organic compounds
Dimethyl 2,6-dimethyl-4-phenylpyridine-3,5-dicarboxylate
aDepartment of Chemistry, University of the Free State, PO Box 339, Bloemfontein 9300, South Africa
*Correspondence e-mail: muller.theunis@gmail.com
In the title compound, C17H17NO4, the dihedral angle between the benzene and pyridine rings is 75.51 (4)°. The benzene and pyridine rings are both approximately planar (r.m.s. deviations of 0.0040 and 0.0083 Å, respectively), indicating that the pyridine N atom is not protonated. The is stabilized by weak intermolecular C—H⋯O and C—H⋯N interactions.
Related literature
For the biological activity of pyridine derivatives, see: Lopez-Alarcon et al. (2004). For related structures, see: Rowan et al. (1996, 1997); Lou et al. (2010). For the sythesis, see: Debache et al. (2008). For the use of pyridine-type ligands in catalysis models, see: Roodt et al. (2011); van der Westhuizen et al. (2010) For standard bond lengths, see: Allen et al. (1987).
Experimental
Crystal data
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Refinement
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Data collection: APEX2 (Bruker, 2008); cell SAINT-Plus (Bruker, 2008); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).
Supporting information
https://doi.org/10.1107/S1600536811049865/fk2046sup1.cif
contains datablocks global, I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536811049865/fk2046Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S1600536811049865/fk2046Isup3.cml
1,4-dihydropyridine synthesis: Methylacetoacetate (2.5 mmol) and benzaldehyde (1 mmol) was added to ethanol (10 ml) and stirred. To this 5 mol % of phenyl boric acid was added as catalyst. The mixture was heated to reflux and stirred until completion. After completion of the reaction (monitored by TLC) the precipitated was filtered off and dried in oven at 60 °C before it was dissolved in a KOH (2 mmol) containing DMSO solution(3 ml). Molecular iodine 5 mol% was added and the mixture stirred at room temperature until completion of the reaction(TLC). Ice cold water (20 ml) was subsequently added and the reaction mixture stirred for 30 min, before the product was extracted into ethyl acetate (3 x 20 ml) and the solvent removed under reduced pressure to yield the title compound as a white powder. Crystals suitable for x-ray analysis where obtained by slow evaporation of hexane and dicloromethane mixture (9:1; 2 ml) at 4 °C.
1H NMR (600 MHz): 2.60 (s, 6H,2 x Methyl), 3.54 (s, 6H, 2 x methoxy), 7.24 (m, 2H, aromatic-H), 7.39 (m, 3H, aromatic-H).
13C NMR (150 MHz): 23.12, 52.35, 126.89, 126.87, 128.38, 128.68, 136.56, 146.41, 155.72, 168.59. m.p. 130–131 °C
H atoms were positioned geometrically and allowed to ride on their parent atoms, with Uiso(H) = 1.2Ueq(C) with a C—H distance of 0.95. The methyl H atoms were derived from difference maps (HFIX 137) and refined with Uiso(H) = 1.5Ueq(C) and C—H 0.98 Å.
1,4-Dihydropyridines (1,4-DHPs) belong to a class of nitrogen containing heterocycles having a six-membered ring. These are analogues of NADH coenzymes and are an important class of drugs (Lopez-Alarcon et al. 2004). The oxidation of 1,4-DHP`s into the corresponding pyridines is one of the main metabolic pathways of these drugs. The title compound can be prepared by the catalytic oxidation of 1,4-dihydropyridine. The dihydropyrimidine synthesized by the known procedure through three components process disclosed in the literature (Debache et al. 2008). The oxidation of the dihdropyridine was carried out in the presence of 5 mol% of I2 as a catalyst using DMSO as solvent. The title compound, C17H17N1O4, (Figure 1) crystallized in the monoclinic
P2(1)/c with Z = 4. The dihedral angle between the benzene ring and the pyridine ring is 75.51 (4)°. This compares well to 75.3 (4)° from the structure reported by Lou et al. (2010). The benzene ring (C8—C13) is flat (r.m.s = 0.0040) as well as the pyridine (N1, C1—C4) ring (r.m.s =0.0083). So the nitrogen in the pyridine ring is not protonated (Rowan et al., 1996 and 1997). The methyl groups at C1 and C5 are above the plane at 0.0165 (20) Å and 0.0589 (19)Å respectively. The carboxylate groups at C2 and C4 are also out of the plane by 0.0521 (18) and -0.1049 (18) Å respectively. Bond lengths and angles are within expected ranges (Allen et al., 1987). The packing is further stabilized by weak intermolecular C6—H6B···O3i, C7—H7B···O1ii, C15—H15A···O2iv and C13—H13···N1iii interactions (Table 1). (i = -x + 1, -y, -z + 1; ii = -x, -y, -z + 1; iii = x, -y - 1/2, z + 1/2; iv = -x, y + 1/2, -z + 1.5)For the biological activity of pyridine derivatives, see: Lopez-Alarcon et al. (2004). For related structures, see: Rowan et al. (1996, 1997); Lou et al. (2010). For the sythesis, see: Debache et al. (2008). For the use of pyridine-type ligands in catalysis models, see: Roodt et al. (2011); van der Westhuizen et al. (2010) For standard bond lengths, see: Allen et al. (1987).
Data collection: APEX2 (Bruker, 2008); cell
SAINT-Plus (Bruker, 2008); data reduction: SAINT-Plus (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: DIAMOND (Brandenburg & Putz, 2005); software used to prepare material for publication: WinGX (Farrugia, 1999).Fig. 1. Diamond representation of the title compound, showing the numbering scheme and displacement ellipsoids (50% probability). |
C17H17NO4 | F(000) = 632 |
Mr = 299.32 | Dx = 1.299 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
a = 16.0732 (4) Å | Cell parameters from 6764 reflections |
b = 7.2497 (2) Å | θ = 3.1–28.2° |
c = 13.1339 (3) Å | µ = 0.09 mm−1 |
β = 91.003 (1)° | T = 100 K |
V = 1530.20 (7) Å3 | Plate, colourless |
Z = 4 | 0.42 × 0.36 × 0.18 mm |
Bruker APEXII CCD diffractometer | 3132 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.036 |
φ and ω scans | θmax = 28.3°, θmin = 1.3° |
Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | h = −19→21 |
Tmin = 0.962, Tmax = 0.984 | k = −9→9 |
26541 measured reflections | l = −17→16 |
3782 independent reflections |
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)] = 0.042 | Hydrogen site location: geom and difmap |
wR(F2) = 0.114 | H-atom parameters constrained |
S = 1.05 | w = 1/[σ2(Fo2) + (0.0581P)2 + 0.5155P] where P = (Fo2 + 2Fc2)/3 |
3782 reflections | (Δ/σ)max = 0.001 |
203 parameters | Δρmax = 0.31 e Å−3 |
0 restraints | Δρmin = −0.25 e Å−3 |
C17H17NO4 | V = 1530.20 (7) Å3 |
Mr = 299.32 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 16.0732 (4) Å | µ = 0.09 mm−1 |
b = 7.2497 (2) Å | T = 100 K |
c = 13.1339 (3) Å | 0.42 × 0.36 × 0.18 mm |
β = 91.003 (1)° |
Bruker APEXII CCD diffractometer | 3782 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 2004) | 3132 reflections with I > 2σ(I) |
Tmin = 0.962, Tmax = 0.984 | Rint = 0.036 |
26541 measured reflections |
R[F2 > 2σ(F2)] = 0.042 | 0 restraints |
wR(F2) = 0.114 | H-atom parameters constrained |
S = 1.05 | Δρmax = 0.31 e Å−3 |
3782 reflections | Δρmin = −0.25 e Å−3 |
203 parameters |
Experimental. The intensity data was collected on a Bruker X8 ApexII 4 K Kappa CCD diffractometer using an exposure time of 10 s/frame. A total of 1659 frames were collected with a frame width of 0.5° covering up to θ = 28.26° with 99.9% completeness accomplished. |
Geometry. All s.u.'s (except the s.u. in the dihedral angle between two l.s. planes) are estimated using the full covariance matrix. The cell s.u.'s are taken into account individually in the estimation of s.u.'s in distances, angles and torsion angles; correlations between s.u.'s in cell parameters are only used when they are defined by crystal symmetry. An approximate (isotropic) treatment of cell s.u.'s is used for estimating s.u.'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 > 2σ(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 | 0.31920 (7) | −0.26904 (16) | 0.51421 (9) | 0.0155 (2) | |
C2 | 0.32461 (7) | −0.11146 (15) | 0.57614 (9) | 0.0143 (2) | |
C3 | 0.25177 (7) | −0.02892 (15) | 0.61091 (8) | 0.0135 (2) | |
C4 | 0.17589 (7) | −0.11187 (15) | 0.58352 (9) | 0.0143 (2) | |
C5 | 0.17515 (7) | −0.27106 (16) | 0.52304 (9) | 0.0151 (2) | |
C6 | 0.39463 (8) | −0.36532 (18) | 0.47394 (11) | 0.0233 (3) | |
H6A | 0.4141 | −0.4576 | 0.5234 | 0.035* | |
H6B | 0.4388 | −0.2748 | 0.4627 | 0.035* | |
H6C | 0.3802 | −0.4263 | 0.4094 | 0.035* | |
C7 | 0.09654 (8) | −0.37102 (17) | 0.49311 (10) | 0.0209 (3) | |
H7A | 0.1002 | −0.413 | 0.4224 | 0.031* | |
H7B | 0.049 | −0.2875 | 0.4995 | 0.031* | |
H7C | 0.0892 | −0.4777 | 0.5379 | 0.031* | |
C8 | 0.25268 (7) | 0.13135 (15) | 0.68224 (9) | 0.0140 (2) | |
C9 | 0.27156 (7) | 0.30990 (16) | 0.65095 (9) | 0.0176 (2) | |
H9 | 0.2869 | 0.3325 | 0.5826 | 0.021* | |
C10 | 0.26785 (8) | 0.45503 (16) | 0.71995 (9) | 0.0196 (3) | |
H10 | 0.28 | 0.5769 | 0.6982 | 0.023* | |
C11 | 0.24653 (7) | 0.42316 (17) | 0.82023 (9) | 0.0188 (3) | |
H11 | 0.2441 | 0.5229 | 0.867 | 0.023* | |
C12 | 0.22882 (8) | 0.24556 (18) | 0.85221 (9) | 0.0213 (3) | |
H12 | 0.2148 | 0.2232 | 0.9211 | 0.026* | |
C13 | 0.23166 (8) | 0.10024 (17) | 0.78347 (9) | 0.0188 (3) | |
H13 | 0.2192 | −0.0213 | 0.8055 | 0.023* | |
C14 | 0.09598 (7) | −0.02242 (16) | 0.61348 (9) | 0.0168 (2) | |
C15 | −0.02859 (8) | −0.0577 (2) | 0.70350 (13) | 0.0324 (3) | |
H15A | −0.0238 | 0.0649 | 0.7345 | 0.049* | |
H15B | −0.0548 | −0.1425 | 0.7514 | 0.049* | |
H15C | −0.0627 | −0.0498 | 0.6411 | 0.049* | |
C16 | 0.40794 (7) | −0.03409 (16) | 0.60534 (9) | 0.0163 (2) | |
C17 | 0.53414 (8) | −0.0953 (2) | 0.69408 (12) | 0.0314 (3) | |
H17A | 0.568 | −0.0971 | 0.6327 | 0.047* | |
H17B | 0.5573 | −0.1822 | 0.7442 | 0.047* | |
H17C | 0.5344 | 0.0293 | 0.723 | 0.047* | |
N1 | 0.24576 (6) | −0.34462 (13) | 0.48819 (7) | 0.0154 (2) | |
O1 | 0.07254 (6) | 0.12423 (12) | 0.58103 (8) | 0.0250 (2) | |
O2 | 0.05370 (6) | −0.12553 (12) | 0.67903 (7) | 0.0227 (2) | |
O3 | 0.43443 (6) | 0.11142 (12) | 0.57660 (8) | 0.0236 (2) | |
O4 | 0.44906 (6) | −0.14856 (13) | 0.66776 (7) | 0.0255 (2) |
U11 | U22 | U33 | U12 | U13 | U23 | |
C1 | 0.0148 (5) | 0.0143 (5) | 0.0174 (5) | −0.0007 (4) | 0.0027 (4) | 0.0020 (4) |
C2 | 0.0138 (5) | 0.0132 (5) | 0.0159 (5) | −0.0015 (4) | 0.0001 (4) | 0.0024 (4) |
C3 | 0.0154 (5) | 0.0111 (5) | 0.0139 (5) | −0.0003 (4) | 0.0003 (4) | 0.0026 (4) |
C4 | 0.0141 (5) | 0.0131 (5) | 0.0158 (5) | 0.0002 (4) | 0.0002 (4) | 0.0020 (4) |
C5 | 0.0150 (5) | 0.0136 (5) | 0.0166 (5) | −0.0012 (4) | −0.0008 (4) | 0.0017 (4) |
C6 | 0.0168 (6) | 0.0202 (6) | 0.0331 (7) | −0.0010 (5) | 0.0066 (5) | −0.0062 (5) |
C7 | 0.0157 (6) | 0.0183 (6) | 0.0286 (7) | −0.0023 (5) | −0.0019 (5) | −0.0055 (5) |
C8 | 0.0126 (5) | 0.0137 (5) | 0.0157 (5) | −0.0002 (4) | −0.0015 (4) | −0.0002 (4) |
C9 | 0.0213 (6) | 0.0154 (6) | 0.0162 (5) | −0.0018 (4) | 0.0009 (4) | 0.0014 (4) |
C10 | 0.0232 (6) | 0.0131 (5) | 0.0223 (6) | −0.0020 (5) | −0.0023 (5) | 0.0001 (5) |
C11 | 0.0183 (6) | 0.0181 (6) | 0.0197 (6) | 0.0012 (4) | −0.0024 (5) | −0.0056 (4) |
C12 | 0.0261 (6) | 0.0228 (6) | 0.0151 (5) | −0.0013 (5) | 0.0012 (5) | −0.0001 (5) |
C13 | 0.0232 (6) | 0.0153 (5) | 0.0179 (6) | −0.0022 (5) | 0.0001 (5) | 0.0024 (4) |
C14 | 0.0142 (5) | 0.0155 (5) | 0.0207 (6) | −0.0016 (4) | −0.0015 (4) | −0.0030 (4) |
C15 | 0.0200 (7) | 0.0269 (7) | 0.0508 (9) | 0.0028 (5) | 0.0155 (6) | 0.0014 (6) |
C16 | 0.0135 (5) | 0.0167 (6) | 0.0189 (6) | 0.0001 (4) | 0.0020 (4) | −0.0020 (4) |
C17 | 0.0180 (6) | 0.0337 (8) | 0.0422 (8) | −0.0033 (5) | −0.0109 (6) | 0.0044 (6) |
N1 | 0.0169 (5) | 0.0133 (5) | 0.0160 (5) | −0.0006 (4) | 0.0007 (4) | 0.0009 (4) |
O1 | 0.0198 (5) | 0.0183 (4) | 0.0368 (5) | 0.0049 (3) | 0.0015 (4) | 0.0042 (4) |
O2 | 0.0173 (4) | 0.0203 (4) | 0.0308 (5) | 0.0013 (3) | 0.0084 (4) | 0.0020 (4) |
O3 | 0.0174 (4) | 0.0173 (4) | 0.0361 (5) | −0.0043 (3) | 0.0001 (4) | 0.0031 (4) |
O4 | 0.0178 (4) | 0.0254 (5) | 0.0330 (5) | −0.0043 (4) | −0.0084 (4) | 0.0081 (4) |
C1—N1 | 1.3402 (15) | C9—H9 | 0.95 |
C1—C2 | 1.4042 (16) | C10—C11 | 1.3861 (17) |
C1—C6 | 1.5032 (16) | C10—H10 | 0.95 |
C2—C3 | 1.3986 (15) | C11—C12 | 1.3854 (18) |
C2—C16 | 1.4958 (16) | C11—H11 | 0.95 |
C3—C4 | 1.4011 (15) | C12—C13 | 1.3887 (17) |
C3—C8 | 1.4924 (15) | C12—H12 | 0.95 |
C4—C5 | 1.4009 (16) | C13—H13 | 0.95 |
C4—C14 | 1.4977 (16) | C14—O1 | 1.2034 (15) |
C5—N1 | 1.3417 (15) | C14—O2 | 1.3350 (15) |
C5—C7 | 1.5030 (16) | C15—O2 | 1.4524 (15) |
C6—H6A | 0.98 | C15—H15A | 0.98 |
C6—H6B | 0.98 | C15—H15B | 0.98 |
C6—H6C | 0.98 | C15—H15C | 0.98 |
C7—H7A | 0.98 | C16—O3 | 1.2009 (15) |
C7—H7B | 0.98 | C16—O4 | 1.3338 (15) |
C7—H7C | 0.98 | C17—O4 | 1.4568 (15) |
C8—C9 | 1.3932 (16) | C17—H17A | 0.98 |
C8—C13 | 1.3959 (16) | C17—H17B | 0.98 |
C9—C10 | 1.3906 (17) | C17—H17C | 0.98 |
N1—C1—C2 | 121.72 (10) | C11—C10—C9 | 120.48 (11) |
N1—C1—C6 | 115.63 (10) | C11—C10—H10 | 119.8 |
C2—C1—C6 | 122.64 (11) | C9—C10—H10 | 119.8 |
C3—C2—C1 | 119.57 (10) | C12—C11—C10 | 119.90 (11) |
C3—C2—C16 | 120.45 (10) | C12—C11—H11 | 120 |
C1—C2—C16 | 119.98 (10) | C10—C11—H11 | 120 |
C2—C3—C4 | 117.54 (10) | C11—C12—C13 | 119.92 (11) |
C2—C3—C8 | 122.61 (10) | C11—C12—H12 | 120 |
C4—C3—C8 | 119.62 (10) | C13—C12—H12 | 120 |
C5—C4—C3 | 119.86 (10) | C12—C13—C8 | 120.52 (11) |
C5—C4—C14 | 120.45 (10) | C12—C13—H13 | 119.7 |
C3—C4—C14 | 119.57 (10) | C8—C13—H13 | 119.7 |
N1—C5—C4 | 121.47 (10) | O1—C14—O2 | 124.29 (11) |
N1—C5—C7 | 115.56 (10) | O1—C14—C4 | 123.65 (11) |
C4—C5—C7 | 122.97 (10) | O2—C14—C4 | 112.06 (10) |
C1—C6—H6A | 109.5 | O2—C15—H15A | 109.5 |
C1—C6—H6B | 109.5 | O2—C15—H15B | 109.5 |
H6A—C6—H6B | 109.5 | H15A—C15—H15B | 109.5 |
C1—C6—H6C | 109.5 | O2—C15—H15C | 109.5 |
H6A—C6—H6C | 109.5 | H15A—C15—H15C | 109.5 |
H6B—C6—H6C | 109.5 | H15B—C15—H15C | 109.5 |
C5—C7—H7A | 109.5 | O3—C16—O4 | 124.40 (11) |
C5—C7—H7B | 109.5 | O3—C16—C2 | 124.73 (11) |
H7A—C7—H7B | 109.5 | O4—C16—C2 | 110.87 (10) |
C5—C7—H7C | 109.5 | O4—C17—H17A | 109.5 |
H7A—C7—H7C | 109.5 | O4—C17—H17B | 109.5 |
H7B—C7—H7C | 109.5 | H17A—C17—H17B | 109.5 |
C9—C8—C13 | 119.26 (11) | O4—C17—H17C | 109.5 |
C9—C8—C3 | 122.55 (10) | H17A—C17—H17C | 109.5 |
C13—C8—C3 | 118.18 (10) | H17B—C17—H17C | 109.5 |
C10—C9—C8 | 119.91 (11) | C1—N1—C5 | 119.80 (10) |
C10—C9—H9 | 120 | C14—O2—C15 | 115.40 (10) |
C8—C9—H9 | 120 | C16—O4—C17 | 115.72 (10) |
D—H···A | D—H | H···A | D···A | D—H···A |
C6—H6B···O3i | 0.98 | 2.42 | 3.3825 (15) | 167 |
C7—H7B···O1ii | 0.98 | 2.5 | 3.3826 (15) | 149 |
C13—H13···N1iii | 0.95 | 2.62 | 3.2701 (16) | 126 |
C15—H15A···O2iv | 0.98 | 2.56 | 3.5187 (17) | 165 |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x, −y, −z+1; (iii) x, −y−1/2, z+1/2; (iv) −x, y+1/2, −z+3/2. |
Experimental details
Crystal data | |
Chemical formula | C17H17NO4 |
Mr | 299.32 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 100 |
a, b, c (Å) | 16.0732 (4), 7.2497 (2), 13.1339 (3) |
β (°) | 91.003 (1) |
V (Å3) | 1530.20 (7) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.42 × 0.36 × 0.18 |
Data collection | |
Diffractometer | Bruker APEXII CCD |
Absorption correction | Multi-scan (SADABS; Sheldrick, 2004) |
Tmin, Tmax | 0.962, 0.984 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 26541, 3782, 3132 |
Rint | 0.036 |
(sin θ/λ)max (Å−1) | 0.666 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.042, 0.114, 1.05 |
No. of reflections | 3782 |
No. of parameters | 203 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.31, −0.25 |
Computer programs: APEX2 (Bruker, 2008), SAINT-Plus (Bruker, 2008), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), DIAMOND (Brandenburg & Putz, 2005), WinGX (Farrugia, 1999).
D—H···A | D—H | H···A | D···A | D—H···A |
C6—H6B···O3i | 0.98 | 2.42 | 3.3825 (15) | 167.1 |
C7—H7B···O1ii | 0.98 | 2.5 | 3.3826 (15) | 149.3 |
C13—H13···N1iii | 0.95 | 2.62 | 3.2701 (16) | 126.3 |
C15—H15A···O2iv | 0.98 | 2.56 | 3.5187 (17) | 164.5 |
Symmetry codes: (i) −x+1, −y, −z+1; (ii) −x, −y, −z+1; (iii) x, −y−1/2, z+1/2; (iv) −x, y+1/2, −z+3/2. |
Acknowledgements
The University of the Free State and Sasol Ltd are gratefully acknowledged for financial support and Johannes van Tonder for the NMR data and help with the synthesis of the title compound. Special thanks are due to Prof Andreas Roodt.
References
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1,4-Dihydropyridines (1,4-DHPs) belong to a class of nitrogen containing heterocycles having a six-membered ring. These are analogues of NADH coenzymes and are an important class of drugs (Lopez-Alarcon et al. 2004). The oxidation of 1,4-DHP`s into the corresponding pyridines is one of the main metabolic pathways of these drugs. The title compound can be prepared by the catalytic oxidation of 1,4-dihydropyridine. The dihydropyrimidine synthesized by the known procedure through three components process disclosed in the literature (Debache et al. 2008). The oxidation of the dihdropyridine was carried out in the presence of 5 mol% of I2 as a catalyst using DMSO as solvent. The title compound, C17H17N1O4, (Figure 1) crystallized in the monoclinic space group P2(1)/c with Z = 4. The dihedral angle between the benzene ring and the pyridine ring is 75.51 (4)°. This compares well to 75.3 (4)° from the structure reported by Lou et al. (2010). The benzene ring (C8—C13) is flat (r.m.s = 0.0040) as well as the pyridine (N1, C1—C4) ring (r.m.s =0.0083). So the nitrogen in the pyridine ring is not protonated (Rowan et al., 1996 and 1997). The methyl groups at C1 and C5 are above the plane at 0.0165 (20) Å and 0.0589 (19)Å respectively. The carboxylate groups at C2 and C4 are also out of the plane by 0.0521 (18) and -0.1049 (18) Å respectively. Bond lengths and angles are within expected ranges (Allen et al., 1987). The packing is further stabilized by weak intermolecular C6—H6B···O3i, C7—H7B···O1ii, C15—H15A···O2iv and C13—H13···N1iii interactions (Table 1). (i = -x + 1, -y, -z + 1; ii = -x, -y, -z + 1; iii = x, -y - 1/2, z + 1/2; iv = -x, y + 1/2, -z + 1.5)