organic compounds
2,2′-(4-{[(E)-4-Methoxybenzylidene]amino}phenylimino)diethanol
aKey Laboratory of Synthetic and Natural Chemistry of the Ministry of Education, College of Chemistry and Material Science, The North-West University of Xi'an, Taibai Bei Avenue 229, Xi'an 710069, Shaanxi Province, People's Republic of China
*Correspondence e-mail: yangbq@nwu.edu.cn
In the title compound, C18H22N2O3, the dihedral angle between the aromatic rings is 3.9 (2)°. Both H atoms of the hydroxy groups are involved in intermolecular O—H⋯O hydrogen bonding. In the this hydrogen bonding assembles molecules into chains of 21 symmetry extending parallel to the b axis. The almost planar (within 0.09 and 0.06 Å) 4-CH3O–C6H4–CH=N–C6H4– groups are oriented outwards the twofold screw axis.
Related literature
For practical interest in Shiff bases of general type p-R′–C6H4–CH=N–C6H4–R′′-p in various areas, see: von König et al. (1982); Haldavanekar et al. (2009); Ferlin et al. (2004); Lewis et al. (2009). For the only two structurally characterized compounds of this type with R′′ = N(alkyl)2, see: Nagao et al. (2002); Nakai et al. (1976). For 4-[(E)-({4-[bis(2-hydroxyethyl)amino]phenyl}imino)methyl]phenol, C17H20N2O3, see: Liu et al. (2010). For a description of preparation routines, see: Cho & Park (1997); Ferlin et al. (2004); von König et al. (1982). For a description of the Cambridge Structural Database, see: Allen (2002).
Experimental
Crystal data
|
Refinement
|
Data collection: APEX2 (Bruker, 2007); cell SAINT (Bruker, 2007); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: SHELXTL and OLEX2.
Supporting information
https://doi.org/10.1107/S1600536810028035/im2204sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: https://doi.org/10.1107/S1600536810028035/im2204Isup2.hkl
1-Chloro-4-nitrobenzene, 4-methoxy-benzaldehyde, 2-(2-hydroxy-ethylamino)-ethanol, ammonium formate, 10% Pd/C catalyst and solvents were purchased from Sinopharm Chemical Reagent and Tianjin Fuyu Chemical companies. 2-[(2-Hydroxy-ethyl)-(4-nitro-phenyl)-amino]-ethanol was prepared as described by Cho & Park (1997) and Ferlin et al. (2004). Reduction of the nitro-group was carried out as described by Lewis et al. (2009). Schiff-base preparation was done by a modification of the procedure reported by von König et al. (1982).
Procedure: 1-chloro-4-nitrobenzene (15.76 g, 0.10 mol) was dissolved in 2-(2-hydroxy-ethylamino)-ethanol (50 ml). The reaction mixture was heated to 393 K for 10 h and then cooled down to room temperature. Precipitating crude 2-[(2-Hydroxy-ethyl)-(4-nitro-phenyl)-amino]-ethanol was filtered off, dried in vacuum and recrystallized from a minimal amount of hot ethanol. Yield 11.54 g (51%). 2-[(2-Hydroxy-ethyl)-(4-nitro-phenyl)-amino]-ethanol (8.15 g, 0.036 mol) was then dissolved in MeOH (50 ml). To this solution, HCOONH4 (0.216 mol) and 10% Pd/C (0.6 g) were added and the slurry was stirred at 293 K for 30 min. On removal of the catalyst by filtration, the filtrate was placed into a N2-flushed flask containing 1 ml of acetic acid and an equimolar (0.036 mol) amount of 4-methoxybenzaldehyde (0.036 mol) was added dropwise at 333 K during 30 min. The reaction mixture was kept at the same temperature for additional 30 min, cooled down to 273 K and ice-cold water (200 ml) was added. The precipitated yellow solid was collected by filtration, washed with water, dried under reduced pressure and, finally, re-crystallized by a slow evaporation of its methanolic solution in air at 293 K. Yield 95%, m.p. 402 K. 1H NMR (I) δ: 8.50 (s, 1 H, CH═N), 6.78–7.83 (m, 8 H, C6H4), 3.31, 3.72 (both t, 4 H and 4 H, 3JHH = 7.2 Hz, CH2), 3.86 (s, 3H, CH3). A ingle crystal of (I) suitable for X-ray was picked up directly from the obtained material.
All non-H atoms were refined anisotropically. H atoms except of H7 and OH were treated as riding atoms with distances of C—H = 0.96 (CH3), 0.97 (CH2), 0.93 Å (CArH), and Uiso(H) = 1.5 Ueq(C), 1.2 Ueq(C), and 1.2 Ueq(C), respectively. Atoms H7 and OH hydrogen atoms were found from difference Fourier syntheses and refined isotropically. Despite the fact that an achiral compound (I) crystallizes in a α radiation with no atoms heavier than oxygen) and the for (I) was preformed with the Friedel opposites merged (MERG 3 instruction).
P21, neither the determination nor approval of the inversion was possible due to evident reasons (Mo-KShiff bases of the general type p-R'–C6H4–CH=N–C6H4–R"-p are well-known compounds that find practical application in various areas [photography (for instance, see von König et al., 1982), medicinal and pharmaceutical chemistry (for instance, see Haldavanekar et al., 2009; Ferlin et al., 2004; Lewis et al., 2009)]. Recently, we were interested in preparation of a series of 2-((2-hydroxy-ethyl)-{4-[(benzylidene)-amino]-phenyl}-amino)-ethanols as intermediates for their further conversion into paracyclophanes. This way, 2-((2-hydroxy-ethyl)-{4-[((1E)4-methoxy-benzylidene)-amino]-phenyl}-amino)-ethanol , C18H22N2O3, (I), and 4-({(E)-4-[bis-(2-hydroxy-ethyl)-amino]-phenylimino}-methyl)-phenol , C17H20N2O3, [II; Liu et al. (2010)] were prepared by a condensation reaction between 2-[(4-Amino-phenyl)-(2-hydroxy-ethyl)-amino]-ethanol and 4-methoxy- or 4-hydroxybenzaldehyde, respectively.
Despite of the fact that structurally characterized Shiff bases of general type p-R'–C6H4–CH=N–C6H4–R"-p are well presented in the Cambridge Structural Database [CSD; Version 5.27, release February 2009; Allen, 2002; 128 entries, 173 fragments], among them there are only two compounds with R" = N(alkyl)2 [namely: R' = H, R'' = NEt2 (Nagao et al., 2002) and R' = NO2, R" = NMe2 (Nakai et al., 1976)]. From this viewpoint, X-ray single crystal study of (I) presents a certain descriptive interest.
The
of (I) is shown in Fig. 1. Except of dihedral angle C7–N1–C8–C9, asymmetric units of (I) and its sister compound [II; Liu et al. (2010)] show almost identical geometries (see Supplementary material). Bond lengths and angles as well as the C4–C7–N1–C8 torsion angle match well with the reported average values for p-R'–C6H4–CH=N–C6H4–R"-p [analysis of the Cambridge Structural Database (CSD); Version 5.27, release February 2009; Allen, 2002; 128 entries, 173 fragments]. Fragments O1/C1—C7/N1/C18 and C8—C13/N2/C14/C16 are almost planar [within 0.09 and 0.06 Å]. The amino N2 atom is also in a planar environment [sum of the valent angles 359.9 (3)°] which most frequenty the case for aryldialkylamines (range from 317.6 to 360.0°, average value 359.0°).In (I), both hydroxy H-atoms are involved into hydrogen bonding [for the H-bonds lengths and angles values, see the Table]. In (I), molecules along with their equivalents generated by a 21 screw axis form a one-dimensional infinite chain stretched along the b-axis. Organic moieties are oriented outwards the corresponding screw axis (see Fig. 2). These one-dimensional assemblies do not interact with their equivalent neighbours by any hydrogen bonds and are just stacked one by another. This results in an evident flattening of the entire CH3O—C6H4C(H)=NC6H4 moieties for the inter-chain repulsion diminishing.
packing of (I) differs markedly from that of (II) (Liu et al., 2010)).For practical interest in Shiff bases of general type p-R'–C6H4–CH=N–C6H4–R"-p in various areas, see: von König et al. (1982); Haldavanekar et al. (2009); Ferlin et al. (2004); Lewis et al. (2009). For the only two structurally characterized compounds of this type with R" = N(alkyl)2, see: Nagao et al. (2002); Nakai et al. (1976). For 4-[(E)-({4-[bis(2-hydroxyethyl)amino]phenyl}imino)methyl]phenol, C17H20N2O3, see: Liu et al. (2010). For a description of preparation routines, see: Cho & Park (1997); Ferlin et al. (2004); von König et al. (1982). For a description of the Cambridge Structural Database, see: Allen (2002).
Data collection: APEX2 (Bruker, 2007); cell
SAINT (Bruker, 2007); data reduction: SAINT (Bruker, 2007); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008) and OLEX2 (Dolomanov et al., 2009); software used to prepare material for publication: SHELXTL97 (Sheldrick, 2008) and OLEX2 (Dolomanov et al., 2009).C18H22N2O3 | F(000) = 336 |
Mr = 314.38 | Dx = 1.300 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 2324 reflections |
a = 5.3795 (9) Å | θ = 2.0–28.2° |
b = 8.0585 (14) Å | µ = 0.09 mm−1 |
c = 18.531 (3) Å | T = 296 K |
β = 91.168 (2)° | Block, yellow |
V = 803.2 (2) Å3 | 0.24 × 0.13 × 0.07 mm |
Z = 2 |
Bruker SMART APEXII diffractometer | 1541 independent reflections |
Radiation source: fine-focus sealed tube | 1225 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.037 |
Detector resolution: 8.333 pixels mm-1 | θmax = 25.1°, θmin = 2.2° |
phi and ω scans | h = −5→6 |
Absorption correction: multi-scan (TWINABS; Sheldrick, 1996) | k = −9→9 |
Tmin = 0.979, Tmax = 0.994 | l = −22→20 |
4036 measured reflections |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.038 | H atoms treated by a mixture of independent and constrained refinement |
wR(F2) = 0.108 | w = 1/[σ2(Fo2) + (0.0702P)2] where P = (Fo2 + 2Fc2)/3' |
S = 1.06 | (Δ/σ)max < 0.001 |
1541 reflections | Δρmax = 0.17 e Å−3 |
222 parameters | Δρmin = −0.13 e Å−3 |
1 restraint | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.028 (7) |
C18H22N2O3 | V = 803.2 (2) Å3 |
Mr = 314.38 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 5.3795 (9) Å | µ = 0.09 mm−1 |
b = 8.0585 (14) Å | T = 296 K |
c = 18.531 (3) Å | 0.24 × 0.13 × 0.07 mm |
β = 91.168 (2)° |
Bruker SMART APEXII diffractometer | 1541 independent reflections |
Absorption correction: multi-scan (TWINABS; Sheldrick, 1996) | 1225 reflections with I > 2σ(I) |
Tmin = 0.979, Tmax = 0.994 | Rint = 0.037 |
4036 measured reflections |
R[F2 > 2σ(F2)] = 0.038 | 1 restraint |
wR(F2) = 0.108 | H atoms treated by a mixture of independent and constrained refinement |
S = 1.06 | Δρmax = 0.17 e Å−3 |
1541 reflections | Δρmin = −0.13 e Å−3 |
222 parameters |
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 > 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 F^2^ 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 | ||
O1 | 0.5558 (4) | 0.2396 (3) | −0.24985 (10) | 0.0589 (6) | |
O2 | −0.3959 (5) | −0.0877 (3) | 0.43576 (14) | 0.0712 (8) | |
O3 | −0.4849 (5) | 0.5749 (3) | 0.43870 (13) | 0.0628 (7) | |
N1 | 0.1089 (5) | 0.2496 (3) | 0.06704 (12) | 0.0469 (6) | |
N2 | −0.1774 (5) | 0.2079 (3) | 0.35822 (11) | 0.0515 (7) | |
C1 | 0.5101 (5) | 0.2264 (4) | −0.17743 (13) | 0.0424 (7) | |
C2 | 0.6533 (6) | 0.1361 (4) | −0.12960 (15) | 0.0485 (7) | |
H2A | 0.7947 | 0.0811 | −0.1450 | 0.058* | |
C3 | 0.5840 (6) | 0.1278 (4) | −0.05799 (15) | 0.0476 (7) | |
H3A | 0.6830 | 0.0680 | −0.0255 | 0.057* | |
C4 | 0.3737 (6) | 0.2052 (4) | −0.03335 (14) | 0.0427 (7) | |
C5 | 0.2341 (5) | 0.3012 (4) | −0.08283 (14) | 0.0466 (7) | |
H5 | 0.0939 | 0.3577 | −0.0675 | 0.056* | |
C6 | 0.3029 (6) | 0.3123 (4) | −0.15342 (15) | 0.0487 (8) | |
H6 | 0.2106 | 0.3776 | −0.1855 | 0.058* | |
C7 | 0.3019 (6) | 0.1862 (4) | 0.04166 (16) | 0.0494 (8) | |
C8 | 0.0474 (5) | 0.2305 (4) | 0.14073 (14) | 0.0416 (7) | |
C9 | 0.1730 (6) | 0.1309 (4) | 0.19122 (15) | 0.0471 (7) | |
H9 | 0.3095 | 0.0692 | 0.1769 | 0.057* | |
C10 | 0.0986 (5) | 0.1223 (4) | 0.26191 (15) | 0.0434 (7) | |
H10 | 0.1849 | 0.0537 | 0.2940 | 0.052* | |
C11 | −0.1033 (5) | 0.2140 (3) | 0.28648 (14) | 0.0405 (7) | |
C12 | −0.2278 (5) | 0.3138 (4) | 0.23556 (14) | 0.0474 (7) | |
H12 | −0.3625 | 0.3774 | 0.2498 | 0.057* | |
C13 | −0.1543 (5) | 0.3197 (4) | 0.16480 (14) | 0.0478 (7) | |
H13 | −0.2432 | 0.3857 | 0.1322 | 0.057* | |
C14 | −0.0579 (6) | 0.0964 (4) | 0.40875 (15) | 0.0508 (8) | |
H14B | −0.0800 | 0.1388 | 0.4572 | 0.061* | |
H14A | 0.1190 | 0.0952 | 0.3997 | 0.061* | |
C15 | −0.1541 (6) | −0.0790 (4) | 0.40534 (16) | 0.0562 (8) | |
H15A | −0.1624 | −0.1158 | 0.3555 | 0.067* | |
H15B | −0.0413 | −0.1519 | 0.4318 | 0.067* | |
C16 | −0.3805 (6) | 0.3088 (4) | 0.38402 (15) | 0.0488 (8) | |
H16B | −0.4516 | 0.2560 | 0.4259 | 0.059* | |
H16A | −0.5092 | 0.3158 | 0.3467 | 0.059* | |
C17 | −0.2951 (6) | 0.4822 (4) | 0.40415 (17) | 0.0547 (8) | |
H17B | −0.1508 | 0.4747 | 0.4362 | 0.066* | |
H17A | −0.2457 | 0.5403 | 0.3609 | 0.066* | |
C18 | 0.7676 (6) | 0.1549 (5) | −0.27577 (17) | 0.0647 (10) | |
H18C | 0.7739 | 0.1667 | −0.3273 | 0.097* | |
H18A | 0.7567 | 0.0394 | −0.2636 | 0.097* | |
H18B | 0.9154 | 0.2013 | −0.2540 | 0.097* | |
H2 | −0.428 (9) | −0.200 (7) | 0.438 (2) | 0.116 (18)* | |
H3 | −0.542 (8) | 0.522 (6) | 0.473 (2) | 0.094 (16)* | |
H7 | 0.417 (7) | 0.122 (5) | 0.072 (2) | 0.070 (10)* |
U11 | U22 | U33 | U12 | U13 | U23 | |
O1 | 0.0670 (15) | 0.0725 (15) | 0.0376 (10) | 0.0002 (13) | 0.0076 (10) | 0.0024 (11) |
O2 | 0.0969 (19) | 0.0440 (14) | 0.0745 (16) | −0.0085 (13) | 0.0465 (14) | −0.0068 (12) |
O3 | 0.1009 (19) | 0.0386 (12) | 0.0500 (13) | 0.0089 (12) | 0.0287 (12) | 0.0006 (11) |
N1 | 0.0500 (15) | 0.0515 (15) | 0.0395 (12) | 0.0011 (13) | 0.0089 (11) | −0.0011 (12) |
N2 | 0.0741 (18) | 0.0424 (14) | 0.0388 (13) | 0.0072 (14) | 0.0176 (12) | 0.0014 (11) |
C1 | 0.0462 (17) | 0.0451 (16) | 0.0362 (14) | −0.0077 (15) | 0.0069 (12) | −0.0046 (14) |
C2 | 0.0472 (17) | 0.0520 (18) | 0.0469 (16) | 0.0042 (15) | 0.0118 (13) | −0.0010 (15) |
C3 | 0.0505 (17) | 0.0494 (18) | 0.0431 (16) | 0.0040 (15) | 0.0041 (13) | 0.0035 (14) |
C4 | 0.0463 (17) | 0.0440 (18) | 0.0380 (14) | −0.0032 (14) | 0.0044 (12) | −0.0022 (13) |
C5 | 0.0446 (16) | 0.0497 (18) | 0.0454 (16) | 0.0039 (15) | 0.0030 (13) | −0.0061 (14) |
C6 | 0.0501 (17) | 0.0525 (18) | 0.0431 (15) | 0.0013 (16) | −0.0041 (13) | 0.0026 (15) |
C7 | 0.055 (2) | 0.053 (2) | 0.0408 (16) | 0.0006 (17) | 0.0054 (15) | −0.0003 (14) |
C8 | 0.0459 (16) | 0.0408 (16) | 0.0384 (14) | −0.0046 (14) | 0.0062 (12) | −0.0015 (14) |
C9 | 0.0505 (17) | 0.0436 (17) | 0.0477 (16) | 0.0027 (15) | 0.0124 (13) | −0.0021 (14) |
C10 | 0.0499 (17) | 0.0405 (16) | 0.0400 (15) | 0.0022 (14) | 0.0063 (13) | 0.0026 (13) |
C11 | 0.0524 (18) | 0.0319 (15) | 0.0375 (14) | −0.0050 (13) | 0.0077 (12) | −0.0007 (12) |
C12 | 0.0472 (17) | 0.0478 (17) | 0.0477 (16) | 0.0060 (15) | 0.0129 (13) | −0.0021 (15) |
C13 | 0.0499 (18) | 0.0497 (17) | 0.0439 (16) | 0.0055 (16) | 0.0029 (13) | 0.0042 (15) |
C14 | 0.0660 (19) | 0.0506 (19) | 0.0360 (14) | −0.0014 (16) | 0.0083 (13) | 0.0003 (14) |
C15 | 0.074 (2) | 0.0450 (18) | 0.0506 (17) | 0.0049 (17) | 0.0215 (15) | 0.0067 (15) |
C16 | 0.064 (2) | 0.0413 (17) | 0.0423 (15) | −0.0047 (15) | 0.0172 (14) | −0.0018 (14) |
C17 | 0.074 (2) | 0.0420 (17) | 0.0483 (16) | −0.0061 (16) | 0.0156 (15) | −0.0042 (14) |
C18 | 0.063 (2) | 0.084 (3) | 0.0475 (18) | −0.010 (2) | 0.0156 (16) | −0.0099 (18) |
O1—C1 | 1.373 (3) | C8—C13 | 1.383 (4) |
O1—C18 | 1.420 (4) | C8—C9 | 1.396 (4) |
O2—C15 | 1.430 (4) | C9—C10 | 1.379 (4) |
O2—H2 | 0.92 (5) | C9—H9 | 0.9300 |
O3—C17 | 1.427 (4) | C10—C11 | 1.398 (4) |
O3—H3 | 0.82 (5) | C10—H10 | 0.9300 |
N1—C7 | 1.257 (4) | C11—C12 | 1.400 (4) |
N1—C8 | 1.420 (3) | C12—C13 | 1.378 (4) |
N2—C11 | 1.397 (3) | C12—H12 | 0.9300 |
N2—C14 | 1.440 (4) | C13—H13 | 0.9300 |
N2—C16 | 1.451 (4) | C14—C15 | 1.506 (5) |
C1—C2 | 1.372 (4) | C14—H14B | 0.9700 |
C1—C6 | 1.393 (4) | C14—H14A | 0.9700 |
C2—C3 | 1.387 (4) | C15—H15A | 0.9700 |
C2—H2A | 0.9300 | C15—H15B | 0.9700 |
C3—C4 | 1.378 (4) | C16—C17 | 1.515 (4) |
C3—H3A | 0.9300 | C16—H16B | 0.9700 |
C4—C5 | 1.405 (4) | C16—H16A | 0.9700 |
C4—C7 | 1.458 (4) | C17—H17B | 0.9700 |
C5—C6 | 1.369 (4) | C17—H17A | 0.9700 |
C5—H5 | 0.9300 | C18—H18C | 0.9600 |
C6—H6 | 0.9300 | C18—H18A | 0.9600 |
C7—H7 | 0.98 (4) | C18—H18B | 0.9600 |
C1—O1—C18 | 117.0 (2) | N2—C11—C12 | 121.3 (2) |
C15—O2—H2 | 104 (3) | C10—C11—C12 | 116.6 (2) |
C17—O3—H3 | 111 (3) | C13—C12—C11 | 121.2 (3) |
C7—N1—C8 | 121.7 (3) | C13—C12—H12 | 119.4 |
C11—N2—C14 | 120.6 (2) | C11—C12—H12 | 119.4 |
C11—N2—C16 | 121.7 (2) | C12—C13—C8 | 122.1 (3) |
C14—N2—C16 | 117.7 (2) | C12—C13—H13 | 119.0 |
C2—C1—O1 | 124.3 (3) | C8—C13—H13 | 119.0 |
C2—C1—C6 | 120.0 (2) | N2—C14—C15 | 114.2 (3) |
O1—C1—C6 | 115.7 (2) | N2—C14—H14B | 108.7 |
C1—C2—C3 | 119.0 (3) | C15—C14—H14B | 108.7 |
C1—C2—H2A | 120.5 | N2—C14—H14A | 108.7 |
C3—C2—H2A | 120.5 | C15—C14—H14A | 108.7 |
C4—C3—C2 | 122.2 (3) | H14B—C14—H14A | 107.6 |
C4—C3—H3A | 118.9 | O2—C15—C14 | 110.1 (3) |
C2—C3—H3A | 118.9 | O2—C15—H15A | 109.6 |
C3—C4—C5 | 117.7 (2) | C14—C15—H15A | 109.6 |
C3—C4—C7 | 120.2 (3) | O2—C15—H15B | 109.6 |
C5—C4—C7 | 122.1 (3) | C14—C15—H15B | 109.6 |
C6—C5—C4 | 120.5 (3) | H15A—C15—H15B | 108.1 |
C6—C5—H5 | 119.7 | N2—C16—C17 | 111.8 (3) |
C4—C5—H5 | 119.7 | N2—C16—H16B | 109.3 |
C5—C6—C1 | 120.4 (3) | C17—C16—H16B | 109.3 |
C5—C6—H6 | 119.8 | N2—C16—H16A | 109.3 |
C1—C6—H6 | 119.8 | C17—C16—H16A | 109.3 |
N1—C7—C4 | 123.4 (3) | H16B—C16—H16A | 107.9 |
N1—C7—H7 | 121 (2) | O3—C17—C16 | 112.2 (3) |
C4—C7—H7 | 115 (2) | O3—C17—H17B | 109.2 |
C13—C8—C9 | 117.0 (2) | C16—C17—H17B | 109.2 |
C13—C8—N1 | 117.0 (3) | O3—C17—H17A | 109.2 |
C9—C8—N1 | 126.0 (3) | C16—C17—H17A | 109.2 |
C10—C9—C8 | 121.3 (3) | H17B—C17—H17A | 107.9 |
C10—C9—H9 | 119.4 | O1—C18—H18C | 109.5 |
C8—C9—H9 | 119.4 | O1—C18—H18A | 109.5 |
C9—C10—C11 | 121.7 (3) | H18C—C18—H18A | 109.5 |
C9—C10—H10 | 119.2 | O1—C18—H18B | 109.5 |
C11—C10—H10 | 119.2 | H18C—C18—H18B | 109.5 |
N2—C11—C10 | 122.0 (3) | H18A—C18—H18B | 109.5 |
C18—O1—C1—C2 | −0.8 (4) | C8—C9—C10—C11 | −0.8 (5) |
C18—O1—C1—C6 | 179.3 (3) | C14—N2—C11—C10 | −4.5 (4) |
O1—C1—C2—C3 | −178.0 (3) | C16—N2—C11—C10 | 177.3 (3) |
C6—C1—C2—C3 | 1.9 (5) | C14—N2—C11—C12 | 175.9 (3) |
C1—C2—C3—C4 | 1.1 (5) | C16—N2—C11—C12 | −2.3 (4) |
C2—C3—C4—C5 | −3.0 (5) | C9—C10—C11—N2 | −179.0 (3) |
C2—C3—C4—C7 | 177.0 (3) | C9—C10—C11—C12 | 0.6 (4) |
C3—C4—C5—C6 | 1.9 (4) | N2—C11—C12—C13 | −180.0 (3) |
C7—C4—C5—C6 | −178.0 (3) | C10—C11—C12—C13 | 0.4 (4) |
C4—C5—C6—C1 | 1.0 (4) | C11—C12—C13—C8 | −1.2 (5) |
C2—C1—C6—C5 | −3.0 (5) | C9—C8—C13—C12 | 1.0 (4) |
O1—C1—C6—C5 | 177.0 (3) | N1—C8—C13—C12 | −178.5 (3) |
C8—N1—C7—C4 | −179.0 (3) | C11—N2—C14—C15 | −81.9 (3) |
C3—C4—C7—N1 | −178.0 (3) | C16—N2—C14—C15 | 96.3 (3) |
C5—C4—C7—N1 | 1.9 (5) | N2—C14—C15—O2 | −72.9 (3) |
C7—N1—C8—C13 | 173.3 (3) | C11—N2—C16—C17 | −83.9 (3) |
C7—N1—C8—C9 | −6.2 (5) | C14—N2—C16—C17 | 97.9 (3) |
C13—C8—C9—C10 | 0.0 (4) | N2—C16—C17—O3 | −172.0 (2) |
N1—C8—C9—C10 | 179.5 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O3i | 0.95 (5) | 1.84 (6) | 2.762 (3) | 177 (4) |
O3—H3···O2ii | 0.82 (4) | 1.95 (4) | 2.757 (4) | 166 (4) |
Symmetry codes: (i) x, y−1, z; (ii) −x−1, y+1/2, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C18H22N2O3 |
Mr | 314.38 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 296 |
a, b, c (Å) | 5.3795 (9), 8.0585 (14), 18.531 (3) |
β (°) | 91.168 (2) |
V (Å3) | 803.2 (2) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 0.09 |
Crystal size (mm) | 0.24 × 0.13 × 0.07 |
Data collection | |
Diffractometer | Bruker SMART APEXII |
Absorption correction | Multi-scan (TWINABS; Sheldrick, 1996) |
Tmin, Tmax | 0.979, 0.994 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 4036, 1541, 1225 |
Rint | 0.037 |
(sin θ/λ)max (Å−1) | 0.597 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.038, 0.108, 1.06 |
No. of reflections | 1541 |
No. of parameters | 222 |
No. of restraints | 1 |
H-atom treatment | H atoms treated by a mixture of independent and constrained refinement |
Δρmax, Δρmin (e Å−3) | 0.17, −0.13 |
Computer programs: APEX2 (Bruker, 2007), SAINT (Bruker, 2007), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008) and OLEX2 (Dolomanov et al., 2009), SHELXTL97 (Sheldrick, 2008) and OLEX2 (Dolomanov et al., 2009).
D—H···A | D—H | H···A | D···A | D—H···A |
O2—H2···O3i | 0.95 (5) | 1.84 (6) | 2.762 (3) | 177 (4) |
O3—H3···O2ii | 0.82 (4) | 1.95 (4) | 2.757 (4) | 166 (4) |
Symmetry codes: (i) x, y−1, z; (ii) −x−1, y+1/2, −z+1. |
Acknowledgements
Financial support from the National Natural Science Foundation of China (project No. 20972125) is gratefully acknowledged. The authors are grateful to Mr Sun Wei for his help in measuring the 1H NMR spectra.
References
Allen, F. H. (2002). Acta Cryst. B58, 380–388. Web of Science CSD CrossRef CAS IUCr Journals Google Scholar
Bruker (2007). APEX2 and SAINT. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Cho, Y. H. & Park, J. C. (1997). Tetrahedron Lett. 38, 8331–8334. CrossRef CAS Web of Science Google Scholar
Dolomanov, O. V., Bourhis, L. J., Gildea, R. J., Howard, J. A. K. & Puschmann, H. (2009). J. Appl. Cryst. 42, 339–341. Web of Science CrossRef CAS IUCr Journals Google Scholar
Ferlin, M. G., Dalla Via, L. & Gia, O. M. (2004). Bioorg. Med. Chem. 12, 771–777. Web of Science CrossRef PubMed CAS Google Scholar
Haldavanekar, V., Prabhu, M., Dharmaraj, R. & Kankan, R. N. (2009). Process for Synthesis of Arformoterol. WO Patent 2009147383 A1. Google Scholar
König, A. von, Moll, F. & Rosenhahn, L. (1982). Photographic Material, Process for the Production Thereof and Process for Production of Photographic Images. US Patent 4358531. Google Scholar
Lewis, J., Matteucci, M., Chen, T. & Jiao, H. (2009). Hypoxia Activated Drugs of Nitrogen Mustard Alkylators as Anticancer Agents and Their Preparation. WO Patent 2009140553 A2. Google Scholar
Liu, X., Yang, B. & Borzov, M. V. (2010). Acta Cryst. E66, o1646. Web of Science CSD CrossRef IUCr Journals Google Scholar
Nagao, Y., Kimura, F., Kozawa, K. & Uchida, T. (2002). Shikizai Kyokaishi, 75, 415–420. CAS Google Scholar
Nakai, H., Shiro, M., Emuzi, K., Sakata, S. & Kubota, T. (1976). Acta Cryst. B32, 1827–1833. CSD CrossRef CAS IUCr Journals Web of Science Google Scholar
Sheldrick, G. M. (1996). SADABS. University of Göttingen, Germany. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
This is an open-access article distributed under the terms of the Creative Commons Attribution (CC-BY) Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.
Shiff bases of the general type p-R'–C6H4–CH=N–C6H4–R"-p are well-known compounds that find practical application in various areas [photography (for instance, see von König et al., 1982), medicinal and pharmaceutical chemistry (for instance, see Haldavanekar et al., 2009; Ferlin et al., 2004; Lewis et al., 2009)]. Recently, we were interested in preparation of a series of 2-((2-hydroxy-ethyl)-{4-[(benzylidene)-amino]-phenyl}-amino)-ethanols as intermediates for their further conversion into paracyclophanes. This way, 2-((2-hydroxy-ethyl)-{4-[((1E)4-methoxy-benzylidene)-amino]-phenyl}-amino)-ethanol , C18H22N2O3, (I), and 4-({(E)-4-[bis-(2-hydroxy-ethyl)-amino]-phenylimino}-methyl)-phenol , C17H20N2O3, [II; Liu et al. (2010)] were prepared by a condensation reaction between 2-[(4-Amino-phenyl)-(2-hydroxy-ethyl)-amino]-ethanol and 4-methoxy- or 4-hydroxybenzaldehyde, respectively.
Despite of the fact that structurally characterized Shiff bases of general type p-R'–C6H4–CH=N–C6H4–R"-p are well presented in the Cambridge Structural Database [CSD; Version 5.27, release February 2009; Allen, 2002; 128 entries, 173 fragments], among them there are only two compounds with R" = N(alkyl)2 [namely: R' = H, R'' = NEt2 (Nagao et al., 2002) and R' = NO2, R" = NMe2 (Nakai et al., 1976)]. From this viewpoint, X-ray single crystal study of (I) presents a certain descriptive interest.
The asymmetric unit of (I) is shown in Fig. 1. Except of dihedral angle C7–N1–C8–C9, asymmetric units of (I) and its sister compound [II; Liu et al. (2010)] show almost identical geometries (see Supplementary material). Bond lengths and angles as well as the C4–C7–N1–C8 torsion angle match well with the reported average values for p-R'–C6H4–CH=N–C6H4–R"-p [analysis of the Cambridge Structural Database (CSD); Version 5.27, release February 2009; Allen, 2002; 128 entries, 173 fragments]. Fragments O1/C1—C7/N1/C18 and C8—C13/N2/C14/C16 are almost planar [within 0.09 and 0.06 Å]. The amino N2 atom is also in a planar environment [sum of the valent angles 359.9 (3)°] which most frequenty the case for aryldialkylamines (range from 317.6 to 360.0°, average value 359.0°).
In (I), both hydroxy H-atoms are involved into hydrogen bonding [for the H-bonds lengths and angles values, see the Table]. In (I), molecules along with their equivalents generated by a 21 screw axis form a one-dimensional infinite chain stretched along the b-axis. Organic moieties are oriented outwards the corresponding screw axis (see Fig. 2). These one-dimensional assemblies do not interact with their equivalent neighbours by any hydrogen bonds and are just stacked one by another. This results in an evident flattening of the entire CH3O—C6H4C(H)=NC6H4 moieties for the inter-chain repulsion diminishing. Crystal lattice packing of (I) differs markedly from that of (II) (Liu et al., 2010)).