supplementary materials


kp2448 scheme

Acta Cryst. (2013). E69, o716    [ doi:10.1107/S1600536813009653 ]

rac-3-(4-Chlorophenyl)-3a,4-dihydro-3H-chromeno[4,3-c]isoxazole-3a-carbonitrile

S. Paramasivam, J. Srinivasan, P. R. Seshadri and M. Bakthadoss

Abstract top

The title compound, C17H11ClN2O2, which contains two stereogenic C atoms, crystallizes in a centrosymmetric space group as a racemate. The pyran ring and the isoxazole ring adopt sofa and twisted conformations, respectively. The dihedral angle between the benzene ring and the mean plane through the near coplanar atoms of the pyran ring is 4.17 (5)°. The molecular conformation features a weak C-H...O contact. In the crystal, C-H...O hydrogen bonds link the molecules, forming chains along the a-axis direction.

Comment top

As a continuation of our research related to isoxazole containing chromenoisoxazole moiety, we analysed the crystal structure of rac-6-Ethoxy-3,3a,4,9 b-tetrahydro-1,3- diphenyl-1H-chromeno[4,3-c]isoxazole- 3a-carbonitrile (Paramasivam et al., 2012). The present compound exhibits the pronounced similarity to the previous ones, either in bond lengths and angles as well as in molecular conformations.

Isoxazole derivative exhibit anti-fungal (Mullen et al., 1988) and anti-consulvant (Eddington et al., 2002) activities whereas benzopyran and chromenopyrrole derivatives exhibit anti-HIV activities (Kashiwada et al., 2001) and used in the treatment of impulsive-disorder disease (Caine, 1993). On these grounds, the title compound was chosen for X-ray structure analysis (Fig.1).

The pyran ring (O2/C1/C6—C9) adopts a sofa conformation with the puckering parameters (Cremer & Pople, 1975) being q2=0.359 (1) Å, q3=-0.292 (1) Å, QT=0.463 (1) Å and the five-membered isoxazole ring (N1/O1/C7/C8/C11) adopts an envelope conformation with puckering parameters (Cremer & Pople, 1975) being q2=0.284 (1) Å and Φ2=142.4 (3)°.

The dihedral angle between the pyran and the benzene rings (C1—C6) is 4.17 (5)°. The dihedral angle between the chromeno ring (fusion of benzene and pyran rings) and isoxazole ring is 13.42 (5)°. In the chromenoisoxazole moiety, the dihedral angle between the benzene and isoxazole ring is 10.83 (5)° and the dihedral angle between the pyran and isoxazole ring is 14.81 (5)°.

The geometric parameters of the title compound (Fig. 1) agree well with the reported ones of similar structures (Paramasivam et al., 2012).

The molecular structure is stabilized by C—H···O intramolecular interaction and the crystal packing is stabilized by C—H···O hydrogen bonds (Table 1).

Related literature top

For the biological activity of isoxazole derivatives, see: Mullen et al. (1988); Eddington et al. (2002); Kashiwada et al. (2001); Caine (1993). For a related structure, see: Paramasivam et al. (2012). For conformational analysis and pukering parameters, see: Cremer & Pople (1975).

Experimental top

A solution of (E)-3-(4-chlorophenyl)-2-((2-((E)-(hydroxyimino)methyl)phenoxy)methyl) acrylonitrile (2 mmol) in CCl4 at (273–283 K) was added pinch wise NCS (4 mmol) over 3 h. After Et3N (4 mmol) was added the reaction mixture was stirred at room temperature for 2 h. After completion of the reaction, reaction mixture was evaporated under reduced pressure and the resulting crude mass was diluted with water (15 mL) and extracted with ethyl acetate (3 × 15 mL). The combining organic layer was washed with brine (2 × 10 mL) and dried over anhydrous Na2SO4. The organic layer was evaporated and purified by column chromatography (silica gel 60–120 mesh 7% EtOAc in hexanes) to provide the desired pure product 3-(4-chlorophenyl)-3a,4-dihydro-3H-chromeno[4,3-c]isoxazole-3a-carbonitrile a as colourless solid.

Refinement top

Hydrogen atoms were positioned geometrically and allowed to ride on their parent atoms, with C—H = 0.93 - 0.97 Å and Uiso(H) = 1.5Ueq(C) for methyl H atoms and 1.2 Ueq(C) for other H atoms.

Computing details top

Data collection: APEX2 (Bruker, 2008); cell refinement: SAINT (Bruker, 2008); data reduction: SAINT (Bruker, 2008); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 for Windows (Farrugia, 2012) and PLATON (Spek, 2009); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008), PLATON (Spek, 2009) and publCIF (Westrip, 2010).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title compound, showing the atom-numbering scheme and displacement ellipsoids drawn at the 20% probability level.
rac-3-(4-Chlorophenyl)-3a,4-dihydro-3H-chromeno[4,3-c]isoxazole-3a-carbonitrile top
Crystal data top
C17H11ClN2O2F(000) = 640
Mr = 310.73Monoclinic
Monoclinic, P21/cDx = 1.459 Mg m3
Hall symbol: -P 2ybcMo Kα radiation, λ = 0.71073 Å
a = 6.7891 (2) ÅCell parameters from 3541 reflections
b = 13.9921 (3) Åθ = 2.0–28.4°
c = 15.1788 (3) ŵ = 0.28 mm1
β = 101.175 (1)°T = 298 K
V = 1414.55 (6) Å3Block, colourless
Z = 40.30 × 0.25 × 0.20 mm
Data collection top
Bruker SMART APEXII area-detector
diffractometer
3541 independent reflections
Radiation source: fine-focus sealed tube2865 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.021
ω and φ scansθmax = 28.4°, θmin = 2.0°
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
h = 98
Tmin = 0.921, Tmax = 0.946k = 1811
13620 measured reflectionsl = 2020
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.042Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.132H-atom parameters constrained
S = 1.00 w = 1/[σ2(Fo2) + (0.0796P)2 + 0.2931P]
where P = (Fo2 + 2Fc2)/3
3541 reflections(Δ/σ)max < 0.001
199 parametersΔρmax = 0.24 e Å3
0 restraintsΔρmin = 0.37 e Å3
Crystal data top
C17H11ClN2O2V = 1414.55 (6) Å3
Mr = 310.73Z = 4
Monoclinic, P21/cMo Kα radiation
a = 6.7891 (2) ŵ = 0.28 mm1
b = 13.9921 (3) ÅT = 298 K
c = 15.1788 (3) Å0.30 × 0.25 × 0.20 mm
β = 101.175 (1)°
Data collection top
Bruker SMART APEXII area-detector
diffractometer
3541 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2008)
2865 reflections with I > 2σ(I)
Tmin = 0.921, Tmax = 0.946Rint = 0.021
13620 measured reflectionsθmax = 28.4°
Refinement top
R[F2 > 2σ(F2)] = 0.042H-atom parameters constrained
wR(F2) = 0.132Δρmax = 0.24 e Å3
S = 1.00Δρmin = 0.37 e Å3
3541 reflectionsAbsolute structure: ?
199 parametersFlack parameter: ?
0 restraintsRogers parameter: ?
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 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
C10.7698 (2)0.37043 (10)0.51654 (9)0.0382 (3)
C20.7964 (3)0.34701 (12)0.60681 (10)0.0497 (4)
H20.68800.34730.63600.060*
C30.9865 (3)0.32316 (13)0.65285 (10)0.0565 (4)
H31.00520.30660.71320.068*
C41.1478 (3)0.32362 (12)0.61050 (11)0.0551 (4)
H41.27470.30770.64240.066*
C51.1226 (2)0.34766 (11)0.52083 (11)0.0457 (3)
H51.23260.34830.49260.055*
C60.9322 (2)0.37097 (9)0.47255 (9)0.0360 (3)
C70.89137 (18)0.39271 (10)0.37728 (9)0.0350 (3)
C80.67441 (18)0.39375 (10)0.32830 (8)0.0330 (3)
C90.5486 (2)0.43971 (11)0.38997 (9)0.0402 (3)
H9A0.58830.50590.40080.048*
H9B0.40790.43840.36130.048*
C100.6106 (2)0.29492 (11)0.30501 (8)0.0383 (3)
C110.7019 (2)0.45257 (10)0.24579 (9)0.0382 (3)
H110.68900.52060.25920.046*
C120.5619 (2)0.42986 (10)0.15911 (8)0.0369 (3)
C130.6257 (3)0.38630 (11)0.08816 (10)0.0459 (3)
H130.76030.37010.09330.055*
C140.4913 (3)0.36634 (11)0.00910 (11)0.0533 (4)
H140.53530.33780.03900.064*
C150.2925 (3)0.38934 (12)0.00299 (10)0.0509 (4)
C160.2244 (3)0.43228 (14)0.07288 (11)0.0553 (4)
H160.08910.44700.06790.066*
C170.3603 (2)0.45313 (13)0.15060 (10)0.0490 (4)
H170.31620.48320.19790.059*
N11.01637 (18)0.41374 (11)0.32770 (8)0.0479 (3)
N20.5647 (2)0.21792 (11)0.28725 (9)0.0577 (4)
O10.90826 (15)0.43321 (10)0.23971 (7)0.0530 (3)
O20.57595 (15)0.38915 (8)0.47380 (7)0.0463 (3)
Cl10.12337 (10)0.36499 (4)0.09593 (3)0.0808 (2)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
C10.0393 (7)0.0430 (7)0.0311 (6)0.0037 (5)0.0038 (5)0.0036 (5)
C20.0611 (10)0.0557 (9)0.0320 (7)0.0063 (7)0.0085 (6)0.0012 (6)
C30.0750 (12)0.0552 (10)0.0329 (7)0.0091 (8)0.0050 (7)0.0026 (6)
C40.0534 (9)0.0536 (9)0.0478 (8)0.0034 (7)0.0161 (7)0.0026 (7)
C50.0364 (7)0.0490 (8)0.0469 (8)0.0039 (6)0.0034 (6)0.0004 (6)
C60.0344 (6)0.0382 (7)0.0330 (6)0.0043 (5)0.0005 (5)0.0019 (5)
C70.0275 (6)0.0414 (7)0.0353 (6)0.0025 (5)0.0041 (5)0.0016 (5)
C80.0282 (6)0.0424 (7)0.0279 (5)0.0019 (5)0.0040 (4)0.0002 (5)
C90.0333 (6)0.0547 (8)0.0323 (6)0.0039 (6)0.0059 (5)0.0008 (6)
C100.0384 (7)0.0481 (8)0.0273 (5)0.0052 (6)0.0040 (5)0.0014 (5)
C110.0353 (7)0.0451 (7)0.0343 (6)0.0034 (5)0.0073 (5)0.0030 (5)
C120.0418 (7)0.0389 (7)0.0298 (6)0.0008 (5)0.0064 (5)0.0056 (5)
C130.0528 (9)0.0471 (8)0.0391 (7)0.0062 (6)0.0120 (6)0.0014 (6)
C140.0770 (12)0.0459 (9)0.0366 (7)0.0024 (8)0.0102 (7)0.0040 (6)
C150.0699 (11)0.0439 (8)0.0331 (7)0.0089 (7)0.0049 (7)0.0075 (6)
C160.0475 (9)0.0734 (11)0.0413 (8)0.0023 (8)0.0009 (6)0.0090 (7)
C170.0445 (8)0.0679 (10)0.0334 (7)0.0071 (7)0.0049 (6)0.0014 (6)
N10.0330 (6)0.0693 (9)0.0407 (6)0.0043 (6)0.0055 (5)0.0062 (6)
N20.0748 (10)0.0515 (8)0.0436 (7)0.0157 (7)0.0038 (7)0.0009 (6)
O10.0353 (5)0.0865 (9)0.0387 (5)0.0052 (5)0.0106 (4)0.0121 (5)
O20.0362 (5)0.0721 (7)0.0316 (5)0.0020 (5)0.0095 (4)0.0032 (4)
Cl10.1073 (5)0.0743 (4)0.0450 (3)0.0153 (3)0.0245 (3)0.0034 (2)
Geometric parameters (Å, º) top
C1—O21.3750 (17)C9—H9A0.9700
C1—C21.3863 (19)C9—H9B0.9700
C1—C61.396 (2)C10—N21.139 (2)
C2—C31.384 (3)C11—O11.4477 (17)
C2—H20.9300C11—C121.5001 (18)
C3—C41.373 (3)C11—H110.9800
C3—H30.9300C12—C131.378 (2)
C4—C51.380 (2)C12—C171.388 (2)
C4—H40.9300C13—C141.388 (2)
C5—C61.3953 (19)C13—H130.9300
C5—H50.9300C14—C151.373 (3)
C6—C71.4509 (18)C14—H140.9300
C7—N11.2731 (18)C15—C161.375 (3)
C7—C81.5160 (17)C15—Cl11.7380 (16)
C8—C101.4716 (19)C16—C171.381 (2)
C8—C91.5264 (18)C16—H160.9300
C8—C111.5398 (18)C17—H170.9300
C9—O21.4361 (17)N1—O11.4202 (16)
O2—C1—C2116.15 (13)C8—C9—H9B109.6
O2—C1—C6123.10 (12)H9A—C9—H9B108.1
C2—C1—C6120.71 (14)N2—C10—C8178.78 (16)
C3—C2—C1119.08 (15)O1—C11—C12111.15 (11)
C3—C2—H2120.5O1—C11—C8102.89 (10)
C1—C2—H2120.5C12—C11—C8116.37 (11)
C4—C3—C2120.85 (15)O1—C11—H11108.7
C4—C3—H3119.6C12—C11—H11108.7
C2—C3—H3119.6C8—C11—H11108.7
C3—C4—C5120.35 (15)C13—C12—C17118.99 (13)
C3—C4—H4119.8C13—C12—C11122.50 (13)
C5—C4—H4119.8C17—C12—C11118.51 (12)
C4—C5—C6119.99 (15)C12—C13—C14120.73 (15)
C4—C5—H5120.0C12—C13—H13119.6
C6—C5—H5120.0C14—C13—H13119.6
C1—C6—C5119.01 (13)C15—C14—C13118.96 (15)
C1—C6—C7117.50 (12)C15—C14—H14120.5
C5—C6—C7123.45 (13)C13—C14—H14120.5
N1—C7—C6128.10 (12)C14—C15—C16121.56 (15)
N1—C7—C8113.80 (12)C14—C15—Cl1119.25 (13)
C6—C7—C8118.09 (11)C16—C15—Cl1119.19 (15)
C10—C8—C7108.77 (11)C15—C16—C17118.86 (16)
C10—C8—C9111.69 (11)C15—C16—H16120.6
C7—C8—C9108.02 (10)C17—C16—H16120.6
C10—C8—C11112.54 (11)C16—C17—C12120.89 (15)
C7—C8—C1198.32 (10)C16—C17—H17119.6
C9—C8—C11116.36 (12)C12—C17—H17119.6
O2—C9—C8110.13 (11)C7—N1—O1108.55 (11)
O2—C9—H9A109.6N1—O1—C11107.83 (10)
C8—C9—H9A109.6C1—O2—C9117.36 (11)
O2—C9—H9B109.6
O2—C1—C2—C3177.14 (15)C9—C8—C11—O1141.41 (12)
C6—C1—C2—C30.6 (2)C10—C8—C11—C1233.88 (17)
C1—C2—C3—C40.8 (3)C7—C8—C11—C12148.26 (12)
C2—C3—C4—C50.2 (3)C9—C8—C11—C1296.82 (15)
C3—C4—C5—C60.5 (3)O1—C11—C12—C136.67 (19)
O2—C1—C6—C5177.67 (13)C8—C11—C12—C13110.64 (16)
C2—C1—C6—C50.1 (2)O1—C11—C12—C17173.80 (13)
O2—C1—C6—C70.2 (2)C8—C11—C12—C1768.89 (18)
C2—C1—C6—C7177.75 (13)C17—C12—C13—C140.4 (2)
C4—C5—C6—C10.6 (2)C11—C12—C13—C14179.89 (14)
C4—C5—C6—C7177.06 (14)C12—C13—C14—C151.0 (2)
C1—C6—C7—N1166.36 (15)C13—C14—C15—C160.6 (3)
C5—C6—C7—N115.9 (2)C13—C14—C15—Cl1179.77 (12)
C1—C6—C7—C811.99 (18)C14—C15—C16—C170.5 (3)
C5—C6—C7—C8165.74 (13)Cl1—C15—C16—C17178.73 (13)
N1—C7—C8—C1099.59 (14)C15—C16—C17—C121.1 (3)
C6—C7—C8—C1081.84 (14)C13—C12—C17—C160.7 (2)
N1—C7—C8—C9139.02 (14)C11—C12—C17—C16178.84 (15)
C6—C7—C8—C939.55 (16)C6—C7—N1—O1177.66 (13)
N1—C7—C8—C1117.73 (16)C8—C7—N1—O10.74 (18)
C6—C7—C8—C11160.85 (12)C7—N1—O1—C1118.43 (17)
C10—C8—C9—O263.03 (14)C12—C11—O1—N1153.97 (12)
C7—C8—C9—O256.54 (15)C8—C11—O1—N128.73 (14)
C11—C8—C9—O2165.87 (11)C2—C1—O2—C9162.27 (13)
C10—C8—C11—O187.89 (13)C6—C1—O2—C920.0 (2)
C7—C8—C11—O126.48 (13)C8—C9—O2—C148.97 (17)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C13—H13···O10.932.422.7733 (19)102
C5—H5···O2i0.932.473.3422 (19)156
Symmetry code: (i) x+1, y, z.
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C13—H13···O10.932.422.7733 (19)102.4
C5—H5···O2i0.932.473.3422 (19)156.2
Symmetry code: (i) x+1, y, z.
Acknowledgements top

The authors acknowledge the Technology Business Incubator (TBI), CAS in Crystallography, University of Madras, Chennai 600 025, India, for the data collection.

references
References top

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