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Acta Cryst. (2011). E67, o1888-o1889    [ doi:10.1107/S1600536811025293 ]

tert-Butyl N-((1S)-2-hydroxy-1-{N'-[(E)-2-hydroxy-4-methoxybenzylidene]hydrazinecarbonyl}ethyl)carbamate

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

Abstract top

The molecule of the title compound, C16H23N3O6, is twisted about the chiral C atom with the dihedral angle formed between the amide residues being 76.9 (3)°. Overall, the molecule is curved with the terminal organic groups lying to the same side. The conformation about the imine bond [1.291 (5) Å] is E and an intramolecular O-H...N hydrogen bond generates an S(6) ring. In the crystal, O-H...O and N-H...O hydrogen bonds involving the hydroxy, amine and carbonyl groups lead to the formation of supramolecular layers, which stack along the c-axis direction.

Comment top

The analysis of the title compound, (I), was conducted in the context of developing N-acylhydrazone derivatives from L-serine for use in 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; Tiekink et al., 2011) owing to the known anti-tumour activity of L-serine derivatives (Jiao et al., 2009; Yakura et al., 2007).

The absolute structure of (I) could not be determined experimentally but, the assignment of the S-configuration at the C10 atom is based on a starting reagent, L-serine. The structure of (I), Fig. 1, is isomorphous with the analogue not featuring the hydroxyl group in the ring (Pinheiro et al. 2011b). The molecule adopts a curved conformation with both the benzene ring and tert-butyl group lying to the same side of the molecule. Nevertheless, there is a twist in the molecule, at the chiral centre, as seen in the dihedral angle formed between the two amide residues, i.e. N2,C9,O3 and N3,C12,O5, of 76.9 (3) °. The presence of an intramolecular O—H···N hydrogen bond, Table 1, ensures that the hydroxybenzene group is co-planar with the adjacent hydrazine residue with the dihedral angle between the (O3,N1,N2,C8,C9) and (C1–C6) planes being 9.05 (14) °. The conformation about the N1═C8 imine bond [1.291 (5) Å] is E.

As with related structures in this series, hydrogen bonds dominate the crystal packing, Table 1. 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 b 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 ab plane, Fig. 2. The layers stack along the c 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); Tiekink et al. (2011).

Experimental top

To a stirred solution of (S)-t-BuOCONHCH(CH2OH)CONHNH2 (Howie et al., 2011) (1.0 mmol) in ethanol (10 ml) at room temperature was added 2-hydroxy-4-methoxybenzaldehyde (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. 455 K, yield 84%. The sample for the structure determination was recrystallized from EtOH to afford colourless laths of (I).

1H NMR (500 MHz, DMSO-d6) δ (p.p.m.): 11.60 (1H, s, NHN), 11.46 (1H, s, C1—OH), 8.35 (1H, s, N=CH), 7.39 (1H, d, J = 8.4, H6), 6.84 (1H, d, J = 7.4, NHCH), 6.55–6.40 (2H, m, H3 and H5), 4.98 (1H, m, OH), 4.02 (1H, m, CH), 3.76 (3H, s, CH3O), 3.70–3.50 (2H, m, CH2OH), 1.39 (9H, s, (CH3)3C). 13C NMR(125 MHz, DMSO-d6) δ (p.p.m.): 171.5, 162.5, 158.3, 155.7, 141.8, 128.3, 112.1, 106.9, 101.4, 78.5, 61.6, 56.3, 55.6, 28.6. IR (cm-1, KBr): 3375 (O—H), 1677 (COCH and COO). MS/ESI: [M—H]: 352.4.

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, 1703 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 ab 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 a axis of the stacking of 2-D supramolecular arrays along the c axis in (I), and with the O—H···O and N—H···O hydrogen bonding shown as orange and blue dashed lines, respectively.
tert-Butyl N-((1S)-2-hydroxy-1-{N'-[(1E)-2-hydroxy-4- methoxybenzylidene]hydrazinecarbonyl}ethyl)carbamate top
Crystal data top
C16H23N3O6Z = 1
Mr = 353.37F(000) = 188
Triclinic, P1Dx = 1.385 Mg m−3
Hall symbol: P 1Mo Kα radiation, λ = 0.71073 Å
a = 5.3101 (14) ÅCell parameters from 41272 reflections
b = 5.7301 (13) Åθ = 2.9–27.5°
c = 14.651 (4) ŵ = 0.11 mm−1
α = 80.364 (16)°T = 120 K
β = 84.788 (11)°Lath, colourless
γ = 74.845 (15)°0.62 × 0.18 × 0.03 mm
V = 423.70 (19) Å3
Data collection top
Bruker–Nonius Roper CCD camera on κ-goniostat
diffractometer		1936 independent reflections
Radiation source: Bruker–Nonius FR591 rotating anode1639 reflections with I > 2σ(I)
graphiteRint = 0.092
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 = −7→7
Tmin = 0.415, Tmax = 0.746l = −18→18
7849 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)] = 0.062H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.158 w = 1/[σ2(Fo2) + (0.0932P)2 + 0.0716P]
where P = (Fo2 + 2Fc2)/3
S = 1.06(Δ/σ)max < 0.001
1936 reflectionsΔρmax = 0.26 e Å−3
242 parametersΔρmin = −0.32 e Å−3
7 restraintsAbsolute structure: nd
Primary atom site location: structure-invariant direct methods
Crystal data top
C16H23N3O6γ = 74.845 (15)°
Mr = 353.37V = 423.70 (19) Å3
Triclinic, P1Z = 1
a = 5.3101 (14) ÅMo Kα radiation
b = 5.7301 (13) ŵ = 0.11 mm−1
c = 14.651 (4) ÅT = 120 K
α = 80.364 (16)°0.62 × 0.18 × 0.03 mm
β = 84.788 (11)°
Data collection top
Bruker–Nonius Roper CCD camera on κ-goniostat
diffractometer		1936 independent reflections
Absorption correction: multi-scan
(SADABS; Sheldrick, 2007)		1639 reflections with I > 2σ(I)
Tmin = 0.415, Tmax = 0.746Rint = 0.092
7849 measured reflectionsθmax = 27.5°
Refinement top
R[F2 > 2σ(F2)] = 0.062H atoms treated by a mixture of independent and constrained refinement
wR(F2) = 0.158Δρmax = 0.26 e Å−3
S = 1.06Δρmin = −0.32 e Å−3
1936 reflectionsAbsolute structure: nd
242 parametersFlack parameter: ?
7 restraintsRogers 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
O11.3235 (6)−0.0932 (5)1.0670 (2)0.0337 (7)
H1o1.233 (10)−0.078 (11)1.021 (3)0.051*
O21.5080 (6)0.3094 (6)1.3026 (2)0.0365 (7)
O30.8525 (6)−0.2427 (5)0.8860 (2)0.0359 (7)
O40.3605 (6)−0.3907 (5)0.8847 (2)0.0330 (7)
H4o0.201 (3)−0.351 (11)0.901 (4)0.049*
O50.0570 (6)0.2513 (5)0.7006 (2)0.0318 (7)
O60.3497 (6)0.4260 (5)0.6066 (2)0.0307 (7)
N10.8884 (7)0.1219 (6)0.9773 (2)0.0296 (8)
N20.6946 (7)0.1467 (6)0.9162 (2)0.0289 (7)
H2n0.564 (7)0.277 (6)0.907 (3)0.035*
N30.4886 (7)0.1547 (6)0.7304 (2)0.0290 (8)
H3n0.630 (6)0.207 (9)0.712 (3)0.035*
C11.0379 (8)0.2948 (7)1.0923 (3)0.0277 (8)
C21.2576 (8)0.1000 (7)1.1135 (3)0.0296 (9)
C31.4175 (8)0.0995 (7)1.1835 (3)0.0285 (8)
H31.5648−0.03411.19720.034*
C41.3625 (8)0.2931 (8)1.2332 (3)0.0311 (9)
C51.1485 (10)0.4908 (8)1.2127 (3)0.0360 (10)
H51.11410.62611.24560.043*
C60.9868 (9)0.4896 (8)1.1443 (3)0.0351 (10)
H60.83810.62261.13200.042*
C71.7297 (9)0.1110 (9)1.3266 (3)0.0380 (10)
H7A1.6729−0.04031.34540.057*
H7B1.81470.14401.37790.057*
H7C1.85340.09331.27280.057*
C80.8536 (9)0.2999 (8)1.0244 (3)0.0313 (9)
H80.70590.43531.01460.038*
C90.6886 (8)−0.0437 (7)0.8759 (3)0.0298 (9)
C100.4544 (8)−0.0039 (7)0.8164 (3)0.0283 (9)
H100.29310.07780.85090.034*
C110.4262 (9)−0.2510 (7)0.7997 (3)0.0322 (9)
H11A0.2880−0.22580.75540.039*
H11B0.5923−0.34210.77200.039*
C120.2788 (8)0.2769 (7)0.6807 (3)0.0279 (8)
C130.1569 (8)0.5755 (7)0.5405 (3)0.0296 (9)
C14−0.0560 (9)0.7519 (8)0.5888 (3)0.0353 (10)
H14A−0.16940.66160.62800.053*
H14B−0.15960.87360.54240.053*
H14C0.02360.83470.62740.053*
C150.3213 (9)0.7096 (8)0.4718 (3)0.0347 (10)
H15A0.40010.80720.50420.052*
H15B0.21060.81760.42390.052*
H15C0.45950.59080.44280.052*
C160.0458 (9)0.4084 (8)0.4931 (3)0.0337 (9)
H16A0.18960.28430.46940.051*
H16B−0.05830.50580.44160.051*
H16C−0.06510.32820.53800.051*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
O10.0317 (16)0.0303 (15)0.0357 (16)0.0037 (12)−0.0057 (12)−0.0114 (12)
O20.0309 (17)0.0413 (18)0.0365 (17)−0.0023 (13)−0.0052 (13)−0.0125 (13)
O30.0266 (16)0.0257 (15)0.0500 (19)0.0022 (12)−0.0051 (13)−0.0032 (13)
O40.0271 (15)0.0236 (14)0.0406 (17)0.0028 (12)−0.0029 (13)0.0025 (12)
O50.0281 (16)0.0255 (15)0.0386 (17)−0.0033 (11)−0.0039 (12)−0.0002 (12)
O60.0267 (15)0.0273 (14)0.0327 (15)0.0000 (11)−0.0064 (12)0.0023 (11)
N10.0277 (18)0.0285 (18)0.0288 (17)−0.0005 (14)−0.0054 (13)−0.0018 (14)
N20.0253 (18)0.0279 (18)0.0296 (17)0.0007 (13)−0.0051 (14)−0.0027 (14)
N30.0272 (18)0.0242 (17)0.0315 (18)−0.0005 (14)−0.0037 (14)−0.0007 (14)
C10.028 (2)0.025 (2)0.028 (2)−0.0023 (16)−0.0034 (15)−0.0022 (15)
C20.030 (2)0.025 (2)0.031 (2)−0.0014 (17)0.0016 (17)−0.0060 (16)
C30.026 (2)0.0257 (19)0.031 (2)0.0015 (15)−0.0026 (16)−0.0059 (15)
C40.031 (2)0.032 (2)0.028 (2)−0.0038 (17)0.0016 (17)−0.0050 (17)
C50.045 (3)0.029 (2)0.033 (2)−0.0061 (19)−0.0011 (19)−0.0093 (17)
C60.035 (2)0.025 (2)0.038 (2)0.0014 (17)−0.0014 (18)−0.0016 (17)
C70.039 (3)0.036 (2)0.035 (2)−0.002 (2)−0.0066 (19)−0.0059 (19)
C80.031 (2)0.027 (2)0.033 (2)−0.0033 (17)−0.0044 (17)−0.0004 (16)
C90.028 (2)0.0241 (19)0.031 (2)0.0029 (16)−0.0033 (16)−0.0017 (15)
C100.027 (2)0.0256 (19)0.028 (2)0.0012 (16)−0.0030 (16)−0.0021 (15)
C110.034 (2)0.027 (2)0.032 (2)0.0005 (17)−0.0032 (18)−0.0045 (17)
C120.030 (2)0.0211 (18)0.029 (2)0.0001 (15)−0.0033 (16)−0.0017 (15)
C130.031 (2)0.0217 (19)0.031 (2)0.0020 (16)−0.0042 (16)−0.0005 (15)
C140.039 (2)0.026 (2)0.035 (2)0.0025 (18)−0.0022 (18)−0.0044 (17)
C150.036 (2)0.028 (2)0.035 (2)0.0008 (18)−0.0037 (18)−0.0020 (17)
C160.034 (2)0.028 (2)0.037 (2)−0.0026 (17)−0.0051 (18)−0.0062 (17)
Geometric parameters (Å, °) top
O1—C21.348 (5)C5—C61.379 (7)
O1—H1o0.842 (11)C5—H50.9500
O2—C41.362 (5)C6—H60.9500
O2—C71.429 (5)C7—H7A0.9800
O3—C91.236 (5)C7—H7B0.9800
O4—C111.432 (5)C7—H7C0.9800
O4—H4o0.841 (11)C8—H80.9500
O5—C121.228 (5)C9—C101.530 (6)
O6—C121.353 (5)C10—C111.523 (6)
O6—C131.472 (5)C10—H101.0000
N1—C81.291 (5)C11—H11A0.9900
N1—N21.388 (5)C11—H11B0.9900
N2—C91.333 (5)C13—C141.516 (6)
N2—H2n0.880 (10)C13—C151.516 (6)
N3—C121.353 (5)C13—C161.529 (6)
N3—C101.452 (5)C14—H14A0.9800
N3—H3n0.882 (11)C14—H14B0.9800
C1—C21.404 (5)C14—H14C0.9800
C1—C61.410 (6)C15—H15A0.9800
C1—C81.449 (6)C15—H15B0.9800
C2—C31.389 (6)C15—H15C0.9800
C3—C41.381 (6)C16—H16A0.9800
C3—H30.9500C16—H16B0.9800
C4—C51.393 (6)C16—H16C0.9800
C2—O1—H1o114 (4)N2—C9—C10115.1 (3)
C4—O2—C7117.7 (3)N3—C10—C11112.1 (3)
C11—O4—H4o114 (4)N3—C10—C9109.5 (3)
C12—O6—C13121.0 (3)C11—C10—C9109.2 (3)
C8—N1—N2114.7 (3)N3—C10—H10108.6
C9—N2—N1119.3 (3)C11—C10—H10108.6
C9—N2—H2n117 (3)C9—C10—H10108.6
N1—N2—H2n124 (3)O4—C11—C10110.7 (3)
C12—N3—C10119.8 (3)O4—C11—H11A109.5
C12—N3—H3n113 (3)C10—C11—H11A109.5
C10—N3—H3n126 (3)O4—C11—H11B109.5
C2—C1—C6117.6 (4)C10—C11—H11B109.5
C2—C1—C8123.9 (4)H11A—C11—H11B108.1
C6—C1—C8118.4 (4)O5—C12—N3123.8 (4)
O1—C2—C3117.1 (3)O5—C12—O6125.6 (4)
O1—C2—C1121.9 (4)N3—C12—O6110.5 (4)
C3—C2—C1121.0 (4)O6—C13—C14110.6 (3)
C4—C3—C2120.1 (4)O6—C13—C15102.4 (3)
C4—C3—H3120.0C14—C13—C15111.4 (3)
C2—C3—H3120.0O6—C13—C16109.5 (3)
O2—C4—C3124.3 (4)C14—C13—C16111.9 (4)
O2—C4—C5115.4 (4)C15—C13—C16110.7 (4)
C3—C4—C5120.2 (4)C13—C14—H14A109.5
C6—C5—C4119.8 (4)C13—C14—H14B109.5
C6—C5—H5120.1H14A—C14—H14B109.5
C4—C5—H5120.1C13—C14—H14C109.5
C5—C6—C1121.3 (4)H14A—C14—H14C109.5
C5—C6—H6119.3H14B—C14—H14C109.5
C1—C6—H6119.3C13—C15—H15A109.5
O2—C7—H7A109.5C13—C15—H15B109.5
O2—C7—H7B109.5H15A—C15—H15B109.5
H7A—C7—H7B109.5C13—C15—H15C109.5
O2—C7—H7C109.5H15A—C15—H15C109.5
H7A—C7—H7C109.5H15B—C15—H15C109.5
H7B—C7—H7C109.5C13—C16—H16A109.5
N1—C8—C1120.5 (4)C13—C16—H16B109.5
N1—C8—H8119.7H16A—C16—H16B109.5
C1—C8—H8119.7C13—C16—H16C109.5
O3—C9—N2124.3 (4)H16A—C16—H16C109.5
O3—C9—C10120.6 (4)H16B—C16—H16C109.5
C8—N1—N2—C9−168.9 (4)C6—C1—C8—N1−177.9 (4)
C6—C1—C2—O1−179.4 (4)N1—N2—C9—O3−3.1 (6)
C8—C1—C2—O14.4 (6)N1—N2—C9—C10175.1 (3)
C6—C1—C2—C30.3 (6)C12—N3—C10—C1179.4 (4)
C8—C1—C2—C3−175.8 (4)C12—N3—C10—C9−159.2 (3)
O1—C2—C3—C4179.4 (4)O3—C9—C10—N3−107.6 (4)
C1—C2—C3—C4−0.4 (6)N2—C9—C10—N374.1 (4)
C7—O2—C4—C3−1.1 (6)O3—C9—C10—C1115.5 (5)
C7—O2—C4—C5179.9 (4)N2—C9—C10—C11−162.8 (4)
C2—C3—C4—O2−179.7 (4)N3—C10—C11—O4−172.8 (3)
C2—C3—C4—C5−0.8 (6)C9—C10—C11—O465.6 (4)
O2—C4—C5—C6−179.0 (4)C10—N3—C12—O5−4.8 (6)
C3—C4—C5—C61.9 (7)C10—N3—C12—O6176.0 (3)
C4—C5—C6—C1−2.0 (7)C13—O6—C12—O5−0.4 (6)
C2—C1—C6—C50.9 (7)C13—O6—C12—N3178.8 (3)
C8—C1—C6—C5177.2 (4)C12—O6—C13—C1460.8 (5)
N2—N1—C8—C1178.5 (4)C12—O6—C13—C15179.6 (3)
C2—C1—C8—N1−1.8 (7)C12—O6—C13—C16−62.9 (4)
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O1—H1o···N10.84 (5)1.99 (6)2.666 (5)137 (5)
O4—H4o···O3i0.84 (3)1.81 (3)2.607 (5)157 (6)
N2—H2n···O4ii0.88 (4)1.92 (3)2.769 (5)163 (4)
N3—H3n···O5iii0.88 (4)2.34 (4)3.188 (5)162 (4)
Symmetry codes: (i) x−1, y, z; (ii) x, y+1, z; (iii) x+1, y, z.
Table 1
Hydrogen-bond geometry (Å, °) top
D—H···AD—HH···AD···AD—H···A
O1—H1o···N10.84 (5)1.99 (6)2.666 (5)137 (5)
O4—H4o···O3i0.84 (3)1.81 (3)2.607 (5)157 (6)
N2—H2n···O4ii0.88 (4)1.92 (3)2.769 (5)163 (4)
N3—H3n···O5iii0.88 (4)2.34 (4)3.188 (5)162 (4)
Symmetry codes: (i) x−1, y, z; (ii) x, y+1, z; (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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