organic compounds
E)-4-methoxy-2-{[(5-methylpyridin-2-yl)imino]methyl}phenol
of (aSchool of Chemical Sciences, 11800, USM Pulau Pinang, Malaysia
*Correspondence e-mail: farook@usm.my
The molecule of the title Schiff base compound, C14H14N2O2, displays an E conformation with respect the imine C=N double bond. The molecule is approximately planar, with the dihedral angle formed by the planes of the pyridine and benzene rings being 5.72 (6)°. There is an intramolecular hydrogen bond involving the phenolic H and imine N atoms.
CCDC reference: 1048553
1. Related literature
For the structure of related N-heterocyclic Schiff base compounds, see: Sahebalzamani et al. (2011); Rawat & Singh (2015); Thakar et al. (2015); Salam et al. (2011).
2. Experimental
2.1. Crystal data
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2.3. Refinement
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Data collection: APEX2 (Bruker, 2014); cell SAINT (Bruker, 2014); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Supporting information
CCDC reference: 1048553
https://doi.org/10.1107/S2056989015018113/rz5166sup1.cif
contains datablock I. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S2056989015018113/rz5166Isup2.hkl
Supporting information file. DOI: https://doi.org/10.1107/S2056989015018113/rz5166Isup3.cml
2-Hydroxy-5-methoxybenzaldehyde (5 mmol, 0.761 g) and 2-amino-5-methylpyridin (5 mmol, 0.541 g) were dissolved in ethanol in separate beakers, then the amine solution was added drop wise with stirring to the aldehyde in the round bottomed flask. Acetic acid was added and the solution was refluxed for 4 h under Ar atmosphere (Fig. 3). The solid product obtained was dried under reduced pressure overnight, then recrystallized with dichloromethane, diethyl ether and excess n-hexane, filtered, washed again with diethyl ether/n-hexane (1:3 v/v) and dried out over 24 h under reduced pressure in a desiccator. Purple single crystals of the title compound were grown on evaporation of an ethanol solution. M. p.: 380-381 K. Yield: 85%. Anal. calc. for C14H14N2O2 (FW: 242.28 g/mol): C, 69.43; H, 5.77; N, 11.55%. Found: C, 69.93; H, 5.69; N, 11.54%. IR (KBr pellets µmax/cm-1): 3427 ν(N—H), 2952 and 1384 ν(CH3), 1618 ν(C═N), 1497 ν(C═C, ar.), 1210 ν(C—O), 1035 ν(C—N).
The phenolic hydrogen atom was located in a difference Fourier map and refined freely. All other H atoms were calculated geometrically and refined using a riding model, with C—H = 0.93 Å, and with Uiso(H) = 1.2 Ueq(C) or 1.5 Ueq(C) for methyl H atoms. A rotating model was used for all methyl group. The H atoms of the methyl carbon attached to the pyridine ring are disordered over two sets of sites with an occupancy ratio of 0.61 (2):0.39 (2).
The molecule of the title compound (Fig. 1) has an E configuration about the imine C═N double bond, as indicated by the value of 179.11(12° of the C5-N2-C6-C7 torsion angle. The molecule is is almost planar, with a dihedral angle between the pyridine and benzene rings of 5.72 (6)°. The is stabilized by an intramolecular O—H···N hydrogen bond (Table 1) occurring between the phenolic hydrogen and imine nitrogen atoms. In the crystal, packing is stabilized only by van der Waals interactions.
For the structure of related N-heterocyclic Schiff base compounds, see: Sahebalzamani et al. (2011); Rawat & Singh (2015); Thakar et al. (2015); Salam et al. (2011).
Data collection: APEX2 (Bruker, 2014); cell
SAINT (Bruker, 2014); data reduction: SAINT (Bruker, 2014); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL2013 (Sheldrick, 2015); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C14H14N2O2 | F(000) = 512 |
Mr = 242.27 | Dx = 1.311 Mg m−3 |
Monoclinic, P21/n | Melting point: 380 K |
a = 12.7082 (12) Å | Mo Kα radiation, λ = 0.71073 Å |
b = 4.7446 (4) Å | θ = 1.7–27.6° |
c = 21.124 (2) Å | µ = 0.09 mm−1 |
β = 105.525 (2)° | T = 294 K |
V = 1227.21 (19) Å3 | Block, purple |
Z = 4 | 0.41 × 0.35 × 0.12 mm |
Bruker APEXII CCD diffractometer | 1910 reflections with I > 2σ(I) |
φ and ω scans | Rint = 0.028 |
Absorption correction: multi-scan (SABABS; Bruker, 2014) | θmax = 27.6°, θmin = 1.7° |
Tmin = 0.030, Tmax = 0.262 | h = −16→14 |
10950 measured reflections | k = −6→6 |
2848 independent reflections | l = −27→27 |
Refinement on F2 | 0 restraints |
Least-squares matrix: full | Hydrogen site location: mixed |
R[F2 > 2σ(F2)] = 0.044 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.151 | w = 1/[σ2(Fo2) + (0.0755P)2 + 0.121P] where P = (Fo2 + 2Fc2)/3 |
S = 1.07 | (Δ/σ)max < 0.001 |
2848 reflections | Δρmax = 0.17 e Å−3 |
170 parameters | Δρmin = −0.18 e Å−3 |
C14H14N2O2 | V = 1227.21 (19) Å3 |
Mr = 242.27 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 12.7082 (12) Å | µ = 0.09 mm−1 |
b = 4.7446 (4) Å | T = 294 K |
c = 21.124 (2) Å | 0.41 × 0.35 × 0.12 mm |
β = 105.525 (2)° |
Bruker APEXII CCD diffractometer | 2848 independent reflections |
Absorption correction: multi-scan (SABABS; Bruker, 2014) | 1910 reflections with I > 2σ(I) |
Tmin = 0.030, Tmax = 0.262 | Rint = 0.028 |
10950 measured reflections |
R[F2 > 2σ(F2)] = 0.044 | 0 restraints |
wR(F2) = 0.151 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.07 | Δρmax = 0.17 e Å−3 |
2848 reflections | Δρmin = −0.18 e Å−3 |
170 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. |
x | y | z | Uiso*/Ueq | Occ. (<1) | |
O1 | 0.11027 (10) | 0.5504 (3) | 0.07471 (7) | 0.0866 (5) | |
O2 | 0.52254 (10) | 0.4026 (3) | 0.24106 (6) | 0.0762 (4) | |
N1 | 0.57565 (9) | −0.2914 (3) | 0.07413 (6) | 0.0527 (3) | |
N2 | 0.55236 (9) | 0.0280 (3) | 0.15589 (6) | 0.0495 (3) | |
C1 | 0.63754 (12) | −0.4827 (3) | 0.05470 (8) | 0.0543 (4) | |
H1A | 0.6101 | −0.5632 | 0.0134 | 0.065* | |
C2 | 0.73934 (11) | −0.5698 (3) | 0.09138 (7) | 0.0476 (4) | |
C3 | 0.77704 (12) | −0.4503 (4) | 0.15259 (8) | 0.0558 (4) | |
H3A | 0.8446 | −0.5033 | 0.1797 | 0.067* | |
C4 | 0.71504 (12) | −0.2527 (4) | 0.17389 (7) | 0.0548 (4) | |
H4A | 0.7403 | −0.1707 | 0.2152 | 0.066* | |
C5 | 0.61512 (10) | −0.1780 (3) | 0.13323 (7) | 0.0445 (3) | |
C6 | 0.45685 (12) | 0.0882 (3) | 0.12034 (8) | 0.0521 (4) | |
H6A | 0.4309 | −0.0023 | 0.0801 | 0.063* | |
C7 | 0.38731 (11) | 0.2931 (3) | 0.14055 (7) | 0.0487 (4) | |
C8 | 0.42234 (12) | 0.4410 (3) | 0.19963 (7) | 0.0536 (4) | |
C9 | 0.35180 (14) | 0.6348 (4) | 0.21589 (8) | 0.0630 (5) | |
H9A | 0.3750 | 0.7380 | 0.2545 | 0.076* | |
C10 | 0.24841 (14) | 0.6764 (3) | 0.17591 (9) | 0.0621 (4) | |
H10A | 0.2021 | 0.8053 | 0.1880 | 0.074* | |
C11 | 0.21273 (13) | 0.5282 (4) | 0.11786 (9) | 0.0593 (4) | |
C12 | 0.28284 (12) | 0.3399 (4) | 0.10047 (8) | 0.0583 (4) | |
H12A | 0.2596 | 0.2422 | 0.0610 | 0.070* | |
C13 | 0.80422 (14) | −0.7829 (4) | 0.06515 (9) | 0.0651 (5) | |
H13A | 0.8653 | −0.8443 | 0.0999 | 0.098* | 0.61 (2) |
H13B | 0.8302 | −0.6989 | 0.0308 | 0.098* | 0.61 (2) |
H13C | 0.7587 | −0.9416 | 0.0479 | 0.098* | 0.61 (2) |
H13D | 0.8763 | −0.7110 | 0.0692 | 0.098* | 0.39 (2) |
H13E | 0.7689 | −0.8191 | 0.0197 | 0.098* | 0.39 (2) |
H13F | 0.8090 | −0.9547 | 0.0897 | 0.098* | 0.39 (2) |
C14 | 0.03899 (15) | 0.7589 (5) | 0.08715 (13) | 0.0898 (7) | |
H14A | −0.0274 | 0.7588 | 0.0523 | 0.135* | |
H14B | 0.0732 | 0.9404 | 0.0895 | 0.135* | |
H14C | 0.0227 | 0.7192 | 0.1281 | 0.135* | |
H1O2 | 0.5562 (19) | 0.261 (5) | 0.2213 (13) | 0.120 (9)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0597 (7) | 0.0913 (10) | 0.1072 (10) | 0.0322 (7) | 0.0198 (7) | −0.0079 (8) |
O2 | 0.0739 (8) | 0.0858 (10) | 0.0632 (7) | 0.0210 (7) | 0.0084 (6) | −0.0106 (7) |
N1 | 0.0450 (6) | 0.0544 (7) | 0.0554 (7) | 0.0084 (6) | 0.0076 (5) | −0.0070 (6) |
N2 | 0.0510 (7) | 0.0454 (7) | 0.0547 (7) | 0.0090 (5) | 0.0186 (5) | 0.0028 (6) |
C1 | 0.0491 (8) | 0.0565 (9) | 0.0558 (8) | 0.0042 (7) | 0.0113 (6) | −0.0122 (7) |
C2 | 0.0453 (7) | 0.0406 (7) | 0.0595 (8) | 0.0022 (6) | 0.0182 (6) | 0.0003 (7) |
C3 | 0.0449 (7) | 0.0614 (10) | 0.0567 (8) | 0.0126 (7) | 0.0057 (6) | 0.0021 (8) |
C4 | 0.0527 (8) | 0.0620 (10) | 0.0461 (7) | 0.0114 (7) | 0.0067 (6) | −0.0049 (7) |
C5 | 0.0448 (7) | 0.0409 (7) | 0.0494 (7) | 0.0047 (6) | 0.0151 (6) | 0.0012 (6) |
C6 | 0.0520 (8) | 0.0489 (8) | 0.0578 (8) | 0.0094 (7) | 0.0187 (7) | 0.0000 (7) |
C7 | 0.0524 (8) | 0.0419 (7) | 0.0576 (8) | 0.0073 (6) | 0.0247 (7) | 0.0058 (7) |
C8 | 0.0619 (9) | 0.0489 (8) | 0.0553 (8) | 0.0079 (7) | 0.0248 (7) | 0.0076 (7) |
C9 | 0.0803 (11) | 0.0557 (9) | 0.0618 (9) | 0.0118 (9) | 0.0342 (9) | −0.0001 (8) |
C10 | 0.0730 (10) | 0.0500 (9) | 0.0774 (11) | 0.0155 (8) | 0.0448 (9) | 0.0074 (8) |
C11 | 0.0554 (9) | 0.0545 (9) | 0.0749 (10) | 0.0134 (7) | 0.0293 (8) | 0.0078 (8) |
C12 | 0.0557 (8) | 0.0558 (9) | 0.0663 (9) | 0.0131 (8) | 0.0213 (7) | −0.0019 (8) |
C13 | 0.0633 (9) | 0.0536 (9) | 0.0842 (11) | 0.0102 (8) | 0.0297 (9) | −0.0057 (9) |
C14 | 0.0614 (10) | 0.0771 (13) | 0.1362 (19) | 0.0267 (10) | 0.0357 (11) | 0.0035 (13) |
O1—C11 | 1.379 (2) | C7—C12 | 1.388 (2) |
O1—C14 | 1.413 (2) | C7—C8 | 1.397 (2) |
O2—C8 | 1.3505 (19) | C8—C9 | 1.390 (2) |
O2—H1O2 | 0.95 (3) | C9—C10 | 1.373 (2) |
N1—C5 | 1.3282 (18) | C9—H9A | 0.9300 |
N1—C1 | 1.3356 (18) | C10—C11 | 1.381 (2) |
N2—C6 | 1.2771 (18) | C10—H10A | 0.9300 |
N2—C5 | 1.4231 (17) | C11—C12 | 1.379 (2) |
C1—C2 | 1.381 (2) | C12—H12A | 0.9300 |
C1—H1A | 0.9300 | C13—H13A | 0.9600 |
C2—C3 | 1.375 (2) | C13—H13B | 0.9600 |
C2—C13 | 1.501 (2) | C13—H13C | 0.9600 |
C3—C4 | 1.376 (2) | C13—H13D | 0.9600 |
C3—H3A | 0.9300 | C13—H13E | 0.9600 |
C4—C5 | 1.3754 (19) | C13—H13F | 0.9600 |
C4—H4A | 0.9300 | C14—H14A | 0.9600 |
C6—C7 | 1.4526 (19) | C14—H14B | 0.9600 |
C6—H6A | 0.9300 | C14—H14C | 0.9600 |
C11—O1—C14 | 118.00 (16) | C10—C9—H9A | 119.4 |
C8—O2—H1O2 | 105.5 (15) | C8—C9—H9A | 119.4 |
C5—N1—C1 | 117.31 (12) | C9—C10—C11 | 120.38 (14) |
C6—N2—C5 | 119.06 (13) | C9—C10—H10A | 119.8 |
N1—C1—C2 | 124.82 (14) | C11—C10—H10A | 119.8 |
N1—C1—H1A | 117.6 | C12—C11—O1 | 115.88 (16) |
C2—C1—H1A | 117.6 | C12—C11—C10 | 118.98 (16) |
C3—C2—C1 | 116.25 (13) | O1—C11—C10 | 125.14 (14) |
C3—C2—C13 | 122.49 (14) | C11—C12—C7 | 121.46 (16) |
C1—C2—C13 | 121.26 (14) | C11—C12—H12A | 119.3 |
C2—C3—C4 | 120.18 (13) | C7—C12—H12A | 119.3 |
C2—C3—H3A | 119.9 | C2—C13—H13A | 109.5 |
C4—C3—H3A | 119.9 | C2—C13—H13B | 109.5 |
C5—C4—C3 | 119.02 (14) | H13A—C13—H13B | 109.5 |
C5—C4—H4A | 120.5 | C2—C13—H13C | 109.5 |
C3—C4—H4A | 120.5 | H13A—C13—H13C | 109.5 |
N1—C5—C4 | 122.41 (13) | H13B—C13—H13C | 109.5 |
N1—C5—N2 | 119.32 (12) | C2—C13—H13D | 109.5 |
C4—C5—N2 | 118.27 (13) | C2—C13—H13E | 109.5 |
N2—C6—C7 | 122.28 (14) | H13D—C13—H13E | 109.5 |
N2—C6—H6A | 118.9 | C2—C13—H13F | 109.5 |
C7—C6—H6A | 118.9 | H13D—C13—H13F | 109.5 |
C12—C7—C8 | 119.25 (13) | H13E—C13—H13F | 109.5 |
C12—C7—C6 | 119.06 (14) | O1—C14—H14A | 109.5 |
C8—C7—C6 | 121.69 (14) | O1—C14—H14B | 109.5 |
O2—C8—C9 | 119.18 (15) | H14A—C14—H14B | 109.5 |
O2—C8—C7 | 122.08 (13) | O1—C14—H14C | 109.5 |
C9—C8—C7 | 118.74 (15) | H14A—C14—H14C | 109.5 |
C10—C9—C8 | 121.17 (16) | H14B—C14—H14C | 109.5 |
C5—N1—C1—C2 | −0.3 (2) | C12—C7—C8—O2 | 179.28 (14) |
N1—C1—C2—C3 | 1.0 (2) | C6—C7—C8—O2 | 0.2 (2) |
N1—C1—C2—C13 | −178.93 (14) | C12—C7—C8—C9 | −1.1 (2) |
C1—C2—C3—C4 | −0.9 (2) | C6—C7—C8—C9 | 179.78 (13) |
C13—C2—C3—C4 | 178.97 (14) | O2—C8—C9—C10 | −178.66 (14) |
C2—C3—C4—C5 | 0.3 (2) | C7—C8—C9—C10 | 1.7 (2) |
C1—N1—C5—C4 | −0.5 (2) | C8—C9—C10—C11 | −0.9 (2) |
C1—N1—C5—N2 | 179.64 (12) | C14—O1—C11—C12 | −174.24 (16) |
C3—C4—C5—N1 | 0.5 (2) | C14—O1—C11—C10 | 6.3 (3) |
C3—C4—C5—N2 | −179.64 (13) | C9—C10—C11—C12 | −0.6 (2) |
C6—N2—C5—N1 | 3.8 (2) | C9—C10—C11—O1 | 178.92 (15) |
C6—N2—C5—C4 | −176.11 (13) | O1—C11—C12—C7 | −178.37 (14) |
C5—N2—C6—C7 | 179.11 (12) | C10—C11—C12—C7 | 1.2 (3) |
N2—C6—C7—C12 | −177.58 (14) | C8—C7—C12—C11 | −0.3 (2) |
N2—C6—C7—C8 | 1.5 (2) | C6—C7—C12—C11 | 178.81 (14) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H1O2···N2 | 0.95 (2) | 1.76 (3) | 2.6276 (19) | 150 (2) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H1O2···N2 | 0.95 (2) | 1.76 (3) | 2.6276 (19) | 150 (2) |
Acknowledgements
The research was financially supported by the Third World Academy of Science (TWAS) and the RU grant 1001/PKIMIA/811269 from the Universiti Sains Malaysia.
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The molecule of the title compound (Fig. 1) has an E configuration about the imine C═N double bond, as indicated by the value of 179.11(12° of the C5-N2-C6-C7 torsion angle. The molecule is is almost planar, with a dihedral angle between the pyridine and benzene rings of 5.72 (6)°. The molecular conformation is stabilized by an intramolecular O—H···N hydrogen bond (Table 1) occurring between the phenolic hydrogen and imine nitrogen atoms. In the crystal, packing is stabilized only by van der Waals interactions.