4-[(3-Phenyl-4,5-di­hydro­isoxazol-5-yl)meth­yl]-2H-benzo[b][1,4]thia­zin-3(4H)-one

Sebbar, N.K.; Ellouz, M.; Essassi, E.M.; Saadi, M.; El Ammari, L.

doi:10.1107/S2414314616010129

organic compounds

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ISSN: 2414-3146

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doi:10.1107/S2414314616010129

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4-[(3-Phenyl-4,5-dihydroisoxazol-5-yl)methyl]-2H-benzo[b][1,4]thiazin-3(4H)-one

Nada Kheira Sebbar,^a ^* Mohamed Ellouz,^a El Mokhtar Essassi,^a Mohamed Saadi ^b and Lahcen El Ammari ^b

^aLaboratoire de Chimie Organique Hétérocyclique URAC 21, Pôle de Compétences Pharmacochimie, Mohammed V University in Rabat, BP 1014 Avenue Ibn Batouta, Rabat, Morocco, and ^bLaboratoire de Chimie du Solide Appliquée, Faculty of Sciences, Mohammed V University in Rabat, Avenue Ibn Battouta, BP 1014, Rabat, Morocco
^*Correspondence e-mail: nk_sebbar@yahoo.fr

Edited by J. Simpson, University of Otago, New Zealand (Received 19 June 2016; accepted 21 June 2016; online 24 June 2016)

In the title compound, C₁₈H₁₆N₂O₂S, the 5-dihydroisoxazol-5-yl ring and its phenyl substituent are nearly coplanar, with the largest deviation from the mean plane being 0.0184 (16) Å. The thiomorpholin-3-one ring adopts a screw-boat conformation and the attached benzene ring makes a dihedral angle of 42.26 (7)° with the mean plane through the 3-phenyl-4,5-dihydroisoxazol-5-yl ring system. In the crystal, molecules are linked by pairs of C—H⋯N hydrogen bonds, forming inversion dimers. These dimers are linked via C—H⋯O hydrogen bonds, generating a three-dimensional network.

Keywords: crystal structure; 2H-benzo[b][1,4]thiazin-3(4H)-one; hydrogen bonds; inversion dimers.

CCDC reference: 1486932

Structure description

1,4-Benzothiazines are a class of medicinally important heterocyclic compounds which are used extensively in drug design. It is well documented that 1,4-benzothiazin-3-one derivatives possess important pharmacological properties and play a vital role in the treatment of neurodegenerative disorders, such as Parkinson's disease and Alzheimer's disease (Shen et al., 1996 ). They can also act as calcium channel blockers (Schwarz et al., 1999 ), phosphodiesterase-7 inhibitors (Castro et al., 2001 ) and anticataract agents (Kawashima et al., 1994 ). Isoxazole derivatives represent a unique class of nitrogen- and oxygen-containing five-membered heterocycles. They are the components of a variety of natural products and medicinally useful compounds (Sperry et al., 2005 ). Isoxazole derivatives with a variety of substituents are known to have various biological activities in both the pharmaceutical and agricultural areas (Lang & Lin, 1984 ; Boyd, 1991 ).

The present work is a continuation of our investigations of new derivatives of 2H-benzo[b][1,4]thiazin-3(4H)-one for their biological activities (Sebbar et al., 2014a ,b ). The nitrile oxide, formed in situ by chlorination of an oxime, reacts with 4-allyl-2H-benzo[b][1,4]thiazin-3(4H)-one in a biphasic medium (water–chloroform) at 0°C over 4 h to afford the unique cycloadduct 4-((3-phenyl-4,5-dihydroisoxazol-5-yl)methyl)-2H-benzo[b] [1,4]thiazin-3(4H)-one.

The molecule of the title compound contains the two fused six-membered rings of the 1,4-benzothiazine unit, linked, through a methylene group, to the 3-phenyl-4,5-dihydroisoxazol-5-yl ring system, as shown in Fig. 1. The dihydroisoxazole and phenyl rings are almost coplanar, as indicated by the dihedral angle of 1.33 (9)° between their planes. The six-membered heterocycle adopts a screw-boat conformation, as indicated by the total puckering amplitude Q_T = 0.6390 (2) Å, and a spherical polar angle θ = 65.02 (1)° with φ = 326.38 (2)°. The dihedral angle between the phenyl (C13–C18) and the benzene (C1–C6) rings is 42.42 (9)°. An intramolecular C5—H5⋯O2 interaction closes a seven-membered ring.

Figure 1
The molecular structure of the title compound, showing the atom-labelling scheme. Displacement ellipsoids are drawn at the 50% probability level. H atoms are represented as small circles of arbitrary radius.

In the crystal, C10—H10⋯N2 hydrogen bonds form inversion dimers, generating R₂²(8) rings. These dimers are further connected by C2—H2⋯O1 hydrogen bonds, forming a three-dimensional network, Fig. 2 and Table 1.

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C10—H10⋯N2ⁱ	0.98	2.64	3.405 (2)	136
C2—H2⋯O1ⁱⁱ	0.93	2.64	3.538 (2)	161
C5—H5⋯O2	0.93	2.43	3.135 (2)	132
Symmetry codes: (i) -x+1, -y+1, -z+1; (ii) $[x-{\script{1\over 2}}, y, -z+{\script{3\over 2}}]$ .

Figure 2
Molecules of the title compound linked by C—H⋯N and C—H⋯O hydrogen bonds forming a three-dimensional network. Hydrogen bonds are shown as blue dashed lines.

Synthesis and crystallization

A 24% sodium hypochlorite solution (10 ml) was added dropwise to a solution of 4-allyl-2H-benzo[b][1,4]thiazin-3(4H)-one (0.5 g, 2.4 mmol) and benzaldoxime (0.52 ml, 4.8 mmol) in chloroform (30 ml) at 0°C. Stirring was continued for 4 h. The organic layer was dried over Na₂SO₄ and the solvent was evaporated under reduced pressure. The residue was then purified by column chromatography on silica gel using a mixture of hexane/ethyl acetate (v/v = 90/10) as eluent. Colourless crystals were isolated when the solvent was allowed to evaporate (yield = 38%, m.p. = 408 K).

Refinement

Crystal data, data collection and structure refinement details are summarized in Table 2.

Table 2
Experimental details

Crystal data
Chemical formula	C₁₈H₁₆N₂O₂S
M_r	324.39
Crystal system, space group	Orthorhombic, Pbca
Temperature (K)	296
a, b, c (Å)	11.7526 (3), 10.4082 (3), 25.5656 (7)
V (Å³)	3127.27 (15)
Z	8
Radiation type	Mo Kα
μ (mm⁻¹)	0.22
Crystal size (mm)	0.35 × 0.31 × 0.22

Data collection
Diffractometer	Bruker X8 APEX
Absorption correction	Multi-scan (SADABS; Bruker, 2009 )
T_min, T_max	0.626, 0.746
No. of measured, independent and observed [I > 2σ(I)] reflections	41764, 4391, 2776
R_int	0.049
(sin θ/λ)_max (Å⁻¹)	0.694

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.042, 0.116, 1.02
No. of reflections	4391
No. of parameters	208
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.18, −0.23
Computer programs: APEX2 and SAINT (Bruker, 2009), SHELXT (Sheldrick, 2015a ), SHELXL2014 (Sheldrick, 2015b ), ORTEPIII (Burnett & Johnson, 1996 ), ORTEP-3 for Windows (Farrugia, 2012 ), Mercury (Macrae et al., 2008 ), PLATON (Spek, 2009 ) and publCIF (Westrip, 2010 ).

Structural data

CCDC reference: 1486932

Crystal structure: contains datablock I. DOI: 10.1107/S2414314616010129/sj4050sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S2414314616010129/sj4050Isup2.hkl

Supporting information file. DOI: 10.1107/S2414314616010129/sj4050Isup3.cml

checkCIF report

Computing details top

Data collection: APEX2 (Bruker, 2009); cell refinement: SAINT (Bruker, 2009); data reduction: SAINT (Bruker, 2009); program(s) used to solve structure: SHELXT (Sheldrick, 2015a); program(s) used to refine structure: SHELXL2014 (Sheldrick, 2015b); molecular graphics: ORTEPIII (Burnett & Johnson, 1996), ORTEP-3 for Windows (Farrugia, 2012) and Mercury (Macrae et al., 2008); software used to prepare material for publication: PLATON (Spek, 2009) and publCIF (Westrip, 2010).

4-[(3-Phenyl-4,5-dihydroisoxazol-5-yl)methyl]-2H-benzo[b][1,4]thiazin-3(4H)-one top

Crystal data top

C₁₈H₁₆N₂O₂S	D_x = 1.378 Mg m⁻³
M_r = 324.39	Mo Kα radiation, λ = 0.71073 Å
Orthorhombic, Pbca	Cell parameters from 4391 reflections
a = 11.7526 (3) Å	θ = 2.7–29.6°
b = 10.4082 (3) Å	µ = 0.22 mm⁻¹
c = 25.5656 (7) Å	T = 296 K
V = 3127.27 (15) Å³	Block, colourless
Z = 8	0.35 × 0.31 × 0.22 mm
F(000) = 1360

Data collection top

Bruker X8 APEX diffractometer	4391 independent reflections
Radiation source: fine-focus sealed tube	2776 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.049
φ and ω scans	θ_max = 29.6°, θ_min = 2.7°
Absorption correction: multi-scan (SADABS; Bruker, 2009)	h = −16→16
T_min = 0.626, T_max = 0.746	k = −14→14
41764 measured reflections	l = −35→35

Refinement top

Refinement on F²	0 restraints
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F² > 2σ(F²)] = 0.042	H-atom parameters constrained
wR(F²) = 0.116	w = 1/[σ²(F_o²) + (0.0471P)² + 0.5946P] where P = (F_o² + 2F_c²)/3
S = 1.02	(Δ/σ)_max = 0.001
4391 reflections	Δρ_max = 0.18 e Å⁻³
208 parameters	Δρ_min = −0.23 e Å⁻³

Special details top

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.

Fractional atomic coordinates and isotropic or equivalent isotropic displacement parameters (Å²) top

	x	y	z	U_iso*/U_eq
C1	0.41617 (14)	0.54751 (16)	0.72451 (6)	0.0523 (4)
C2	0.31872 (17)	0.5156 (2)	0.75261 (7)	0.0697 (5)
H2	0.3001	0.5621	0.7825	0.084*
C3	0.25022 (17)	0.4171 (2)	0.73689 (9)	0.0753 (6)
H3	0.1870	0.3942	0.7567	0.090*
C4	0.27550 (15)	0.3520 (2)	0.69163 (9)	0.0702 (5)
H4	0.2286	0.2853	0.6806	0.084*
C5	0.37013 (13)	0.38471 (16)	0.66217 (7)	0.0542 (4)
H5	0.3846	0.3418	0.6309	0.065*
C6	0.44335 (11)	0.48065 (14)	0.67880 (6)	0.0435 (3)
C7	0.60226 (13)	0.62130 (15)	0.65330 (6)	0.0497 (4)
C8	0.54562 (16)	0.72680 (17)	0.68349 (8)	0.0663 (5)
H8A	0.4789	0.7563	0.6646	0.080*
H8B	0.5975	0.7987	0.6870	0.080*
C9	0.60129 (13)	0.40421 (14)	0.62058 (6)	0.0459 (3)
H9A	0.5695	0.3220	0.6309	0.055*
H9B	0.6818	0.4029	0.6288	0.055*
C10	0.58705 (13)	0.42034 (16)	0.56196 (6)	0.0521 (4)
H10	0.6170	0.5042	0.5512	0.062*
C11	0.64431 (13)	0.31506 (18)	0.53054 (6)	0.0569 (4)
H11A	0.7005	0.3499	0.5066	0.068*
H11B	0.6803	0.2522	0.5531	0.068*
C12	0.54543 (12)	0.25839 (15)	0.50168 (6)	0.0455 (3)
C13	0.55384 (12)	0.15192 (14)	0.46429 (6)	0.0459 (3)
C14	0.65787 (14)	0.09460 (18)	0.45405 (7)	0.0585 (4)
H14	0.7230	0.1232	0.4711	0.070*
C15	0.66500 (17)	−0.00510 (19)	0.41843 (8)	0.0702 (5)
H15	0.7351	−0.0431	0.4116	0.084*
C16	0.56970 (19)	−0.04828 (18)	0.39314 (8)	0.0720 (5)
H16	0.5754	−0.1147	0.3689	0.086*
C17	0.46626 (18)	0.00613 (19)	0.40342 (8)	0.0728 (5)
H17	0.4015	−0.0241	0.3866	0.087*
C18	0.45782 (14)	0.10545 (18)	0.43862 (7)	0.0601 (4)
H18	0.3871	0.1421	0.4454	0.072*
N1	0.54641 (10)	0.50614 (11)	0.65117 (5)	0.0430 (3)
N2	0.45035 (11)	0.31124 (14)	0.51224 (5)	0.0527 (3)
O1	0.69382 (10)	0.63712 (12)	0.63161 (5)	0.0650 (3)
O2	0.46655 (10)	0.41189 (12)	0.54839 (4)	0.0624 (3)
S1	0.50438 (4)	0.67123 (5)	0.74704 (2)	0.07191 (17)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
C1	0.0519 (9)	0.0552 (9)	0.0497 (9)	0.0146 (7)	0.0002 (7)	0.0048 (7)
C2	0.0669 (11)	0.0824 (13)	0.0598 (11)	0.0234 (11)	0.0166 (9)	0.0110 (10)
C3	0.0579 (11)	0.0884 (15)	0.0797 (13)	0.0079 (10)	0.0217 (10)	0.0245 (12)
C4	0.0530 (10)	0.0714 (12)	0.0863 (14)	−0.0099 (9)	0.0019 (9)	0.0188 (11)
C5	0.0497 (8)	0.0538 (9)	0.0592 (10)	−0.0013 (7)	0.0002 (7)	0.0063 (8)
C6	0.0402 (7)	0.0454 (8)	0.0450 (8)	0.0074 (6)	−0.0005 (6)	0.0080 (6)
C7	0.0438 (8)	0.0533 (9)	0.0522 (9)	−0.0016 (7)	−0.0074 (7)	0.0031 (7)
C8	0.0650 (11)	0.0482 (9)	0.0858 (13)	−0.0028 (8)	−0.0004 (10)	−0.0060 (9)
C9	0.0453 (8)	0.0498 (8)	0.0425 (8)	0.0068 (6)	−0.0022 (6)	0.0007 (6)
C10	0.0485 (8)	0.0642 (10)	0.0436 (8)	0.0027 (7)	−0.0028 (7)	0.0009 (7)
C11	0.0413 (8)	0.0835 (12)	0.0459 (8)	0.0013 (8)	−0.0003 (6)	−0.0087 (8)
C12	0.0370 (7)	0.0612 (9)	0.0383 (7)	0.0002 (7)	0.0002 (6)	0.0100 (7)
C13	0.0440 (8)	0.0540 (9)	0.0399 (7)	−0.0026 (7)	0.0017 (6)	0.0103 (7)
C14	0.0474 (9)	0.0698 (11)	0.0583 (10)	−0.0009 (8)	0.0052 (7)	−0.0011 (9)
C15	0.0731 (12)	0.0669 (12)	0.0707 (12)	0.0076 (10)	0.0157 (10)	0.0000 (10)
C16	0.0975 (16)	0.0535 (10)	0.0648 (12)	−0.0091 (10)	0.0013 (11)	−0.0019 (9)
C17	0.0792 (13)	0.0665 (12)	0.0727 (13)	−0.0157 (10)	−0.0147 (10)	0.0011 (10)
C18	0.0491 (9)	0.0676 (11)	0.0637 (11)	−0.0041 (8)	−0.0055 (8)	0.0050 (9)
N1	0.0405 (6)	0.0449 (7)	0.0437 (7)	0.0028 (5)	−0.0012 (5)	0.0003 (5)
N2	0.0446 (7)	0.0686 (9)	0.0450 (7)	0.0067 (6)	−0.0046 (6)	0.0051 (6)
O1	0.0485 (6)	0.0717 (8)	0.0748 (8)	−0.0112 (6)	0.0023 (6)	0.0029 (6)
O2	0.0507 (6)	0.0866 (9)	0.0500 (6)	0.0193 (6)	−0.0083 (5)	−0.0092 (6)
S1	0.0788 (3)	0.0722 (3)	0.0647 (3)	0.0081 (2)	−0.0025 (2)	−0.0221 (2)

Geometric parameters (Å, º) top

C1—C2	1.392 (2)	C9—H9B	0.9700
C1—C6	1.397 (2)	C10—O2	1.4607 (19)
C1—S1	1.7506 (18)	C10—C11	1.516 (2)
C2—C3	1.364 (3)	C10—H10	0.9800
C2—H2	0.9300	C11—C12	1.498 (2)
C3—C4	1.373 (3)	C11—H11A	0.9700
C3—H3	0.9300	C11—H11B	0.9700
C4—C5	1.386 (2)	C12—N2	1.2744 (19)
C4—H4	0.9300	C12—C13	1.467 (2)
C5—C6	1.385 (2)	C13—C14	1.385 (2)
C5—H5	0.9300	C13—C18	1.392 (2)
C6—N1	1.4271 (18)	C14—C15	1.383 (3)
C7—O1	1.2217 (19)	C14—H14	0.9300
C7—N1	1.3677 (19)	C15—C16	1.369 (3)
C7—C8	1.498 (2)	C15—H15	0.9300
C8—S1	1.792 (2)	C16—C17	1.367 (3)
C8—H8A	0.9700	C16—H16	0.9300
C8—H8B	0.9700	C17—C18	1.374 (3)
C9—N1	1.4673 (18)	C17—H17	0.9300
C9—C10	1.517 (2)	C18—H18	0.9300
C9—H9A	0.9700	N2—O2	1.4098 (18)

C2—C1—C6	120.06 (17)	O2—C10—H10	109.6
C2—C1—S1	119.53 (14)	C11—C10—H10	109.6
C6—C1—S1	120.41 (13)	C9—C10—H10	109.6
C3—C2—C1	120.86 (19)	C12—C11—C10	101.61 (12)
C3—C2—H2	119.6	C12—C11—H11A	111.4
C1—C2—H2	119.6	C10—C11—H11A	111.4
C2—C3—C4	119.42 (18)	C12—C11—H11B	111.4
C2—C3—H3	120.3	C10—C11—H11B	111.4
C4—C3—H3	120.3	H11A—C11—H11B	109.3
C3—C4—C5	120.71 (19)	N2—C12—C13	121.56 (14)
C3—C4—H4	119.6	N2—C12—C11	113.95 (14)
C5—C4—H4	119.6	C13—C12—C11	124.49 (13)
C6—C5—C4	120.58 (17)	C14—C13—C18	118.47 (16)
C6—C5—H5	119.7	C14—C13—C12	120.53 (14)
C4—C5—H5	119.7	C18—C13—C12	121.00 (14)
C5—C6—C1	118.28 (14)	C15—C14—C13	120.06 (17)
C5—C6—N1	120.62 (14)	C15—C14—H14	120.0
C1—C6—N1	121.03 (14)	C13—C14—H14	120.0
O1—C7—N1	121.51 (15)	C16—C15—C14	120.51 (18)
O1—C7—C8	121.76 (15)	C16—C15—H15	119.7
N1—C7—C8	116.73 (14)	C14—C15—H15	119.7
C7—C8—S1	110.53 (12)	C17—C16—C15	120.05 (19)
C7—C8—H8A	109.5	C17—C16—H16	120.0
S1—C8—H8A	109.5	C15—C16—H16	120.0
C7—C8—H8B	109.5	C16—C17—C18	120.13 (18)
S1—C8—H8B	109.5	C16—C17—H17	119.9
H8A—C8—H8B	108.1	C18—C17—H17	119.9
N1—C9—C10	113.45 (12)	C17—C18—C13	120.77 (17)
N1—C9—H9A	108.9	C17—C18—H18	119.6
C10—C9—H9A	108.9	C13—C18—H18	119.6
N1—C9—H9B	108.9	C7—N1—C6	123.40 (12)
C10—C9—H9B	108.9	C7—N1—C9	116.36 (12)
H9A—C9—H9B	107.7	C6—N1—C9	120.16 (12)
O2—C10—C11	105.13 (12)	C12—N2—O2	109.95 (12)
O2—C10—C9	109.56 (13)	N2—O2—C10	109.35 (11)
C11—C10—C9	113.23 (13)	C1—S1—C8	95.70 (8)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C10—H10···N2ⁱ	0.98	2.64	3.405 (2)	136
C2—H2···O1ⁱⁱ	0.93	2.64	3.538 (2)	161
C5—H5···O2	0.93	2.43	3.135 (2)	132

Symmetry codes: (i) −x+1, −y+1, −z+1; (ii) x−1/2, y, −z+3/2.

Acknowledgements

The authors thank the Unit of Support for Technical and Scientific Research (UATRS, CNRST) for the X-ray measurements and the University Mohammed V, Rabat, Morocco, for financial support.

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