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The title compound, C
23H
16N
4O
4, can be considered as consisting of two connected fragments: a nitrophenylhydrazone moiety, which assumes an
E configuration, and an isoxazole moiety. In this latter fragment, the weak π-electron delocalization shortens the carbonyl–isoxazole O
O distance [2.643 (2) Å] to less than the van der Waals radii sum.
Supporting information
CCDC reference: 142783
3-Phenyl-p-nitrophenylhydrazone-5-phenacylisoxazole (1 mmol) was dissolved in hot chloroform (40 ml). Br2 (2 mmol) was added with continuous stirring and the mixture refluxed for 4 h. During the reaction a powder began to precipitate. The solid was removed by filtration and the organic phase was separated and evaporated to dryness. The residue, (I), was crystallized from acetone at room temperature (m.p. 422–424 K). Single crystals of (I) suitable for X-ray diffraction analysis were grown from a CH2Cl2/CH3OH mixture (~1:2 v/v).
Data collection: P3/V (Siemens,1989); cell refinement: P3/V; data reduction: SHELXTL-Plus (Sheldrick, 1990); program(s) used to solve structure: ??; program(s) used to refine structure: SHELXL97 (Sheldrick, 1997); molecular graphics: XPW (Siemens, 1996); software used to prepare material for publication: locally modified PARST97 (Nardelli, 1995) and SHELXL97.
(
E)-5-[(4-Nitrophenylhydrazono)phenylacetyl]-3-phenylisoxazole
top
Crystal data top
C23H16N4O4 | F(000) = 856 |
Mr = 412.40 | Dx = 1.393 Mg m−3 |
Monoclinic, P21/n | Mo Kα radiation, λ = 0.71073 Å |
a = 5.787 (1) Å | Cell parameters from 41 reflections |
b = 29.089 (3) Å | θ = 12–28° |
c = 11.881 (1) Å | µ = 0.10 mm−1 |
β = 100.49 (1)° | T = 293 K |
V = 1966.6 (4) Å3 | Prismatic, colourless |
Z = 4 | 0.25 × 0.18 × 0.12 mm |
Data collection top
Siemens R3m/V diffractometer | Rint = 0.013 |
Radiation source: fine-focus sealed tube | θmax = 24.5°, θmin = 1.9° |
Graphite monochromator | h = −1→6 |
ω/2θ scans | k = −7→34 |
3739 measured reflections | l = −13→13 |
3301 independent reflections | 3 standard reflections every 197 reflections |
1899 reflections with I > 2σ(I) | intensity decay: 1.3% |
Refinement top
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)] = 0.034 | H-atom parameters constrained |
wR(F2) = 0.079 | Calculated w = 1/[σ2(Fo2) + (0.1383P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.84 | (Δ/σ)max = 0.001 |
3301 reflections | Δρmax = 0.23 e Å−3 |
282 parameters | Δρmin = −0.19 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 1997), Fc*=kFc[1+0.001Fc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.085 (7) |
Crystal data top
C23H16N4O4 | V = 1966.6 (4) Å3 |
Mr = 412.40 | Z = 4 |
Monoclinic, P21/n | Mo Kα radiation |
a = 5.787 (1) Å | µ = 0.10 mm−1 |
b = 29.089 (3) Å | T = 293 K |
c = 11.881 (1) Å | 0.25 × 0.18 × 0.12 mm |
β = 100.49 (1)° | |
Data collection top
Siemens R3m/V diffractometer | Rint = 0.013 |
3739 measured reflections | 3 standard reflections every 197 reflections |
3301 independent reflections | intensity decay: 1.3% |
1899 reflections with I > 2σ(I) | |
Refinement top
R[F2 > 2σ(F2)] = 0.034 | 0 restraints |
wR(F2) = 0.079 | H-atom parameters constrained |
S = 0.84 | Δρmax = 0.23 e Å−3 |
3301 reflections | Δρmin = −0.19 e Å−3 |
282 parameters | |
Special details top
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. |
Refinement. Refinement on F2 for ALL reflections except for 1 with very negative F2 or flagged by the user for potential systematic errors. Weighted R-factors wR and all goodnesses of fit S are based on F2, conventional R-factors R are based on F, with F set to zero for negative F2. Reflection intensities were evaluated by profile fitting of a 96-steps peak scan among 2θ shells (Diamond, 1969) and then corrected for Lorentz polarization effects. Standard uncertainties σ(I) were estimated from counting statistics. All non-H atoms were refined anisotropically. H atoms were located on idealized positions and allowed to ride on their parent C atoms, with a common isotropic displacement parameter (Uiso = 0.08 Å2). |
Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å2) top | x | y | z | Uiso*/Ueq | |
O1 | 0.8535 (2) | 0.07201 (5) | 0.88060 (11) | 0.0600 (4) | |
N1 | 0.8998 (3) | 0.05888 (6) | 0.99588 (14) | 0.0607 (5) | |
C3 | 0.6952 (3) | 0.05817 (6) | 1.02930 (15) | 0.0455 (5) | |
C2 | 0.5123 (3) | 0.07198 (6) | 0.93893 (15) | 0.0473 (5) | |
H2 | 0.3532 | 0.0749 | 0.9411 | 0.069* | |
C1 | 0.6201 (3) | 0.08003 (6) | 0.84946 (16) | 0.0457 (5) | |
C4 | 0.5523 (3) | 0.09232 (6) | 0.72602 (16) | 0.0490 (5) | |
O2 | 0.6775 (2) | 0.07956 (5) | 0.65995 (11) | 0.0693 (4) | |
C5 | 0.3423 (3) | 0.12078 (6) | 0.68579 (15) | 0.0436 (5) | |
C6 | 0.2777 (3) | 0.13099 (6) | 0.56121 (14) | 0.0448 (5) | |
C7 | 0.0650 (3) | 0.11653 (7) | 0.49840 (17) | 0.0552 (5) | |
H7 | −0.0407 | 0.1006 | 0.5342 | 0.069* | |
C8 | 0.0098 (4) | 0.12576 (8) | 0.38234 (18) | 0.0706 (6) | |
H8 | −0.1334 | 0.1162 | 0.3401 | 0.069* | |
C9 | 0.1674 (5) | 0.14915 (8) | 0.32957 (18) | 0.0773 (7) | |
H9 | 0.1304 | 0.1551 | 0.2514 | 0.069* | |
C10 | 0.3775 (4) | 0.16377 (8) | 0.39078 (18) | 0.0713 (6) | |
H10 | 0.4820 | 0.1800 | 0.3547 | 0.069* | |
C11 | 0.4334 (3) | 0.15449 (7) | 0.50557 (17) | 0.0568 (5) | |
H11 | 0.5775 | 0.1640 | 0.5469 | 0.069* | |
N2 | 0.2370 (2) | 0.13680 (5) | 0.76546 (12) | 0.0452 (4) | |
N3 | 0.0546 (2) | 0.16550 (5) | 0.73490 (12) | 0.0481 (4) | |
H3 | 0.0097 | 0.1727 | 0.6641 | 0.069* | |
C12 | 0.6840 (3) | 0.04363 (6) | 1.14708 (15) | 0.0446 (5) | |
C13 | 0.4950 (3) | 0.05505 (7) | 1.19838 (17) | 0.0582 (5) | |
H13 | 0.3707 | 0.0719 | 1.1577 | 0.069* | |
C14 | 0.4895 (3) | 0.04160 (8) | 1.30928 (18) | 0.0701 (6) | |
H14 | 0.3631 | 0.0498 | 1.3434 | 0.069* | |
C15 | 0.6713 (4) | 0.01607 (8) | 1.36954 (18) | 0.0698 (6) | |
H15 | 0.6681 | 0.0071 | 1.4444 | 0.069* | |
C16 | 0.8579 (4) | 0.00378 (7) | 1.31875 (18) | 0.0645 (6) | |
H16 | 0.9796 | −0.0139 | 1.3589 | 0.069* | |
C17 | 0.8645 (3) | 0.01749 (6) | 1.20877 (17) | 0.0568 (5) | |
H17 | 0.9916 | 0.0092 | 1.1752 | 0.069* | |
C18 | −0.0614 (3) | 0.18357 (6) | 0.81716 (14) | 0.0418 (4) | |
C19 | −0.2554 (3) | 0.21144 (6) | 0.78165 (15) | 0.0465 (5) | |
H19 | −0.3013 | 0.2182 | 0.7043 | 0.069* | |
C20 | −0.3811 (3) | 0.22922 (6) | 0.85954 (15) | 0.0495 (5) | |
H20 | −0.5119 | 0.2477 | 0.8356 | 0.069* | |
C21 | −0.3090 (3) | 0.21899 (6) | 0.97339 (16) | 0.0529 (5) | |
N4 | −0.4360 (4) | 0.23844 (7) | 1.05652 (16) | 0.0741 (5) | |
O3 | −0.3765 (4) | 0.22739 (7) | 1.15683 (14) | 0.1352 (8) | |
O4 | −0.5933 (3) | 0.26640 (6) | 1.02438 (13) | 0.0821 (5) | |
C22 | −0.1163 (4) | 0.19186 (8) | 1.00953 (17) | 0.0709 (7) | |
H22 | −0.0705 | 0.1854 | 1.0870 | 0.069* | |
C23 | 0.0090 (4) | 0.17408 (7) | 0.93264 (15) | 0.0619 (6) | |
H23 | 0.1402 | 0.1558 | 0.9575 | 0.069* | |
Atomic displacement parameters (Å2) top | U11 | U22 | U33 | U12 | U13 | U23 |
O1 | 0.0406 (8) | 0.0772 (10) | 0.0642 (9) | 0.0087 (7) | 0.0147 (7) | 0.0088 (7) |
N1 | 0.0446 (9) | 0.0767 (13) | 0.0606 (11) | 0.0077 (9) | 0.0089 (8) | 0.0121 (9) |
C3 | 0.0391 (10) | 0.0430 (11) | 0.0542 (12) | 0.0012 (9) | 0.0079 (9) | −0.0037 (9) |
C2 | 0.0366 (10) | 0.0510 (12) | 0.0547 (12) | 0.0020 (9) | 0.0091 (9) | −0.0011 (10) |
C1 | 0.0371 (10) | 0.0486 (12) | 0.0520 (12) | 0.0039 (9) | 0.0093 (9) | −0.0005 (9) |
C4 | 0.0447 (11) | 0.0508 (12) | 0.0556 (13) | −0.0002 (9) | 0.0195 (10) | −0.0037 (10) |
O2 | 0.0635 (9) | 0.0859 (11) | 0.0654 (10) | 0.0203 (8) | 0.0305 (8) | 0.0047 (8) |
C5 | 0.0418 (11) | 0.0450 (11) | 0.0467 (12) | −0.0040 (9) | 0.0154 (9) | −0.0034 (9) |
C6 | 0.0436 (11) | 0.0487 (12) | 0.0444 (11) | 0.0020 (9) | 0.0137 (9) | −0.0036 (9) |
C7 | 0.0523 (12) | 0.0602 (14) | 0.0542 (13) | 0.0006 (10) | 0.0130 (10) | −0.0053 (10) |
C8 | 0.0658 (14) | 0.0855 (17) | 0.0564 (15) | 0.0151 (13) | 0.0007 (12) | −0.0108 (13) |
C9 | 0.0954 (19) | 0.0930 (19) | 0.0436 (14) | 0.0313 (16) | 0.0130 (14) | 0.0114 (12) |
C10 | 0.0791 (17) | 0.0777 (17) | 0.0637 (15) | 0.0131 (14) | 0.0303 (13) | 0.0214 (12) |
C11 | 0.0551 (12) | 0.0620 (14) | 0.0558 (13) | −0.0015 (11) | 0.0172 (10) | 0.0017 (11) |
N2 | 0.0434 (9) | 0.0446 (9) | 0.0495 (10) | 0.0014 (8) | 0.0135 (7) | −0.0017 (8) |
N3 | 0.0514 (9) | 0.0534 (10) | 0.0421 (9) | 0.0092 (8) | 0.0151 (8) | 0.0016 (7) |
C12 | 0.0383 (10) | 0.0434 (11) | 0.0498 (11) | −0.0003 (9) | 0.0021 (9) | −0.0019 (9) |
C13 | 0.0450 (11) | 0.0701 (15) | 0.0588 (13) | 0.0076 (10) | 0.0075 (10) | 0.0109 (11) |
C14 | 0.0534 (13) | 0.0938 (18) | 0.0658 (15) | 0.0083 (12) | 0.0179 (11) | 0.0132 (13) |
C15 | 0.0632 (14) | 0.0868 (17) | 0.0587 (14) | −0.0053 (13) | 0.0091 (12) | 0.0165 (12) |
C16 | 0.0563 (13) | 0.0659 (15) | 0.0675 (15) | 0.0069 (11) | 0.0018 (11) | 0.0135 (12) |
C17 | 0.0506 (12) | 0.0556 (13) | 0.0635 (14) | 0.0075 (10) | 0.0083 (10) | 0.0000 (11) |
C18 | 0.0474 (11) | 0.0376 (11) | 0.0424 (11) | −0.0004 (9) | 0.0138 (9) | −0.0046 (8) |
C19 | 0.0530 (11) | 0.0506 (12) | 0.0376 (11) | 0.0025 (10) | 0.0129 (9) | 0.0017 (9) |
C20 | 0.0536 (11) | 0.0472 (12) | 0.0488 (12) | 0.0041 (10) | 0.0125 (10) | −0.0046 (9) |
C21 | 0.0684 (13) | 0.0526 (13) | 0.0406 (11) | 0.0079 (11) | 0.0176 (10) | −0.0081 (10) |
N4 | 0.0978 (15) | 0.0801 (14) | 0.0483 (12) | 0.0196 (12) | 0.0234 (11) | −0.0102 (10) |
O3 | 0.189 (2) | 0.174 (2) | 0.0517 (11) | 0.0875 (16) | 0.0472 (12) | 0.0072 (12) |
O4 | 0.0861 (11) | 0.0916 (12) | 0.0725 (11) | 0.0268 (10) | 0.0250 (9) | −0.0153 (9) |
C22 | 0.0965 (17) | 0.0796 (16) | 0.0357 (12) | 0.0288 (14) | 0.0096 (12) | −0.0015 (11) |
C23 | 0.0724 (14) | 0.0708 (15) | 0.0414 (12) | 0.0234 (12) | 0.0070 (10) | −0.0022 (10) |
Geometric parameters (Å, º) top
O1—C1 | 1.354 (2) | N2—N3 | 1.343 (2) |
O1—N1 | 1.400 (2) | N3—C18 | 1.386 (2) |
N1—C3 | 1.316 (2) | C12—C13 | 1.386 (2) |
C3—C2 | 1.421 (2) | C12—C17 | 1.388 (2) |
C3—C12 | 1.475 (2) | C13—C14 | 1.380 (3) |
C2—C1 | 1.347 (2) | C14—C15 | 1.377 (3) |
C1—C4 | 1.491 (2) | C15—C16 | 1.377 (3) |
C4—O2 | 1.219 (2) | C16—C17 | 1.373 (3) |
C4—C5 | 1.476 (2) | C18—C23 | 1.386 (2) |
C5—N2 | 1.302 (2) | C18—C19 | 1.387 (2) |
C5—C6 | 1.489 (2) | C19—C20 | 1.377 (2) |
C6—C7 | 1.383 (2) | C20—C21 | 1.374 (2) |
C6—C11 | 1.390 (2) | C21—C22 | 1.370 (3) |
C7—C8 | 1.384 (2) | C21—N4 | 1.449 (2) |
C8—C9 | 1.377 (3) | N4—O3 | 1.222 (2) |
C9—C10 | 1.366 (3) | N4—O4 | 1.229 (2) |
C10—C11 | 1.370 (3) | C22—C23 | 1.367 (2) |
| | | |
C1—O1—N1 | 108.5 (1) | C5—N2—N3 | 118.3 (2) |
C3—N1—O1 | 106.1 (2) | N2—N3—C18 | 120.2 (2) |
N1—C3—C2 | 110.8 (2) | C13—C12—C17 | 118.51 (18) |
N1—C3—C12 | 119.2 (2) | C13—C12—C3 | 121.55 (16) |
C2—C3—C12 | 129.98 (15) | C17—C12—C3 | 119.93 (17) |
C1—C2—C3 | 104.9 (2) | C14—C13—C12 | 120.60 (18) |
C2—C1—O1 | 109.7 (2) | C15—C14—C13 | 120.1 (2) |
C2—C1—C4 | 137.83 (17) | C16—C15—C14 | 119.9 (2) |
O1—C1—C4 | 112.4 (2) | C17—C16—C15 | 120.09 (19) |
O2—C4—C5 | 120.9 (2) | C16—C17—C12 | 120.85 (19) |
O2—C4—C1 | 118.7 (2) | C23—C18—N3 | 122.0 (2) |
C5—C4—C1 | 120.44 (16) | C23—C18—C19 | 119.57 (17) |
N2—C5—C4 | 115.6 (2) | N3—C18—C19 | 118.5 (2) |
N2—C5—C6 | 125.8 (2) | C20—C19—C18 | 120.80 (17) |
C4—C5—C6 | 118.47 (15) | C21—C20—C19 | 118.53 (18) |
C7—C6—C11 | 118.87 (17) | C22—C21—C20 | 121.15 (18) |
C7—C6—C5 | 120.87 (17) | C22—C21—N4 | 119.8 (2) |
C11—C6—C5 | 120.24 (16) | C20—C21—N4 | 119.1 (2) |
C6—C7—C8 | 119.99 (19) | O3—N4—O4 | 122.6 (2) |
C9—C8—C7 | 119.8 (2) | O3—N4—C21 | 118.3 (2) |
C10—C9—C8 | 120.7 (2) | O4—N4—C21 | 119.1 (2) |
C9—C10—C11 | 119.6 (2) | C23—C22—C21 | 120.60 (19) |
C10—C11—C6 | 120.95 (19) | C22—C23—C18 | 119.34 (19) |
| | | |
C1—O1—N1—C3 | 1.7 (2) | C6—C5—N2—N3 | −0.6 (3) |
O1—N1—C3—C2 | −1.7 (2) | C5—N2—N3—C18 | −179.58 (15) |
O1—N1—C3—C12 | 177.56 (14) | N1—C3—C12—C13 | 160.04 (19) |
N1—C3—C2—C1 | 1.2 (2) | C2—C3—C12—C13 | −20.8 (3) |
C12—C3—C2—C1 | −178.03 (17) | N1—C3—C12—C17 | −20.6 (3) |
C3—C2—C1—O1 | −0.1 (2) | C2—C3—C12—C17 | 158.54 (18) |
C3—C2—C1—C4 | 175.2 (2) | C17—C12—C13—C14 | 1.5 (3) |
N1—O1—C1—C2 | −1.0 (2) | C3—C12—C13—C14 | −179.14 (18) |
N1—O1—C1—C4 | −177.53 (14) | C12—C13—C14—C15 | −0.9 (3) |
C2—C1—C4—O2 | −150.8 (2) | C13—C14—C15—C16 | −0.4 (3) |
O1—C1—C4—O2 | 24.3 (2) | C14—C15—C16—C17 | 0.9 (3) |
C2—C1—C4—C5 | 31.3 (3) | C15—C16—C17—C12 | −0.3 (3) |
O1—C1—C4—C5 | −153.52 (16) | C13—C12—C17—C16 | −0.9 (3) |
O2—C4—C5—N2 | −172.44 (17) | C3—C12—C17—C16 | 179.71 (17) |
C1—C4—C5—N2 | 5.4 (2) | N2—N3—C18—C23 | 2.0 (2) |
O2—C4—C5—C6 | 4.0 (3) | N2—N3—C18—C19 | −177.16 (14) |
C1—C4—C5—C6 | −178.22 (16) | C23—C18—C19—C20 | −1.0 (3) |
N2—C5—C6—C7 | −65.6 (2) | N3—C18—C19—C20 | 178.14 (16) |
C4—C5—C6—C7 | 118.38 (19) | C18—C19—C20—C21 | 0.4 (3) |
N2—C5—C6—C11 | 115.8 (2) | C19—C20—C21—C22 | 0.2 (3) |
C4—C5—C6—C11 | −60.3 (2) | C19—C20—C21—N4 | 178.41 (17) |
C11—C6—C7—C8 | −0.4 (3) | C22—C21—N4—O3 | −5.0 (3) |
C5—C6—C7—C8 | −179.02 (18) | C20—C21—N4—O3 | 176.8 (2) |
C6—C7—C8—C9 | 0.3 (3) | C22—C21—N4—O4 | 172.6 (2) |
C7—C8—C9—C10 | −0.6 (3) | C20—C21—N4—O4 | −5.6 (3) |
C8—C9—C10—C11 | 0.9 (3) | C20—C21—C22—C23 | −0.2 (3) |
C9—C10—C11—C6 | −1.0 (3) | N4—C21—C22—C23 | −178.45 (19) |
C7—C6—C11—C10 | 0.7 (3) | C21—C22—C23—C18 | −0.3 (3) |
C5—C6—C11—C10 | 179.38 (18) | N3—C18—C23—C22 | −178.17 (18) |
C4—C5—N2—N3 | 175.49 (14) | C19—C18—C23—C22 | 0.9 (3) |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···N2 | 0.93 | 2.75 | 3.024 (2) | 98 |
C23—H23···N2 | 0.93 | 2.51 | 2.796 (2) | 98 |
C11—H11···O2 | 0.93 | 2.81 | 3.028 (2) | 94 |
C17—H17···N1 | 0.93 | 2.55 | 2.842 (3) | 99 |
C20—H20···O4 | 0.93 | 2.44 | 2.718 (2) | 98 |
N3—H3···O4i | 0.86 | 2.43 | 3.183 (2) | 147 |
C7—H7···O2ii | 0.93 | 2.48 | 3.382 (2) | 163 |
Symmetry codes: (i) x+1/2, −y+1/2, z−1/2; (ii) x−1, y, z. |
Experimental details
Crystal data |
Chemical formula | C23H16N4O4 |
Mr | 412.40 |
Crystal system, space group | Monoclinic, P21/n |
Temperature (K) | 293 |
a, b, c (Å) | 5.787 (1), 29.089 (3), 11.881 (1) |
β (°) | 100.49 (1) |
V (Å3) | 1966.6 (4) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 0.10 |
Crystal size (mm) | 0.25 × 0.18 × 0.12 |
|
Data collection |
Diffractometer | Siemens R3m/V diffractometer |
Absorption correction | – |
No. of measured, independent and observed [I > 2σ(I)] reflections | 3739, 3301, 1899 |
Rint | 0.013 |
(sin θ/λ)max (Å−1) | 0.583 |
|
Refinement |
R[F2 > 2σ(F2)], wR(F2), S | 0.034, 0.079, 0.84 |
No. of reflections | 3301 |
No. of parameters | 282 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.23, −0.19 |
Selected geometric parameters (Å, º) topO1—C1 | 1.354 (2) | C4—C5 | 1.476 (2) |
O1—N1 | 1.400 (2) | C5—N2 | 1.302 (2) |
N1—C3 | 1.316 (2) | C5—C6 | 1.489 (2) |
C3—C2 | 1.421 (2) | N2—N3 | 1.343 (2) |
C3—C12 | 1.475 (2) | N3—C18 | 1.386 (2) |
C2—C1 | 1.347 (2) | C21—N4 | 1.449 (2) |
C1—C4 | 1.491 (2) | N4—O3 | 1.222 (2) |
C4—O2 | 1.219 (2) | N4—O4 | 1.229 (2) |
| | | |
C1—O1—N1 | 108.5 (1) | C5—N2—N3 | 118.3 (2) |
C3—N1—O1 | 106.1 (2) | N2—N3—C18 | 120.2 (2) |
N1—C3—C2 | 110.8 (2) | C23—C18—N3 | 122.0 (2) |
N1—C3—C12 | 119.2 (2) | N3—C18—C19 | 118.5 (2) |
C2—C1—O1 | 109.7 (2) | C22—C21—N4 | 119.8 (2) |
O1—C1—C4 | 112.4 (2) | C20—C21—N4 | 119.1 (2) |
O2—C4—C5 | 120.9 (2) | O3—N4—O4 | 122.6 (2) |
O2—C4—C1 | 118.7 (2) | O3—N4—C21 | 118.3 (2) |
N2—C5—C4 | 115.6 (2) | O4—N4—C21 | 119.1 (2) |
N2—C5—C6 | 125.8 (2) | | |
Hydrogen-bond geometry (Å, º) top
D—H···A | D—H | H···A | D···A | D—H···A |
C2—H2···N2 | 0.93 | 2.75 | 3.024 (2) | 98 |
C23—H23···N2 | 0.93 | 2.51 | 2.796 (2) | 98 |
C11—H11···O2 | 0.93 | 2.81 | 3.028 (2) | 94 |
C17—H17···N1 | 0.93 | 2.55 | 2.842 (3) | 99 |
C20—H20···O4 | 0.93 | 2.44 | 2.718 (2) | 98 |
N3—H3···O4i | 0.86 | 2.43 | 3.183 (2) | 147 |
C7—H7···O2ii | 0.93 | 2.48 | 3.382 (2) | 163 |
Symmetry codes: (i) x+1/2, −y+1/2, z−1/2; (ii) x−1, y, z. |
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As part of our investigation into the participation of vicinal groups in the bromination reaction of isoxazole compounds to form bis-heterocyclic spirans, we succeeded in obtaining single crystals, suitable for X-ray crystallography, of the title compound, (I). This compound was formed during the electrophilic bromination of 3-phenyl-p-nitrophenylhydrazone-5-phenacylisoxazole in chloroform. The formation of (I) can be ascribed to a hydrolytic process resulting from the presence of moisture in the reaction medium. \scheme
The structure of (I) is shown in Fig. 1, and selected bond lengths and angles are listed in Table 1. In the following discussion, the molecule will be considered in two fragments: the nitrophenylhydrazone moiety and the isoxazole moiety.
It is remarkable that the E isomer for the nitrophenylhydrazone derivative was formed preferentially over the Z isomer since the latter would almost certainly feature an NH···OC intramolecular hydrogen bond. In (I), the E isomer is stabilized by an intermolecular hydrogen bond involving atoms N2, C23 and C2. The geometric parameters are listed in Table 2. Atoms N3 and O2 are involved in two intermolecular hydrogen interactions that stabilize the molecular packing, N3 with O4i and C7 with O2ii; the geometric parameters are listed in Table 2 [symmetry codes: (i) 1/2 + x, 1/2 − y, z − 1/2; (ii) x − 1, y, z].
The phenylhydrazone fragment is almost planar; geometric calculations show that the maximum distance from the mean plane is 0.077 (2) Å for O4. All geometric parameters concerning the nitrophenylhydrazone fragment of the molecule agree with the values found in the literature for similar compounds (Willey & Drew, 1983; Drew & Willey, 1982; Stankovic et al., 1991; Whitaker, 1987) without an intramolecular hydrogen bond (NH···OC).
In the second fragment, the isoxazole ring is nearly planar; the maximum deviation from the mean plane is 0.010 (2) Å for N1. The angle between the nitrophenylhydrazone plane and the isoxazole plane is 32.94 (6)°, and the phenyl ring is twisted a further 20.48 (8)° from the isoxazole plane. The mutual orientation of the aromatic ring and the isoxazole moiety is due to the presence of an intramolecular hydrogen bond interaction involving N1 and C17 (see Table 2). The values of the C2—C1, C1—C4 and C4—O2 bond lengths (Table 1) show a weak π-electron delocalization with respect to the compound reported by Sundaralingam & Jeffrey (1962). Other geometric parameters are in good agreement with those reported in the literature (Staskun et al., 1991; Smith et al., 1991).
The packing is mainly determined by normal van der Waals interactions and two intermolecular hydrogen bonds involving the N3 and O2 atoms, as discussed above. As can be seen in Fig. 2, the molecules are packed in a head-tail fashion along the a axis.