supplementary materials


hb7078 scheme

Acta Cryst. (2013). E69, o871    [ doi:10.1107/S1600536813012233 ]

6-[(2,4-Dimethylanilino)methylidene]-2-hydroxycyclohexa-2,4-dienone

S. Shujah, S. Ali, Zia-ur-Rehman, M. N. Tahir and A. Meetsma

Abstract top

In the title compound, C15H15NO2, the dihedral angle between the aromatic rings is 5.86 (6)°, and an intramolecular N-H...O hydrogen bond generates an S(6) motif, which helps to stabilize the enamine-keto tautomer. An intramolecular O-H...O hydrogen bond also occurs. In the crystal, inversion dimers linked by pairs of O-H...O hydrogen bonds generate R22(10) loops. A C-H...O interaction links the dimers into [010] chains and aromatic [pi]-[pi] stacking [centroid-centroid separation = 3.6131 (9) Å] also occurs.

Comment top

As part of our ongoing studies of Schiff bases (Shuja et al. 2007), here we report the synthesis and structure of title compound, (I), (Fig. 1). In the molecular structure of (I) the bond distances C7–O2 [1.298 (13) Å] and C1–N1 [1.311 (14) Å] indicate keto-amino tautomeric form. This is further confirmed by a formation of strong intramolecular hydrogen bond N–H···O [N···O = 2.587 (12) Å] resulting in an S(6) ring. The C8–N1–C1–C2 torsion angle is 179.91 (12). The C1–N1 bond length [1.311 (14) Å] is smaller than the N1–C8 bond length [1.417 (14) Å]. The C1–C2 bond length [1.416 (16) Å] indicate a double-bond character and the short C5–C6 bond distance [1.372 (16) Å] of benzene core suggests the presence of quinoid effect (Blagus et al., 2011). The molecules are connected by ππ interactions and O–H···O hydrogen bonds forming a two dimensional network (Fig. 2)

Related literature top

For a related structure and background to Schiff bases, see: Shuja et al. (2007). For further structural aspects, see: Blagus & Kaitner (2011).

Experimental top

An ethanolic solution (50 ml) of 2,4-dimethylaniline (2.5 mmol, 0.30 g) was added dropwise with constant stirring to a hot ethanolic solution (50 ml) of 2,3-dihydroxybenzaldehyde (2.5 mmol, 0.34 g) in a round bottomed flask equipped with a water condenser. The reaction mixture was kept under reflux for 2 h, cooled and kept at room temperature for 48 h. Red blocks of (I) were obtained on slow evaporation of the solvent.

Computing details top

Data collection: SMART (Bruker, 2006); cell refinement: SAINT-Plus (Bruker, 2006); data reduction: SAINT-Plus (Bruker, 2006); program(s) used to solve structure: SIR2004 (Burla et al., 2005); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: PLUTO (Meetsma, 2006) and PLATON (Spek, 2009); software used to prepare material for publication: PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular stucture of (I), with displacement ellipsoids drawn at the 50% probability level. The intramolecular N—H···O hydrogen bond is shown as dashed lines.
[Figure 2] Fig. 2. Schiff base molecules connected by ππ interactions and O—H···O hydrogen bonds.
6-[(2,4-Dimethylanilino)methylidene]-2-hydroxycyclohexa-2,4-dienone top
Crystal data top
C15H15NO2Z = 2
Mr = 241.28F(000) = 256
Triclinic, P1The final unit cell was obtained from the xyz centroids of 3645 reflections after integration using the SAINTPLUS software package (Bruker, 2000).
Hall symbol: -P 1Dx = 1.353 Mg m3
a = 7.6731 (8) ÅMo Kα radiation, λ = 0.71073 Å
b = 8.4348 (9) ÅCell parameters from 3645 reflections
c = 10.5806 (12) Åθ = 2.7–29.6°
α = 80.6107 (18)°µ = 0.09 mm1
β = 75.8216 (19)°T = 100 K
γ = 63.3573 (16)°Block, red
V = 592.31 (11) Å30.53 × 0.48 × 0.29 mm
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer
2363 independent reflections
Radiation source: fine focus sealed Siemens Mo tube2148 reflections with I > 2σ(I)
Parallel mounted graphite monochromatorRint = 0.009
Detector resolution: 4096x4096 / 62x62 (binned 512) pixels mm-1θmax = 26.4°, θmin = 2.7°
φ and ω scansh = 99
Absorption correction: multi-scan
(SADABS; Bruker, 2006)
k = 1010
Tmin = 0.943, Tmax = 0.974l = 1313
4681 measured reflections
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: structure-invariant direct methods
R[F2 > 2σ(F2)] = 0.043Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.123All H-atom parameters refined
S = 1.09 w = 1/[σ2(Fo2) + (0.0825P)2 + 0.0862P]
where P = (Fo2 + 2Fc2)/3
2363 reflections(Δ/σ)max < 0.001
223 parametersΔρmax = 0.29 e Å3
0 restraintsΔρmin = 0.27 e Å3
Crystal data top
C15H15NO2γ = 63.3573 (16)°
Mr = 241.28V = 592.31 (11) Å3
Triclinic, P1Z = 2
a = 7.6731 (8) ÅMo Kα radiation
b = 8.4348 (9) ŵ = 0.09 mm1
c = 10.5806 (12) ÅT = 100 K
α = 80.6107 (18)°0.53 × 0.48 × 0.29 mm
β = 75.8216 (19)°
Data collection top
Bruker SMART APEX CCD area-detector
diffractometer
2363 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2006)
2148 reflections with I > 2σ(I)
Tmin = 0.943, Tmax = 0.974Rint = 0.009
4681 measured reflectionsθmax = 26.4°
Refinement top
R[F2 > 2σ(F2)] = 0.043All H-atom parameters refined
wR(F2) = 0.123Δρmax = 0.29 e Å3
S = 1.09Δρmin = 0.27 e Å3
2363 reflectionsAbsolute structure: ?
223 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
Special details top

Geometry. Bond distances, angles etc. have been calculated using the rounded fractional coordinates. All su's are estimated from the variances of the (full) variance-covariance matrix. The cell e.s.d.'s are taken into account in the estimation of distances, angles and torsion angles

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.14548 (13)0.99696 (10)0.64979 (8)0.0261 (3)
O20.14914 (11)0.77675 (9)0.48083 (7)0.0213 (2)
N10.23552 (13)0.45820 (12)0.42735 (8)0.0179 (3)
C10.29515 (15)0.40370 (14)0.53911 (10)0.0198 (3)
C20.28631 (15)0.52113 (14)0.62454 (10)0.0180 (3)
C30.35444 (16)0.45246 (14)0.74426 (10)0.0214 (3)
C40.35457 (16)0.56226 (14)0.82597 (10)0.0217 (3)
C50.28454 (16)0.74722 (14)0.79198 (10)0.0209 (3)
C60.21286 (16)0.81822 (14)0.67902 (10)0.0195 (3)
C70.21212 (15)0.70814 (14)0.58908 (10)0.0178 (3)
C80.23908 (15)0.35066 (13)0.33599 (10)0.0173 (3)
C90.18384 (15)0.43224 (13)0.21664 (10)0.0182 (3)
C100.18940 (16)0.32622 (14)0.12556 (10)0.0194 (3)
C110.24356 (16)0.14426 (14)0.15117 (10)0.0203 (3)
C120.29389 (16)0.06799 (14)0.27204 (11)0.0215 (3)
C130.29397 (16)0.16855 (14)0.36332 (10)0.0201 (3)
C140.11771 (17)0.62921 (14)0.18686 (10)0.0220 (3)
C150.24119 (18)0.03446 (15)0.05288 (12)0.0250 (3)
H10.351 (2)0.273 (2)0.5651 (14)0.034 (4)*
H30.400 (2)0.323 (2)0.7672 (15)0.042 (4)*
H40.401 (2)0.5179 (18)0.9075 (14)0.027 (3)*
H50.286 (2)0.8279 (19)0.8468 (14)0.031 (4)*
H100.1540 (19)0.3814 (17)0.0398 (13)0.024 (3)*
H120.326 (2)0.062 (2)0.2955 (14)0.036 (4)*
H130.328 (2)0.1118 (18)0.4479 (13)0.026 (3)*
H140.218 (2)0.6672 (19)0.1967 (14)0.037 (4)*
H14'0.096 (2)0.6606 (19)0.0969 (14)0.033 (4)*
H14"0.010 (2)0.6970 (19)0.2456 (14)0.033 (4)*
H150.251 (3)0.088 (2)0.0373 (18)0.049 (5)*
H15'0.353 (2)0.084 (2)0.0470 (16)0.047 (4)*
H15"0.122 (3)0.016 (2)0.0749 (16)0.046 (4)*
H210.076 (3)1.025 (2)0.5909 (19)0.052 (5)*
H310.187 (3)0.590 (3)0.412 (2)0.088 (7)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0360 (5)0.0169 (4)0.0268 (4)0.0088 (3)0.0143 (4)0.0005 (3)
O20.0259 (4)0.0177 (4)0.0188 (4)0.0070 (3)0.0078 (3)0.0007 (3)
N10.0187 (5)0.0161 (4)0.0183 (4)0.0068 (3)0.0035 (3)0.0018 (3)
C10.0189 (5)0.0172 (5)0.0211 (5)0.0060 (4)0.0037 (4)0.0011 (4)
C20.0169 (5)0.0176 (5)0.0178 (5)0.0058 (4)0.0031 (4)0.0015 (4)
C30.0210 (5)0.0194 (5)0.0207 (5)0.0057 (4)0.0053 (4)0.0002 (4)
C40.0188 (5)0.0251 (5)0.0185 (5)0.0061 (4)0.0057 (4)0.0009 (4)
C50.0201 (5)0.0239 (5)0.0191 (5)0.0086 (4)0.0034 (4)0.0051 (4)
C60.0190 (5)0.0173 (5)0.0211 (5)0.0069 (4)0.0028 (4)0.0028 (4)
C70.0157 (5)0.0193 (5)0.0169 (5)0.0066 (4)0.0026 (4)0.0009 (4)
C80.0156 (5)0.0175 (5)0.0188 (5)0.0070 (4)0.0025 (4)0.0029 (4)
C90.0167 (5)0.0170 (5)0.0200 (5)0.0067 (4)0.0030 (4)0.0014 (4)
C100.0192 (5)0.0206 (5)0.0187 (5)0.0083 (4)0.0043 (4)0.0014 (4)
C110.0180 (5)0.0200 (5)0.0233 (5)0.0081 (4)0.0021 (4)0.0055 (4)
C120.0206 (5)0.0169 (5)0.0259 (5)0.0073 (4)0.0045 (4)0.0010 (4)
C130.0204 (5)0.0177 (5)0.0215 (5)0.0074 (4)0.0053 (4)0.0001 (4)
C140.0283 (6)0.0172 (5)0.0204 (5)0.0084 (4)0.0083 (4)0.0002 (4)
C150.0275 (6)0.0221 (5)0.0272 (6)0.0102 (5)0.0064 (4)0.0061 (4)
Geometric parameters (Å, º) top
O1—C61.3649 (13)C10—C111.3961 (15)
O2—C71.2978 (13)C11—C121.3961 (16)
O1—H210.85 (2)C11—C151.5094 (17)
N1—C11.3107 (14)C12—C131.3857 (16)
N1—C81.4174 (14)C1—H11.005 (15)
N1—H311.00 (2)C3—H30.993 (15)
C1—C21.4158 (16)C4—H40.968 (15)
C2—C31.4237 (15)C5—H50.969 (15)
C2—C71.4350 (15)C10—H100.992 (14)
C3—C41.3666 (16)C12—H121.012 (15)
C4—C51.4184 (15)C13—H130.980 (14)
C5—C61.3721 (16)C14—H140.988 (17)
C6—C71.4365 (16)C14—H14'0.980 (15)
C8—C91.4018 (15)C14—H14"0.994 (15)
C8—C131.3982 (15)C15—H150.987 (18)
C9—C141.5061 (15)C15—H15'0.982 (16)
C9—C101.3989 (15)C15—H15"0.96 (2)
O1···O22.7674 (12)C4···H14iv2.938 (16)
O1···C13i3.3069 (14)C4···H14'vi3.059 (15)
O1···O2ii2.7320 (13)C5···H15"iii2.98 (2)
O1···C14ii3.3713 (14)C7···H312.35 (2)
O2···O1ii2.7320 (13)C12···H3vii3.096 (15)
O2···C12i3.4092 (14)C13···H21v2.99 (2)
O2···O12.7674 (12)C13···H12.635 (15)
O2···N12.5873 (12)C14···H312.50 (2)
O2···C13iii3.2538 (16)C15···H5viii2.871 (15)
O1···H13i2.557 (14)H1···C132.635 (15)
O1···H14"ii2.633 (14)H1···H32.39 (2)
O2···H311.72 (2)H1···H132.07 (2)
O2···H12i2.649 (16)H3···H12.39 (2)
O2···H212.340 (17)H3···C12vii3.096 (15)
O2···H21ii1.999 (19)H3···H12vii2.31 (2)
N1···O22.5873 (12)H5···C15ix2.871 (15)
N1···H142.762 (14)H5···H15ix2.57 (2)
N1···H14"2.900 (15)H5···H15'ix2.59 (2)
C1···C2iv3.5296 (18)H10···C4x3.015 (14)
C1···C7iv3.4250 (18)H10···H14'2.35 (2)
C2···C9iii3.4592 (18)H10···H152.46 (2)
C2···C1iv3.5296 (18)H10···H10xi2.55 (2)
C2···C2iv3.5848 (17)H12···O2v2.649 (16)
C4···C9iv3.4797 (19)H12···H3vii2.31 (2)
C4···C8iv3.4962 (18)H13···O1v2.557 (14)
C5···C13iv3.5694 (19)H13···C12.675 (14)
C5···C8iv3.3332 (18)H13···H12.07 (2)
C6···C12iii3.4839 (19)H13···H21v2.46 (3)
C6···C11iii3.4209 (19)H14···N12.762 (14)
C7···C12iii3.5121 (18)H14···H312.25 (3)
C7···C13iii3.4649 (19)H14···C4iv2.938 (16)
C7···C1iv3.4250 (18)H14'···C4x3.059 (15)
C7···C8iii3.5955 (18)H14'···H102.35 (2)
C8···C5iv3.3332 (18)H14"···N12.900 (15)
C8···C4iv3.4962 (18)H14"···H312.40 (3)
C8···C7iii3.5955 (18)H14"···O1ii2.633 (14)
C9···C2iii3.4592 (18)H14"···C1iii3.048 (16)
C9···C4iv3.4797 (19)H15···H5viii2.57 (2)
C11···C6iii3.4209 (19)H15···H102.46 (2)
C12···C7iii3.5121 (18)H15'···H5viii2.59 (2)
C12···O2v3.4092 (14)H15"···C5iii2.98 (2)
C12···C6iii3.4839 (19)H21···O22.340 (17)
C13···C5iv3.5694 (19)H21···C13i2.99 (2)
C13···C7iii3.4649 (19)H21···H13i2.46 (3)
C13···O2iii3.2538 (16)H21···O2ii2.00 (2)
C13···O1v3.3069 (14)H31···O21.72 (2)
C14···O1ii3.3713 (14)H31···C72.35 (2)
C1···H14"iii3.048 (16)H31···C142.50 (2)
C1···H132.675 (14)H31···H142.25 (3)
C4···H10vi3.015 (14)H31···H14"2.40 (3)
C6—O1—H21108.2 (11)C8—C13—C12119.90 (10)
C1—N1—C8126.62 (9)N1—C1—H1118.8 (9)
C1—N1—H31110.9 (13)C2—C1—H1118.4 (9)
C8—N1—H31122.5 (12)C2—C3—H3118.1 (9)
N1—C1—C2122.78 (10)C4—C3—H3121.0 (9)
C1—C2—C3119.73 (10)C3—C4—H4122.0 (8)
C1—C2—C7119.92 (10)C5—C4—H4118.2 (8)
C3—C2—C7120.35 (10)C4—C5—H5121.7 (9)
C2—C3—C4120.82 (10)C6—C5—H5117.5 (9)
C3—C4—C5119.78 (10)C9—C10—H10119.3 (8)
C4—C5—C6120.82 (10)C11—C10—H10118.6 (8)
O1—C6—C5119.25 (10)C11—C12—H12119.8 (9)
O1—C6—C7119.23 (10)C13—C12—H12118.9 (9)
C5—C6—C7121.50 (10)C8—C13—H13120.6 (8)
C2—C7—C6116.70 (10)C12—C13—H13119.5 (8)
O2—C7—C2122.55 (10)C9—C14—H14111.6 (8)
O2—C7—C6120.74 (9)C9—C14—H14'109.8 (9)
N1—C8—C13121.55 (9)C9—C14—H14"110.7 (8)
N1—C8—C9118.11 (9)H14—C14—H14'108.3 (13)
C9—C8—C13120.34 (10)H14—C14—H14"108.7 (13)
C8—C9—C10118.30 (9)H14'—C14—H14"107.6 (13)
C8—C9—C14121.27 (9)C11—C15—H15113.3 (11)
C10—C9—C14120.43 (9)C11—C15—H15'113.3 (10)
C9—C10—C11122.16 (10)C11—C15—H15"111.1 (10)
C10—C11—C15120.97 (10)H15—C15—H15'104.2 (14)
C10—C11—C12118.03 (10)H15—C15—H15"107.9 (18)
C12—C11—C15120.97 (10)H15'—C15—H15"106.4 (14)
C11—C12—C13121.25 (10)
C8—N1—C1—C2179.91 (12)O1—C6—C7—C2179.47 (11)
C1—N1—C8—C9174.84 (12)C5—C6—C7—O2177.99 (12)
C1—N1—C8—C135.77 (19)C5—C6—C7—C21.19 (18)
N1—C1—C2—C3179.77 (12)N1—C8—C9—C10179.26 (11)
N1—C1—C2—C70.87 (19)N1—C8—C9—C141.44 (18)
C1—C2—C3—C4177.46 (12)C13—C8—C9—C101.34 (18)
C7—C2—C3—C41.44 (19)C13—C8—C9—C14177.96 (12)
C1—C2—C7—O20.84 (19)N1—C8—C13—C12179.40 (12)
C1—C2—C7—C6178.32 (11)C9—C8—C13—C120.0 (2)
C3—C2—C7—O2179.74 (12)C8—C9—C10—C111.45 (19)
C3—C2—C7—C60.58 (18)C14—C9—C10—C11177.87 (12)
C2—C3—C4—C50.53 (19)C9—C10—C11—C120.20 (19)
C3—C4—C5—C61.26 (19)C9—C10—C11—C15177.81 (12)
C4—C5—C6—O1179.58 (12)C10—C11—C12—C131.2 (2)
C4—C5—C6—C72.1 (2)C15—C11—C12—C13179.20 (12)
O1—C6—C7—O20.29 (18)C11—C12—C13—C81.3 (2)
Symmetry codes: (i) x, y+1, z; (ii) x, y+2, z+1; (iii) x, y+1, z+1; (iv) x+1, y+1, z+1; (v) x, y1, z; (vi) x, y, z+1; (vii) x+1, y, z+1; (viii) x, y1, z1; (ix) x, y+1, z+1; (x) x, y, z1; (xi) x, y+1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H21···O20.85 (2)2.340 (17)2.7674 (12)111.3 (12)
O1—H21···O2ii0.85 (2)2.00 (2)2.7320 (13)143.4 (15)
N1—H31···O21.00 (2)1.72 (2)2.5873 (12)142.7 (18)
C13—H13···O1v0.980 (14)2.557 (14)3.3069 (14)133.3 (13)
Symmetry codes: (ii) x, y+2, z+1; (v) x, y1, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
O1—H21···O20.85 (2)2.340 (17)2.7674 (12)111.3 (12)
O1—H21···O2i0.85 (2)2.00 (2)2.7320 (13)143.4 (15)
N1—H31···O21.00 (2)1.72 (2)2.5873 (12)142.7 (18)
C13—H13···O1ii0.980 (14)2.557 (14)3.3069 (14)133.3 (13)
Symmetry codes: (i) x, y+2, z+1; (ii) x, y1, z.
Acknowledgements top

SS thanks the HEC (Higher Education Commission), Islamabad, for a fellowship (PIN No. 042–111889-PS2–104).

references
References top

Blagus, A. & Kaitner, B. (2011). Acta Cryst. E67, o2958–o2959.

Bruker (2006). SMART, SAINT-Plus and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.

Burla, M. C., Caliandro, R., Camalli, M., Carrozzini, B., Cascarano, G. L., De Caro, L., Giacovazzo, C., Polidori, G. & Spagna, R. (2005). J. Appl. Cryst. 38, 381–388.

Meetsma, A. (2006). Extended version of the program PLUTO. University of Groningen, The Netherlands. Unpublished.

Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122.

Shuja, S., Ali, S., Khalid, N. & Meetsma, A. (2007). Acta Cryst. E63, o3162–o3164.

Spek, A. L. (2009). Acta Cryst. D65, 148–155.