |
C3—C4—N1 | 118.15 (18) | C8—C11—C12 | 112.69 (15) |
C8—C7—N1 | 118.71 (17) | C3—C11—C12 | 109.55 (15) |
C7—C8—C11 | 119.69 (17) | C7—N1—C4 | 123.31 (16) |
O1—C2—C3—C4 | −18.6 (3) | C7—C8—C11—C3 | 31.4 (2) |
C11—C3—C4—N1 | 8.7 (3) | C4—C3—C11—C8 | −31.0 (2) |
N1—C7—C8—C11 | −9.5 (3) | C8—C11—C12—C18 | 27.1 (2) |
C7—C8—C9—O4 | −1.9 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1···O5i | 0.86 | 2.27 | 3.107 (2) | 163.0 |
Symmetry code: (i) −x+1, −y+2, −z+2. |
Acknowledgements
The authors are grateful to Dr Jianping Ma of Shandong Normal University for his help with the crystallographic analysis.
References
Bruker. (2001). SMART and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Fossheim, R., Svarteng, K. & Mostad, A. (1982). J. Med. Chem. 25, 126–131. CSD CrossRef CAS PubMed Web of Science Google Scholar
Hantzsch, A. & Liebigs, J. (1882). Ann. Chem. 215, 1–82. CrossRef Google Scholar
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Sheldrick, G. M. (1997). SHELXL97. University of Göttingen, Germany. Google Scholar
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It is well known that 1,4-dihydropyridines (DHPs) exhibit a wide range of biological activities, acting as potent vasodilators and antihypertensives (Janis & Triggle, 1983). The classical preparation method of 1,4-dihydropyridines is the Hantzsch reaction (Hantzsch & Liebigs, 1882). We have synthesized a series of 1,4-dihydropyridine compounds by the Hantzsch protocol in water. The structure of (I) was fully characterized by NMR (1H,13C), MS, IR, and elemental analysis and was confirmed by single-crystal X-ray crystallographic analysis (Figure 1).
The bond lengths and angles in (I) show normal values (Table 1) except for the geometry of the 1,4-dihydropyridine ring which adopts a flattened boat conformation with ring distortions at the nitrogen (Nl) and the tetrahedral carbon (C11). Both atoms are displaced to the same side of the ring with distances of 0.17Å and 0.39 Å, respectively, from the plane defined by C3, C4, C7, and C8, and thus form the apices of a boat-type conformation (Fossheim et al., 1982). The phenyl ring is almost perpendicular to the 1,4-dihydropyridine ring (N1—C4—C3—C11—C8—C7) with a dihedral angle of 92.40 (1)°. The bisect plane of the 1,4-dihydropyridine ring defined by N1, C11, and C12 makes a dihedral angle of 35.40 (7)° with the phenyl ring. The intermolecular hydrogen bonds N1—H1···O5i [symmetry code (i): -x + 1, -y + 2, -z + 2] between the pyridine N atom and a neighboring formyl O atom result in the formation of extended chains along the a axis (Figure 2).