4-Benzyl-7-chloro-2H-1,4-benz­oxazin-3(4H)-one

Li, Z.-B.; Yang, H.; Xie, Y.-S.; Zhao, C.-G.

doi:10.1107/S1600536809012586

organic compounds

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ISSN: 2056-9890

Volume 65| Part 5| May 2009| Page o1019

doi:10.1107/S1600536809012586

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4-Benzyl-7-chloro-2H-1,4-benzoxazin-3(4H)-one

Zhu-Bo Li,^a ^* Hao Yang,^b Yong-Sheng Xie ^c and Chen-Guang Zhao ^a

^aCollege of Pharmaceutical Sciences, Southwest University, Chongqing 400715, People's Republic of China, ^bCollege of Horticulture and Landscape Architecture, Southwest University, Chongqing 400715, People's Republic of China, and ^cSchool of Chemistry & Chemical Engineering, Shandong University, Jinan 250100, People's Republic of China
^*Correspondence e-mail: lizhubo2007@163.com

(Received 13 March 2009; accepted 3 April 2009; online 10 April 2009)

In the title compound, C₁₅H₁₂ClNO₂, the two benzene rings are nearly perpendicular to each other [dihedral angle = 89.99 (13)°]. The O atom of the six-membered heterocyclic ring is disordered over two sites in a ratio of 0.46 (4):0.54 (4) and is displaced from the mean plane formed by other five atoms, resulting an envelope conformation of the six-membered hetercycle ring.

Related literature

For the biological activity of benzo[b][1,4]oxazin-3(4H)-ones, see: Frechette & Weidner-Wells (1997 ); Maag et al. (2004 ). For the synthesis of benzo[b][1,4]oxazin-3(4H)-ones, see: Zuo et al. (2008 ). For a related structure, see: Cao et al. (2004 ).

Experimental

Crystal data

C₁₅H₁₂ClNO₂
M_r = 273.71
Monoclinic, P 2₁ /c
a = 5.0894 (11) Å
b = 12.630 (3) Å
c = 20.070 (4) Å
β = 91.833 (4)°
V = 1289.4 (5) Å³
Z = 4
Mo Kα radiation
μ = 0.29 mm⁻¹
T = 298 K
0.16 × 0.14 × 0.10 mm

Data collection

Bruker SMART CCD area-detector diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2005 ) T_min = 0.955, T_max = 0.971
6606 measured reflections
2268 independent reflections
1402 reflections with I > 2σ(I)
R_int = 0.031

Refinement

R[F² > 2σ(F²)] = 0.044
wR(F²) = 0.121
S = 1.02
2268 reflections
182 parameters
H-atom parameters constrained
Δρ_max = 0.18 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Data collection: SMART (Bruker 2005); cell refinement: SAINT (Bruker 2005); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks I, New_Global_Publ_Block. DOI: 10.1107/S1600536809012586/xu2496sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809012586/xu2496Isup2.hkl

checkCIF report

Comment top

Benzo[b][1,4]oxazin-3(4H)-ones are an important class of heteroaromatic ring systems that have shown to exhibit a wide range of biological activities such as antimicrobial (Frechette & Weidner-Wells, 1997) and selective 5-HT6 antagonistic activities (Maag et al., 2004). Due to its extensive biological application, the efficient synthesis of benzo[b][1,4]oxazin-3(4H)-ones has recently received much attention (Zuo et al., 2008). We report here the crystal structure of the title compound (Fig. 1). All bond lengths and angles are normal. The dihedral angle between the two benzene rings is 89.99 (13)°. The crystal packing is mainly stabilized by van der Waals interactions. In the title compound the six-membered heterocyclic ring is envelope conformation while in the related compound (Cao et al., 2004) it adopts a screw-boat conformation.

Related literature top

For the biological activity of benzo[b][1,4]oxazin-3(4H)-ones, see: Frechette & Weidner-Wells (1997); Maag et al. (2004). For the synthesis of benzo[b][1,4]oxazin-3(4H)-ones, see: Zuo et al. (2008). For a related structure, see: Cao et al. (2004).

Experimental top

To the solution of N-benzyl-2-(2,4-dichlorophenoxy)acetamide (0.620 g, 2.0 mmol) in DMF (20 ml), caesium carbonate (0.787 g, 2.4 mmol) was added. The mixture was refluxed for 2 h. After completion of the reaction (by TLC monitoring), the DMF was removed under vacuum. Water (20 ml) was added into the residue to obtain a turbid solution and it was extracted by ethyl acetate (20 ml x 4). The combined organic layer was washed by 1 mol/L of hydrochloric acid (10 ml x 3) and saturated sodium chloride solution (10 ml x 3), dried over MgSO₄. And then the mixture was filtered and the filtrate was concentrated under reduced pressure to obtain the corresponding crude product. The product was purified by column chromatography on silica gel using ethyl acetate/hexane = 1/5 as eluent (yield 70%). Crystals suitable for X-ray diffraction were obtained by slow evaporation of a solution of the solid dissolved in ethyl acetate/hexane at room temperature for 10 days.

Computing details top

Data collection: SMART (Bruker 2005); cell refinement: SAINT (Bruker 2005); data reduction: SAINT (Bruker 2005); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: XP in SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

Fig. 1. The molecular structure of the title compound, showing displacement ellipsoids drawn at the 50% probability level.

4-Benzyl-7-chloro-2H-1,4-benzoxazin-3(4H)-one top

Crystal data top

C₁₅H₁₂ClNO₂	F(000) = 568
M_r = 273.71	D_x = 1.410 Mg m⁻³
Monoclinic, P2₁/c	Mo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybc	Cell parameters from 1156 reflections
a = 5.0894 (11) Å	θ = 2.6–20.8°
b = 12.630 (3) Å	µ = 0.29 mm⁻¹
c = 20.070 (4) Å	T = 298 K
β = 91.833 (4)°	Block, colorless
V = 1289.4 (5) Å³	0.16 × 0.14 × 0.10 mm
Z = 4

Data collection top

Bruker SMART CCD area-detector diffractometer	2268 independent reflections
Radiation source: fine-focus sealed tube	1402 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.031
ϕ and ω scans	θ_max = 25.1°, θ_min = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 2005)	h = −6→6
T_min = 0.955, T_max = 0.971	k = −15→10
6606 measured reflections	l = −23→22

Refinement top

Refinement on F²	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Secondary atom site location: difference Fourier map
R[F² > 2σ(F²)] = 0.044	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.121	H-atom parameters constrained
S = 1.02	w = 1/[σ²(F_o²) + (0.0527P)² + 0.1942P] where P = (F_o² + 2F_c²)/3
2268 reflections	(Δ/σ)_max < 0.001
182 parameters	Δρ_max = 0.18 e Å⁻³
0 restraints	Δρ_min = −0.21 e Å⁻³

Crystal data top

C₁₅H₁₂ClNO₂	V = 1289.4 (5) Å³
M_r = 273.71	Z = 4
Monoclinic, P2₁/c	Mo Kα radiation
a = 5.0894 (11) Å	µ = 0.29 mm⁻¹
b = 12.630 (3) Å	T = 298 K
c = 20.070 (4) Å	0.16 × 0.14 × 0.10 mm
β = 91.833 (4)°

Data collection top

Bruker SMART CCD area-detector diffractometer	2268 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2005)	1402 reflections with I > 2σ(I)
T_min = 0.955, T_max = 0.971	R_int = 0.031
6606 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.044	0 restraints
wR(F²) = 0.121	H-atom parameters constrained
S = 1.02	Δρ_max = 0.18 e Å⁻³
2268 reflections	Δρ_min = −0.21 e Å⁻³
182 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 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

	x	y	z	U_iso*/U_eq	Occ. (<1)
Cl1	1.04449 (14)	0.70775 (6)	0.03801 (4)	0.0845 (3)
O1	−0.0247 (4)	0.38796 (16)	0.23334 (10)	0.0903 (6)
O2	0.459 (4)	0.4090 (11)	0.1102 (14)	0.079 (4)	0.46 (4)
O2'	0.358 (5)	0.4386 (16)	0.0928 (5)	0.085 (4)	0.54 (4)
N1	0.2417 (4)	0.52888 (17)	0.21372 (9)	0.0620 (5)
C1	0.8090 (5)	0.6568 (2)	0.09015 (12)	0.0620 (7)
C2	0.6971 (5)	0.5605 (2)	0.07550 (13)	0.0723 (7)
H2	0.7454	0.5233	0.0378	0.087*
C3	0.5134 (5)	0.5196 (2)	0.11685 (13)	0.0679 (7)
C4	0.4348 (5)	0.57338 (19)	0.17315 (11)	0.0567 (6)
C5	0.5528 (6)	0.6694 (2)	0.18658 (13)	0.0715 (8)
H5	0.5058	0.7070	0.2242	0.086*
C6	0.7390 (6)	0.7116 (2)	0.14561 (14)	0.0765 (8)
H6	0.8161	0.7767	0.1556	0.092*
C7	0.2299 (8)	0.3790 (2)	0.13820 (16)	0.0967 (10)
H7A	0.2446	0.3040	0.1481	0.116*	0.46 (4)
H7B	0.0913	0.3865	0.1042	0.116*	0.46 (4)
H7'A	0.3253	0.3162	0.1528	0.116*	0.54 (4)
H7'B	0.0757	0.3544	0.1131	0.116*	0.54 (4)
C8	0.1376 (6)	0.4322 (2)	0.19949 (14)	0.0713 (7)
C9	0.1563 (5)	0.5849 (2)	0.27351 (12)	0.0673 (7)
H9A	−0.0118	0.5564	0.2862	0.081*
H9B	0.1306	0.6591	0.2626	0.081*
C10	0.3484 (4)	0.57652 (19)	0.33223 (11)	0.0534 (6)
C11	0.5208 (5)	0.4939 (2)	0.34046 (13)	0.0684 (7)
H11	0.5248	0.4407	0.3085	0.082*
C12	0.6897 (6)	0.4889 (2)	0.39610 (16)	0.0849 (9)
H12	0.8071	0.4328	0.4010	0.102*
C13	0.6842 (6)	0.5657 (3)	0.44339 (14)	0.0797 (8)
H13	0.7962	0.5616	0.4808	0.096*
C14	0.5167 (6)	0.6478 (3)	0.43615 (14)	0.0819 (9)
H14	0.5142	0.7007	0.4683	0.098*
C15	0.3484 (5)	0.6531 (2)	0.38073 (14)	0.0748 (8)
H15	0.2327	0.7098	0.3763	0.090*

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Cl1	0.0817 (5)	0.0935 (6)	0.0780 (5)	−0.0153 (4)	0.0008 (4)	0.0149 (4)
O1	0.0999 (15)	0.0831 (13)	0.0889 (14)	−0.0188 (12)	0.0197 (12)	0.0042 (11)
O2	0.081 (6)	0.055 (5)	0.103 (8)	−0.012 (4)	0.024 (6)	−0.024 (5)
O2'	0.111 (9)	0.085 (6)	0.062 (3)	−0.030 (6)	0.014 (4)	−0.019 (3)
N1	0.0640 (13)	0.0662 (13)	0.0556 (12)	−0.0020 (11)	−0.0015 (10)	−0.0049 (10)
C1	0.0630 (16)	0.0635 (16)	0.0585 (15)	−0.0031 (13)	−0.0109 (13)	0.0075 (13)
C2	0.0794 (18)	0.0759 (19)	0.0618 (16)	−0.0103 (15)	0.0068 (14)	−0.0117 (14)
C3	0.0764 (18)	0.0629 (16)	0.0642 (16)	−0.0124 (14)	−0.0004 (14)	−0.0120 (14)
C4	0.0628 (15)	0.0569 (15)	0.0497 (14)	−0.0002 (13)	−0.0074 (12)	0.0003 (12)
C5	0.098 (2)	0.0594 (16)	0.0570 (15)	−0.0021 (15)	0.0018 (15)	−0.0067 (13)
C6	0.099 (2)	0.0597 (16)	0.0709 (18)	−0.0122 (16)	−0.0035 (16)	0.0018 (15)
C7	0.135 (3)	0.0709 (19)	0.085 (2)	−0.024 (2)	0.028 (2)	−0.0136 (18)
C8	0.0770 (19)	0.0689 (18)	0.0678 (17)	−0.0049 (16)	−0.0007 (15)	0.0044 (15)
C9	0.0586 (15)	0.0778 (18)	0.0653 (16)	0.0050 (13)	0.0013 (13)	−0.0107 (14)
C10	0.0501 (14)	0.0603 (15)	0.0501 (13)	0.0006 (12)	0.0070 (11)	0.0018 (12)
C11	0.0787 (18)	0.0624 (16)	0.0640 (17)	0.0060 (14)	0.0017 (14)	0.0003 (13)
C12	0.094 (2)	0.075 (2)	0.085 (2)	0.0196 (16)	−0.0067 (18)	0.0158 (17)
C13	0.086 (2)	0.094 (2)	0.0594 (17)	−0.0009 (18)	−0.0062 (14)	0.0101 (17)
C14	0.083 (2)	0.097 (2)	0.0655 (18)	−0.0023 (18)	−0.0002 (16)	−0.0212 (17)
C15	0.0673 (17)	0.0811 (19)	0.0758 (18)	0.0175 (14)	0.0001 (15)	−0.0147 (16)

Geometric parameters (Å, º) top

Cl1—C1	1.739 (3)	C7—H7A	0.9700
O1—C8	1.222 (3)	C7—H7B	0.9700
O2—C7	1.363 (11)	C7—H7'A	0.9700
O2—C3	1.429 (11)	C7—H7'B	0.9700
O2'—C7	1.363 (9)	C9—C10	1.511 (3)
O2'—C3	1.372 (9)	C9—H9A	0.9700
N1—C8	1.357 (3)	C9—H9B	0.9700
N1—C4	1.413 (3)	C10—C11	1.370 (3)
N1—C9	1.471 (3)	C10—C15	1.372 (3)
C1—C6	1.368 (4)	C11—C12	1.389 (4)
C1—C2	1.370 (3)	C11—H11	0.9300
C2—C3	1.371 (3)	C12—C13	1.357 (4)
C2—H2	0.9300	C12—H12	0.9300
C3—C4	1.388 (3)	C13—C14	1.348 (4)
C4—C5	1.376 (3)	C13—H13	0.9300
C5—C6	1.381 (4)	C14—C15	1.384 (4)
C5—H5	0.9300	C14—H14	0.9300
C6—H6	0.9300	C15—H15	0.9300
C7—C8	1.491 (4)

C7—O2—C3	113.6 (7)	O2'—C7—H7'A	114.1
C7—O2'—C3	117.4 (6)	C8—C7—H7'A	106.6
C8—N1—C4	120.7 (2)	H7B—C7—H7'A	129.7
C8—N1—C9	118.7 (2)	O2—C7—H7'B	124.2
C4—N1—C9	120.5 (2)	O2'—C7—H7'B	103.0
C6—C1—C2	120.4 (3)	C8—C7—H7'B	107.6
C6—C1—Cl1	120.3 (2)	H7A—C7—H7'B	81.4
C2—C1—Cl1	119.3 (2)	H7'A—C7—H7'B	106.6
C1—C2—C3	119.4 (2)	O1—C8—N1	124.1 (3)
C1—C2—H2	120.3	O1—C8—C7	119.3 (3)
C3—C2—H2	120.3	N1—C8—C7	116.6 (3)
C2—C3—O2'	117.7 (5)	N1—C9—C10	113.70 (19)
C2—C3—C4	121.9 (2)	N1—C9—H9A	108.8
O2'—C3—C4	118.2 (8)	C10—C9—H9A	108.8
C2—C3—O2	116.5 (5)	N1—C9—H9B	108.8
C4—C3—O2	119.5 (8)	C10—C9—H9B	108.8
C5—C4—C3	117.1 (2)	H9A—C9—H9B	107.7
C5—C4—N1	123.0 (2)	C11—C10—C15	117.8 (2)
C3—C4—N1	119.9 (2)	C11—C10—C9	122.9 (2)
C4—C5—C6	121.8 (3)	C15—C10—C9	119.3 (2)
C4—C5—H5	119.1	C10—C11—C12	120.6 (3)
C6—C5—H5	119.1	C10—C11—H11	119.7
C1—C6—C5	119.4 (3)	C12—C11—H11	119.7
C1—C6—H6	120.3	C13—C12—C11	120.2 (3)
C5—C6—H6	120.3	C13—C12—H12	119.9
O2—C7—C8	120.6 (7)	C11—C12—H12	119.9
O2'—C7—C8	118.1 (8)	C14—C13—C12	120.1 (3)
O2—C7—H7A	107.2	C14—C13—H13	120.0
O2'—C7—H7A	129.9	C12—C13—H13	120.0
C8—C7—H7A	107.2	C13—C14—C15	119.8 (3)
O2—C7—H7B	107.2	C13—C14—H14	120.1
O2'—C7—H7B	80.1	C15—C14—H14	120.1
C8—C7—H7B	107.2	C10—C15—C14	121.5 (3)
H7A—C7—H7B	106.8	C10—C15—H15	119.3
O2—C7—H7'A	85.8	C14—C15—H15	119.3

C6—C1—C2—C3	0.2 (4)	C4—C5—C6—C1	0.0 (4)
Cl1—C1—C2—C3	179.3 (2)	C3—O2—C7—O2'	60.5 (13)
C1—C2—C3—O2'	163.7 (15)	C3—O2—C7—C8	−34 (3)
C1—C2—C3—C4	0.6 (4)	C3—O2'—C7—O2	−69.5 (14)
C1—C2—C3—O2	−163.1 (15)	C3—O2'—C7—C8	34 (3)
C7—O2'—C3—C2	162.2 (16)	C4—N1—C8—O1	178.0 (2)
C7—O2'—C3—C4	−34 (3)	C9—N1—C8—O1	0.1 (4)
C7—O2'—C3—O2	66.7 (14)	C4—N1—C8—C7	−2.3 (4)
C7—O2—C3—C2	−162.9 (15)	C9—N1—C8—C7	179.8 (2)
C7—O2—C3—O2'	−62.9 (13)	O2—C7—C8—O1	−160.9 (16)
C7—O2—C3—C4	33 (3)	O2'—C7—C8—O1	164.1 (14)
C2—C3—C4—C5	−1.1 (4)	O2—C7—C8—N1	19.4 (17)
O2'—C3—C4—C5	−164.0 (13)	O2'—C7—C8—N1	−15.6 (15)
O2—C3—C4—C5	162.1 (14)	C8—N1—C9—C10	100.5 (3)
C2—C3—C4—N1	179.0 (2)	C4—N1—C9—C10	−77.4 (3)
O2'—C3—C4—N1	16.0 (14)	N1—C9—C10—C11	−25.9 (3)
O2—C3—C4—N1	−17.9 (14)	N1—C9—C10—C15	155.7 (2)
C8—N1—C4—C5	−177.8 (2)	C15—C10—C11—C12	−0.3 (4)
C9—N1—C4—C5	0.1 (3)	C9—C10—C11—C12	−178.7 (3)
C8—N1—C4—C3	2.1 (3)	C10—C11—C12—C13	0.6 (4)
C9—N1—C4—C3	−180.0 (2)	C11—C12—C13—C14	−0.8 (5)
C3—C4—C5—C6	0.8 (4)	C12—C13—C14—C15	0.7 (5)
N1—C4—C5—C6	−179.3 (2)	C11—C10—C15—C14	0.2 (4)
C2—C1—C6—C5	−0.5 (4)	C9—C10—C15—C14	178.6 (2)
Cl1—C1—C6—C5	−179.6 (2)	C13—C14—C15—C10	−0.4 (4)

Experimental details

Crystal data
Chemical formula	C₁₅H₁₂ClNO₂
M_r	273.71
Crystal system, space group	Monoclinic, P2₁/c
Temperature (K)	298
a, b, c (Å)	5.0894 (11), 12.630 (3), 20.070 (4)
β (°)	91.833 (4)
V (Å³)	1289.4 (5)
Z	4
Radiation type	Mo Kα
µ (mm⁻¹)	0.29
Crystal size (mm)	0.16 × 0.14 × 0.10

Data collection
Diffractometer	Bruker SMART CCD area-detector diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2005)
T_min, T_max	0.955, 0.971
No. of measured, independent and observed [I > 2σ(I)] reflections	6606, 2268, 1402
R_int	0.031
(sin θ/λ)_max (Å⁻¹)	0.596

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.044, 0.121, 1.02
No. of reflections	2268
No. of parameters	182
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.18, −0.21

Computer programs: SMART (Bruker 2005), SAINT (Bruker 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), XP in SHELXTL (Sheldrick, 2008).

Acknowledgements

This study was supported by the Key Program Projects of the Municipal Natural Science Foundation of Chongqing, China (grant No. CSTC,2007AC1042).

References

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