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Acta Cryst. (2011). E67, o1866-o1867    [ doi:10.1107/S1600536811025128 ]

Benzyl N-(2-hydroxy-1-{N'-[(1E)-2-hydroxybenzylidene]hydrazinecarbonyl}ethyl)carbamate

E. R. T. Tiekink, M. V. N. de Souza, A. C. Pinheiro, S. M. S. V. Wardell and J. L. Wardell

Abstract top

The molecule of the title compound, C18H19N3O5, adopts a curved arrangement with the terminal benzene rings lying to the same side. The hydroxylbenzene ring is close to coplanar with the adjacent hydrazine residue [dihedral angle = 11.14 (12)°], an observation which correlates with the presence of an intramolecular O-H...N hydrogen bond. The benzyl ring forms a dihedral angle of 50.84 (13)° with the adjacent carbamate group. A twist in the molecule, at the chiral C atom, is reflected in the dihedral angle of 80.21 (12)° formed between the amide residues. In the crystal, two-dimensional arrays in the ac plane are mediated by O-H...O and N-H...O hydrogen bonds.

Comment top

The known anti-tumour activity of L-serine derivatives (Jiao et al., 2009; Yakura et al.,2007) motivates the development of N-acylhydrazone derivatives from L-serine for anti-tumour testing (Pinheiro et al., 2010; de Souza et al., 2010; Pinheiro et al., 2011a; Pinheiro et al., 2011b, de Souza et al., 2011; Howie et al., 2011), and led to the analysis of (I).

The absolute structure of (I) could not be determined experimentally but, the assignment of the S-configuration at the C9 atom is based on a starting reagent, L-serine. The structure of (I), Fig. 1, adopts a curved conformation with both benzene rings lying to the same side of the molecule. The presence of an intramolecular O—H···N hydrogen bond ensures that the hydroxybenzene group is co-planar with the adjacent hydrazine residue with the dihedral angle between the (O2,N1,N2,C7,C8) and (C1–C6) planes being 11.14 (12) °. By contrast, the benzene ring adjacent to the carbamate residue is twisted as seen in the value of the dihedral angle formed between (O4,O5,N3,C11) and (C13–C18) of 50.84 (13) °. The dihedral angle between the two terminal benzene rings is 75.89 (19) °. The molecule is twisted about the chiral centre with the dihedral angle formed between the two amide residues, i.e. N2,C8,O2 and N3,C11,O4, being 80.21 (12) °.

Hydrogen bonds dominate the crystal packing, Table 1. Thus, the secondary hydroxyl group forms a O—H···O hydrogen bond to the hydrazine-carbonyl-O2, and accepts a N—H···.O hydrogen bond from the hydrazine-amine, leading to chains along the c axis. The carbamate-amine forms a N—H···O hydrogen bond to the carbamate-carbonyl-O4, leading to chains along the a axis. The result is the formation of a two-dimensional array in the ac plane, Fig. 2. The layers stack along the b axis, Fig. 3.

Related literature top

For background to the use of L-serine derivatives in anti-tumour therapy, see: Jiao et al. (2009); Yakura et al. (2007). For background to N-acylhydrazone derivatives from L-serine for anti-tumour testing, see: Pinheiro et al. (2010, 2011a,b); de Souza et al. (2010, 2011); Howie et al. (2011).

Experimental top

To a stirred solution of methyl (2S)-2-[(benzyloxycarbonyl)amino]-3-hydroxypropanoate (0.3 g, 1.17 mmol), prepared from (2S)-2-amino-3-hydroxypropanoate hydrochloride and benzyl chloroformate (21 ml, 0.15 mol), in ethanol (10 ml) was added N2H4.H2O (80%, 5.5 mmol). The reaction mixture was stirred for 24 h at room temperature, rotary evaporated and the residue washed with cold ethanol (3 x 10 ml) to give benzyl (1S)-2-hydrazino-1-(hydroxymethyl)-2-oxoethylcarbamate in 78% yield, which was used as such for the next stage. To a stirred solution of (S)-PhCH2OCONHCH(CH2OH)CONHNH2 (1.0 mmol) in ethanol (10 ml) at room temperature was added 2-hydroxybenzaldehyde (1.05 mmol). The reaction mixture was refluxed for 4 h, rotary evaporated and the residue purified by washing with cold ethanol (3 x 10 ml), affording the title compound, M.pt. 433 K, yield 89%. The sample for the structure determination was recrystallized from EtOH to yield colourless laths. 1H NMR (500 MHz, DMSO-d6) δ (p.p.m.): 11.79 (1H, s, NHN), 11.12 (1H, s, Ph—OH), 8.46 (1H, s, N═ CH, (E)-diastereomer), 7.52 (1H, dd, J = 7.8 and J = 1.5, H6), 7.48 (1H, d, J = 7.8, NHCH), 7.40–7.20 (6H, m, Ph and (H4 or H5)), 6.93–6.84 (2H, m, H3 and (H4 or H5)), 5.05 (3H, m, CH2Ph and OH), 4.13 (1H, m, CH), 3.80–3.60 (2H, m, CH2OH). 13C NMR (125 MHz, DMSO-d6) δ (p.p.m.): 171.6, 157.8, 156.4, 141.2, 137.4, 131.9, 131.6, 129.8, 128.8, 128.3, 128.2, 126.7, 119.9, 119.1, 116.6, 65.9, 61.5, 55.0. IR (cm-1, KBr): 3312 ν(O—H), 1681 ν(COCH and COO). MS/ESI: [M—H]: 356.3.

Refinement top

The C-bound H atoms were geometrically placed (C–H = 0.95–1.00 Å) and refined as riding with Uiso(H) = 1.2–1.5Ueq(C). The O– and N-bound H atoms were located from a difference map and refined with the distance restraints O–H = 0.84 ± 0.01 and N–H = 0.88±0.01 Å, and with Uiso(H) = zUeq(carrier atom); z = 1.5 for O and z = 1.2 for N. In the absence of significant anomalous scattering effects, 1896 Friedel pairs were averaged in the final refinement. However, the absolute configuration was assigned on the basis of the chirality of the L-serine starting material.

Computing details top

Data collection: COLLECT (Hooft, 1998); cell refinement: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); data reduction: DENZO (Otwinowski & Minor, 1997) and COLLECT (Hooft, 1998); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997) and DIAMOND (Brandenburg, 2006); software used to prepare material for publication: publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I) showing displacement ellipsoids at the 50% probability level.
[Figure 2] Fig. 2. A view of the supramolecular array in the ac plane in (I) with the O—H···O and N—H···O hydrogen bonding shown as orange and blue dashed lines, respectively. Hydrogen atoms not participating in the hydrogen bonding scheme are omitted for reasons of clariy.
[Figure 3] Fig. 3. A view in projection down the c axis of the stacking of 2-D supramolecular arrays alng the b axis in (I), and with the O—H···O and N—H···O hydrogen bonding shown as orange and blue dashed lines, respectively.
Benzyl N-(2-hydroxy-1-{N'-[(1E)-2- hydroxybenzylidene]hydrazinecarbonyl}ethyl)carbamate top
Crystal data top
C18H19N3O5F(000) = 376
Mr = 357.36Dx = 1.358 Mg m−3
Monoclinic, P21Mo Kα radiation, λ = 0.71073 Å
Hall symbol: P 2ybCell parameters from 11033 reflections
a = 5.0338 (5) Åθ = 2.9–27.5°
b = 31.357 (3) ŵ = 0.10 mm−1
c = 5.5882 (6) ÅT = 120 K
β = 97.890 (3)°Lath, colourless
V = 873.72 (16) Å30.25 × 0.05 × 0.02 mm
Z = 2
Data collection top
Bruker–Nonius Roper CCD camera on κ-goniostat
diffractometer		2034 independent reflections
Radiation source: Bruker-Nonius FR591 rotating anode1485 reflections with I > 2σ(I)
graphiteRint = 0.066
Detector resolution: 9.091 pixels mm-1θmax = 27.5°, θmin = 3.7°
φ & ω scansh = −6→6
Absorption correction: multi-scan
(SADABS; Sheldrick, 2007)		k = −40→40
Tmin = 0.654, Tmax = 0.746l = −7→7
8786 measured reflections
Refinement top
Refinement on F2Secondary atom site location: difference Fourier map
Least-squares matrix: fullHydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.053H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.098 w = 1/[σ2(Fo2) + (0.0303P)2 + 0.1614P]
where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max < 0.001
2034 reflectionsΔρmax = 0.17 e Å−3
247 parametersΔρmin = −0.20 e Å−3
1 restraintAbsolute structure: nd
Primary atom site location: structure-invariant direct methods
Crystal data top
C18H19N3O5V = 873.72 (16) Å3
Mr = 357.36Z = 2
Monoclinic, P21Mo Kα radiation
a = 5.0338 (5) ŵ = 0.10 mm−1
b = 31.357 (3) ÅT = 120 K
c = 5.5882 (6) Å0.25 × 0.05 × 0.02 mm
β = 97.890 (3)°
Data collection top
Bruker–Nonius Roper CCD camera on κ-goniostat
diffractometer		2034 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2007)		1485 reflections with I > 2σ(I)
Tmin = 0.654, Tmax = 0.746Rint = 0.066
8786 measured reflectionsθmax = 27.5°
Refinement top
R[F2 > 2σ(F2)] = 0.053H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.098Δρmax = 0.17 e Å−3
S = 1.06Δρmin = −0.20 e Å−3
2034 reflectionsAbsolute structure: nd
247 parametersFlack parameter: ?
1 restraintRogers parameter: ?
Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top
xyzUiso*/Ueq
O10.7558 (5)0.24963 (8)0.4299 (5)0.0409 (7)
H1O0.629 (9)0.2299 (15)0.440 (9)0.061*
O20.2652 (5)0.16299 (9)0.6800 (5)0.0427 (7)
O3−0.2389 (5)0.15356 (10)0.8847 (5)0.0443 (7)
H3O−0.401 (10)0.1591 (16)0.838 (8)0.066*
O4−0.5493 (5)0.07490 (8)0.2844 (5)0.0404 (7)
O5−0.2450 (4)0.03271 (7)0.1329 (4)0.0303 (6)
N10.3164 (6)0.20615 (9)0.2693 (6)0.0343 (7)
N20.1183 (6)0.17580 (9)0.2843 (6)0.0331 (7)
H2N−0.011 (8)0.1717 (13)0.159 (7)0.040*
N3−0.1010 (6)0.08812 (9)0.3608 (5)0.0274 (7)
H3N0.069 (7)0.0788 (11)0.327 (6)0.033*
C10.4747 (7)0.26400 (11)0.0505 (7)0.0353 (9)
C20.6973 (7)0.27309 (12)0.2247 (8)0.0366 (9)
C30.8652 (8)0.30728 (12)0.1904 (8)0.0412 (9)
H31.01350.31360.30930.049*
C40.8165 (9)0.33195 (13)−0.0161 (8)0.0472 (11)
H40.93250.3551−0.03860.057*
C50.5994 (9)0.32322 (14)−0.1910 (8)0.0506 (11)
H50.56630.3403−0.33220.061*
C60.4311 (8)0.28924 (13)−0.1577 (8)0.0439 (10)
H60.28410.2830−0.27830.053*
C70.2850 (7)0.22982 (12)0.0788 (8)0.0366 (9)
H70.13760.2250−0.04370.044*
C80.1053 (6)0.15684 (11)0.4959 (6)0.0304 (8)
C9−0.1351 (7)0.12663 (11)0.4999 (6)0.0287 (8)
H9−0.29950.14170.42150.034*
C10−0.1744 (7)0.11639 (12)0.7568 (7)0.0367 (9)
H10A−0.32070.09530.75550.044*
H10B−0.00820.10350.84160.044*
C11−0.3170 (7)0.06639 (11)0.2608 (6)0.0292 (8)
C12−0.4669 (8)0.00648 (12)0.0233 (8)0.0430 (10)
H12A−0.60190.0244−0.07570.052*
H12B−0.5545−0.00760.15030.052*
C13−0.3575 (7)−0.02651 (11)−0.1330 (7)0.0334 (9)
C14−0.1860 (8)−0.01563 (12)−0.2975 (7)0.0384 (9)
H14−0.12890.0131−0.30750.046*
C15−0.0973 (9)−0.04597 (13)−0.4467 (7)0.0451 (10)
H150.0198−0.0380−0.55870.054*
C16−0.1781 (8)−0.08796 (12)−0.4336 (7)0.0435 (10)
H16−0.1178−0.1089−0.53680.052*
C17−0.3479 (8)−0.09931 (13)−0.2687 (7)0.0445 (10)
H17−0.4039−0.1281−0.25880.053*
C18−0.4360 (8)−0.06899 (12)−0.1191 (7)0.0414 (10)
H18−0.5510−0.0771−0.00570.050*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0346 (15)0.0338 (15)0.0538 (17)−0.0029 (12)0.0040 (13)0.0000 (14)
O20.0275 (13)0.0537 (18)0.0434 (15)0.0004 (12)−0.0074 (12)−0.0141 (13)
O30.0277 (13)0.0647 (19)0.0378 (15)0.0139 (14)−0.0050 (11)−0.0248 (14)
O40.0199 (12)0.0454 (16)0.0569 (17)−0.0006 (11)0.0091 (12)−0.0179 (14)
O50.0221 (12)0.0292 (14)0.0398 (14)−0.0031 (10)0.0048 (11)−0.0104 (11)
N10.0247 (15)0.0287 (16)0.049 (2)−0.0013 (13)0.0051 (14)−0.0106 (16)
N20.0261 (16)0.0280 (16)0.044 (2)−0.0023 (13)0.0009 (14)−0.0070 (14)
N30.0178 (14)0.0290 (16)0.0353 (16)0.0022 (12)0.0032 (13)−0.0097 (13)
C10.035 (2)0.030 (2)0.044 (2)0.0020 (16)0.0139 (18)−0.0081 (17)
C20.033 (2)0.0279 (19)0.051 (2)0.0053 (16)0.0136 (18)−0.0052 (19)
C30.034 (2)0.030 (2)0.060 (3)−0.0013 (18)0.0095 (19)−0.005 (2)
C40.044 (2)0.033 (2)0.069 (3)0.0024 (18)0.023 (2)−0.005 (2)
C50.056 (3)0.042 (2)0.057 (3)0.007 (2)0.021 (2)0.001 (2)
C60.047 (2)0.042 (2)0.045 (2)0.0035 (19)0.014 (2)−0.0073 (19)
C70.032 (2)0.030 (2)0.049 (2)0.0038 (15)0.0080 (18)−0.0136 (19)
C80.0210 (17)0.0295 (19)0.039 (2)0.0042 (15)−0.0030 (15)−0.0110 (17)
C90.0230 (17)0.0299 (19)0.0321 (19)0.0057 (15)−0.0003 (15)−0.0035 (15)
C100.0291 (19)0.046 (2)0.034 (2)0.0114 (17)0.0007 (16)−0.0069 (18)
C110.0248 (19)0.0317 (19)0.0318 (19)−0.0024 (15)0.0066 (15)−0.0072 (16)
C120.028 (2)0.040 (2)0.061 (3)−0.0096 (17)0.006 (2)−0.022 (2)
C130.0280 (19)0.029 (2)0.042 (2)−0.0010 (15)0.0006 (17)−0.0080 (17)
C140.042 (2)0.030 (2)0.042 (2)−0.0026 (17)0.0029 (18)−0.0054 (17)
C150.059 (3)0.037 (2)0.041 (2)−0.003 (2)0.013 (2)−0.0047 (19)
C160.057 (3)0.031 (2)0.043 (2)0.0049 (18)0.006 (2)−0.0081 (19)
C170.052 (2)0.029 (2)0.053 (3)−0.0063 (19)0.010 (2)−0.0085 (19)
C180.042 (2)0.039 (2)0.045 (2)−0.0071 (18)0.0127 (19)−0.0061 (19)
Geometric parameters (Å, °) top
O1—C21.360 (5)C5—C61.389 (6)
O1—H1O0.89 (5)C5—H50.9500
O2—C81.231 (4)C6—H60.9500
O3—C101.428 (4)C7—H70.9500
O3—H3O0.84 (5)C8—C91.540 (5)
O4—C111.224 (4)C9—C101.510 (5)
O5—C111.352 (4)C9—H91.0000
O5—C121.453 (4)C10—H10A0.9900
N1—C71.290 (5)C10—H10B0.9900
N1—N21.389 (4)C12—C131.506 (5)
N2—C81.333 (5)C12—H12A0.9900
N2—H2N0.90 (4)C12—H12B0.9900
N3—C111.339 (4)C13—C141.387 (6)
N3—C91.459 (4)C13—C181.395 (5)
N3—H3N0.95 (4)C14—C151.379 (5)
C1—C61.400 (5)C14—H140.9500
C1—C21.409 (5)C15—C161.383 (6)
C1—C71.458 (5)C15—H150.9500
C2—C31.394 (5)C16—C171.387 (6)
C3—C41.383 (6)C16—H160.9500
C3—H30.9500C17—C181.379 (5)
C4—C51.390 (6)C17—H170.9500
C4—H40.9500C18—H180.9500
C2—O1—H1O111 (3)N3—C9—H9108.0
C10—O3—H3O107 (3)C10—C9—H9108.0
C11—O5—C12114.7 (2)C8—C9—H9108.0
C7—N1—N2115.9 (3)O3—C10—C9111.8 (3)
C8—N2—N1118.8 (3)O3—C10—H10A109.3
C8—N2—H2N121 (3)C9—C10—H10A109.3
N1—N2—H2N120 (3)O3—C10—H10B109.3
C11—N3—C9119.7 (3)C9—C10—H10B109.3
C11—N3—H3N118 (2)H10A—C10—H10B107.9
C9—N3—H3N122 (2)O4—C11—N3125.3 (3)
C6—C1—C2118.6 (3)O4—C11—O5123.8 (3)
C6—C1—C7118.4 (4)N3—C11—O5110.9 (3)
C2—C1—C7123.0 (4)O5—C12—C13108.2 (3)
O1—C2—C3117.8 (4)O5—C12—H12A110.1
O1—C2—C1122.2 (3)C13—C12—H12A110.1
C3—C2—C1120.0 (4)O5—C12—H12B110.1
C4—C3—C2120.2 (4)C13—C12—H12B110.1
C4—C3—H3119.9H12A—C12—H12B108.4
C2—C3—H3119.9C14—C13—C18118.6 (3)
C3—C4—C5120.6 (4)C14—C13—C12121.7 (3)
C3—C4—H4119.7C18—C13—C12119.7 (4)
C5—C4—H4119.7C15—C14—C13120.9 (4)
C4—C5—C6119.5 (4)C15—C14—H14119.5
C4—C5—H5120.3C13—C14—H14119.5
C6—C5—H5120.3C14—C15—C16120.2 (4)
C5—C6—C1121.1 (4)C14—C15—H15119.9
C5—C6—H6119.5C16—C15—H15119.9
C1—C6—H6119.5C15—C16—C17119.5 (4)
N1—C7—C1120.3 (3)C15—C16—H16120.3
N1—C7—H7119.8C17—C16—H16120.3
C1—C7—H7119.8C18—C17—C16120.3 (4)
O2—C8—N2124.4 (3)C18—C17—H17119.8
O2—C8—C9120.6 (3)C16—C17—H17119.8
N2—C8—C9114.9 (3)C17—C18—C13120.5 (4)
N3—C9—C10111.8 (3)C17—C18—H18119.7
N3—C9—C8110.6 (3)C13—C18—H18119.7
C10—C9—C8110.5 (3)
C7—N1—N2—C8−165.5 (3)N2—C8—C9—N371.1 (4)
C6—C1—C2—O1−178.9 (3)O2—C8—C9—C1013.6 (4)
C7—C1—C2—O12.0 (5)N2—C8—C9—C10−164.7 (3)
C6—C1—C2—C31.5 (5)N3—C9—C10—O3−173.2 (3)
C7—C1—C2—C3−177.6 (3)C8—C9—C10—O363.2 (3)
O1—C2—C3—C4179.4 (3)C9—N3—C11—O4−3.6 (5)
C1—C2—C3—C4−1.0 (5)C9—N3—C11—O5177.9 (3)
C2—C3—C4—C50.4 (6)C12—O5—C11—O4−0.2 (5)
C3—C4—C5—C6−0.3 (6)C12—O5—C11—N3178.3 (3)
C4—C5—C6—C10.8 (6)C11—O5—C12—C13174.0 (3)
C2—C1—C6—C5−1.4 (5)O5—C12—C13—C14−48.4 (5)
C7—C1—C6—C5177.7 (3)O5—C12—C13—C18133.7 (4)
N2—N1—C7—C1177.1 (3)C18—C13—C14—C150.9 (6)
C6—C1—C7—N1−179.2 (3)C12—C13—C14—C15−177.1 (4)
C2—C1—C7—N1−0.2 (5)C13—C14—C15—C16−0.2 (6)
N1—N2—C8—O2−3.2 (5)C14—C15—C16—C17−0.3 (6)
N1—N2—C8—C9174.9 (3)C15—C16—C17—C180.1 (7)
C11—N3—C9—C1082.9 (4)C16—C17—C18—C130.6 (6)
C11—N3—C9—C8−153.6 (3)C14—C13—C18—C17−1.0 (6)
O2—C8—C9—N3−110.7 (4)C12—C13—C18—C17177.0 (4)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O1—H1o···N10.90 (5)1.88 (5)2.648 (4)143 (4)
O3—H3o···O2i0.84 (5)1.79 (5)2.616 (4)167 (5)
N2—H2n···O3ii0.90 (4)1.87 (4)2.758 (4)168 (4)
N3—H3n···O4iii0.95 (4)1.97 (4)2.897 (4)165 (3)
Symmetry codes: (i) x−1, y, z; (ii) x, y, z−1; (iii) x+1, y, z.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O1—H1o···N10.90 (5)1.88 (5)2.648 (4)143 (4)
O3—H3o···O2i0.84 (5)1.79 (5)2.616 (4)167 (5)
N2—H2n···O3ii0.90 (4)1.87 (4)2.758 (4)168 (4)
N3—H3n···O4iii0.95 (4)1.97 (4)2.897 (4)165 (3)
Symmetry codes: (i) x−1, y, z; (ii) x, y, z−1; (iii) x+1, y, z.
Acknowledgements top

The use of the EPSRC X-ray crystallographic service at the University of Southampton, England, and the valuable assistance of the staff there is gratefully acknowledged. JLW acknowledges support from CAPES (Brazil).

references
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