Ethyl 3-(10-bromo-anthracen-9-yl)-5-methyl-1,2-oxazole-4-carboxyl-ate.

In the title compound, C21H16BrNO3, the mean planes of the anthracene tricycle and isoxazole ring are inclined to each other at a dihedral angle of 72.12 (7)°. The carb-oxy group is slightly out of the isoxazole mean plane, with a maximum deviation of 0.070 (5) Å for the carbonyl O atom. In the crystal, pairs of weak C-H⋯O hydrogen bonds link the mol-ecules into dimers, and weak C-H⋯N inter-actions further link these dimers into corrugated layers parallel to the bc plane.

Related literature

For the synthesis of anthryl isoxazoles, see: Mosher & Natale (1995 ▶); Zhou et al. (1997 ▶); Han & Natale (2001 ▶); Rider et al. (2010 ▶); Mirzaei et al. (2012 ▶). For related structures, see: Mosher et al. (1996 ▶); Han et al. (2002 ▶, 2003 ▶); Li et al. (2006 ▶, 2008 ▶). For the anti­tumor activity of aryl isoxazole amides (AIMs), see: Han et al. (2009 ▶); Gajewski et al. (2009 ▶); Balasubramanian et al. (2011 ▶); Neidle (2012 ▶); Kohn et al. (2012 ▶); Shoemaker (2006 ▶).

Experimental

Crystal data

C21H16BrNO3

M = 410.26

Monoclinic,

a = 8.8437 (1) Å

b = 16.7099 (2) Å

c = 11.7157 (2) Å

β = 92.419 (1)°

V = 1729.77 (4) Å3

Z = 4

Mo Kα radiation

μ = 2.40 mm−1

T = 100 K

0.49 × 0.47 × 0.38 mm

Data collection

Bruker SMART BREEZE CCD diffractometer

Absorption correction: multi-scan (SADABS; Bruker, 2008 ▶) T min = 0.39, T max = 0.47

34958 measured reflections

4290 independent reflections

4128 reflections with I > 2σ(I)

R int = 0.020

Refinement

R[F 2 > 2σ(F 2)] = 0.025

wR(F 2) = 0.074

S = 1.05

4290 reflections

237 parameters

H-atom parameters constrained

Δρmax = 0.51 e Å−3

Δρmin = −0.39 e Å−3

Data collection: APEX2 (Bruker, 2008 ▶); cell refinement: SAINT (Bruker, 2008 ▶); data reduction: SAINT; program(s) used to solve structure: SHELXL97 (Sheldrick, 2008 ▶); program(s) used to refine structure: SHELXS97 (Sheldrick, 2008 ▶); molecular graphics: OLEX2 (Dolomanov et al., 2009 ▶); software used to prepare material for publication: OLEX2 and publCIF (Westrip, 2010 ▶).

Crystal structure: contains datablock(s) I. DOI: 10.1107/S1600536813031395/cv5433sup1.cif

Structure factors: contains datablock(s) I. DOI: 10.1107/S1600536813031395/cv5433Isup2.hkl

Click here for additional data file.

Supplementary material file. DOI: 10.1107/S1600536813031395/cv5433Isup3.cml

Additional supplementary materials: crystallographic information; 3D view; checkCIF report

C21H16BrNO3	F(000) = 832
Mr = 410.26	Dx = 1.575 Mg m−3
Monoclinic, P21/c	Mo Kα radiation, λ = 0.71073 Å
a = 8.8437 (1) Å	Cell parameters from 330 reflections
b = 16.7099 (2) Å	θ = 0.3–27.5°
c = 11.7157 (2) Å	µ = 2.40 mm−1
β = 92.419 (1)°	T = 100 K
V = 1729.77 (4) Å3	Prism, translucent yellow
Z = 4	0.49 × 0.47 × 0.38 mm

Bruker SMART BREEZE CCD diffractometer	4128 reflections with I > 2σ(I)
Radiation source: 2 kW sealed X-ray tube	Rint = 0.020
π and ω scans	θmax = 28.3°, θmin = 2.1°
Absorption correction: multi-scan (SADABS; Bruker, 2008)	h = −11→11
Tmin = 0.39, Tmax = 0.47	k = −22→22
34958 measured reflections	l = −15→14
4290 independent reflections

Refinement on F2	Primary atom site location: structure-invariant direct methods
Least-squares matrix: full	Hydrogen site location: inferred from neighbouring sites
R[F2 > 2σ(F2)] = 0.025	H-atom parameters constrained
wR(F2) = 0.074	w = 1/[σ2(Fo2) + (0.0448P)2 + 1.2294P] where P = (Fo2 + 2Fc2)/3
S = 1.05	(Δ/σ)max = 0.002
4290 reflections	Δρmax = 0.51 e Å−3
237 parameters	Δρmin = −0.39 e Å−3
0 restraints

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.

	x	y	z	Uiso*/Ueq
Br1	0.65922 (2)	0.19002 (2)	0.12783 (2)	0.02178 (7)
O1	0.29601 (12)	0.46676 (6)	0.02087 (8)	0.0145 (2)
O2	0.14962 (15)	0.57548 (8)	−0.00887 (10)	0.0261 (3)
O3	0.06569 (12)	0.53843 (6)	0.34089 (9)	0.0145 (2)
N1	0.15853 (14)	0.46963 (7)	0.35626 (10)	0.0142 (2)
C1	0.31314 (18)	0.19895 (9)	0.06508 (13)	0.0166 (3)
H1	0.3800	0.1580	0.0424	0.020*
C2	0.16567 (19)	0.19731 (9)	0.02681 (13)	0.0187 (3)
H2	0.1310	0.1554	−0.0224	0.022*
C3	0.06357 (17)	0.25744 (9)	0.05964 (12)	0.0167 (3)
H3	−0.0390	0.2555	0.0323	0.020*
C4	0.11134 (17)	0.31807 (8)	0.13019 (12)	0.0135 (3)
H4	0.0412	0.3577	0.1520	0.016*
C5	0.52484 (16)	0.45590 (8)	0.35132 (12)	0.0141 (3)
H5	0.4571	0.4969	0.3725	0.017*
C6	0.67305 (17)	0.45991 (9)	0.38810 (12)	0.0171 (3)
H6	0.7075	0.5034	0.4345	0.020*
C7	0.77617 (17)	0.39918 (10)	0.35718 (13)	0.0191 (3)
H7	0.8791	0.4022	0.3834	0.023*
C8	0.72856 (16)	0.33668 (9)	0.29027 (13)	0.0175 (3)
H8	0.7993	0.2969	0.2701	0.021*
C9	0.52055 (16)	0.26791 (8)	0.17830 (12)	0.0133 (2)
C10	0.31823 (15)	0.38718 (8)	0.23963 (11)	0.0111 (2)
C11	0.46912 (15)	0.39100 (8)	0.28134 (11)	0.0116 (2)
C12	0.57441 (16)	0.32977 (8)	0.24980 (12)	0.0132 (3)
C13	0.36915 (16)	0.26146 (8)	0.13894 (11)	0.0126 (2)
C14	0.26560 (16)	0.32284 (8)	0.17184 (11)	0.0114 (2)
C15	0.21490 (15)	0.45584 (8)	0.25655 (11)	0.0111 (2)
C16	0.16273 (15)	0.51365 (8)	0.17353 (11)	0.0118 (2)
C17	0.06993 (15)	0.56274 (8)	0.23177 (12)	0.0128 (2)
C18	−0.02091 (17)	0.63431 (9)	0.19866 (13)	0.0184 (3)
H18A	−0.1080	0.6384	0.2474	0.028*
H18B	−0.0567	0.6295	0.1186	0.028*
H18C	0.0419	0.6824	0.2081	0.028*
C19	0.19946 (16)	0.52302 (8)	0.05278 (12)	0.0139 (3)
C20	0.34574 (17)	0.47134 (9)	−0.09567 (12)	0.0162 (3)
H20A	0.4147	0.5174	−0.1044	0.019*
H20B	0.2578	0.4778	−0.1500	0.019*
C21	0.42720 (19)	0.39376 (10)	−0.11786 (13)	0.0211 (3)
H21A	0.4647	0.3944	−0.1954	0.032*
H21B	0.3571	0.3488	−0.1102	0.032*
H21C	0.5126	0.3878	−0.0624	0.032*

	U11	U22	U33	U12	U13	U23
Br1	0.01713 (9)	0.01729 (9)	0.03139 (10)	0.00372 (5)	0.00673 (6)	−0.00296 (5)
O1	0.0174 (5)	0.0153 (5)	0.0111 (4)	0.0030 (4)	0.0040 (4)	0.0021 (4)
O2	0.0333 (7)	0.0279 (6)	0.0175 (5)	0.0158 (5)	0.0050 (5)	0.0084 (4)
O3	0.0153 (5)	0.0136 (5)	0.0146 (5)	0.0031 (4)	0.0024 (4)	−0.0010 (4)
N1	0.0152 (6)	0.0125 (5)	0.0150 (5)	0.0029 (4)	0.0015 (4)	0.0002 (4)
C1	0.0210 (7)	0.0129 (6)	0.0162 (6)	−0.0005 (5)	0.0036 (5)	−0.0019 (5)
C2	0.0237 (8)	0.0157 (7)	0.0167 (7)	−0.0045 (5)	0.0010 (6)	−0.0026 (5)
C3	0.0169 (7)	0.0167 (6)	0.0162 (6)	−0.0039 (5)	−0.0020 (5)	0.0016 (5)
C4	0.0143 (7)	0.0125 (6)	0.0135 (6)	0.0005 (5)	0.0004 (5)	0.0020 (5)
C5	0.0157 (6)	0.0142 (6)	0.0124 (6)	0.0002 (5)	0.0003 (5)	0.0002 (5)
C6	0.0177 (7)	0.0183 (7)	0.0150 (6)	−0.0038 (5)	−0.0016 (5)	−0.0002 (5)
C7	0.0128 (6)	0.0222 (7)	0.0219 (7)	−0.0011 (5)	−0.0023 (5)	0.0041 (6)
C8	0.0121 (6)	0.0175 (7)	0.0227 (7)	0.0020 (5)	0.0006 (5)	0.0028 (5)
C9	0.0131 (6)	0.0108 (6)	0.0162 (6)	0.0029 (5)	0.0042 (5)	0.0010 (5)
C10	0.0123 (6)	0.0110 (6)	0.0101 (5)	0.0013 (5)	0.0013 (4)	0.0018 (4)
C11	0.0126 (6)	0.0115 (6)	0.0106 (6)	0.0000 (5)	0.0012 (4)	0.0019 (4)
C12	0.0124 (6)	0.0128 (6)	0.0143 (6)	0.0008 (5)	0.0015 (5)	0.0033 (5)
C13	0.0147 (6)	0.0107 (6)	0.0126 (6)	0.0001 (5)	0.0024 (5)	0.0014 (5)
C14	0.0125 (6)	0.0111 (5)	0.0107 (6)	−0.0004 (5)	0.0013 (5)	0.0021 (5)
C15	0.0108 (6)	0.0104 (6)	0.0122 (6)	−0.0010 (5)	−0.0003 (4)	−0.0007 (4)
C16	0.0114 (6)	0.0111 (6)	0.0129 (6)	0.0004 (5)	−0.0005 (4)	0.0004 (5)
C17	0.0121 (6)	0.0120 (6)	0.0144 (6)	−0.0012 (5)	−0.0008 (5)	−0.0009 (5)
C18	0.0179 (7)	0.0135 (6)	0.0235 (7)	0.0043 (5)	−0.0016 (5)	−0.0019 (5)
C19	0.0132 (6)	0.0145 (6)	0.0139 (6)	0.0001 (5)	0.0006 (5)	−0.0001 (5)
C20	0.0207 (7)	0.0175 (7)	0.0106 (6)	−0.0008 (5)	0.0049 (5)	0.0010 (5)
C21	0.0246 (8)	0.0213 (7)	0.0180 (7)	0.0028 (6)	0.0063 (6)	−0.0027 (6)

Br1—C9	1.8996 (13)	C8—H8	0.9500
O1—C19	1.3340 (17)	C8—C12	1.4290 (19)
O1—C20	1.4539 (16)	C9—C12	1.4013 (19)
O2—C19	1.2073 (18)	C9—C13	1.4017 (19)
O3—N1	1.4197 (15)	C10—C11	1.4031 (18)
O3—C17	1.3435 (17)	C10—C14	1.4043 (19)
N1—C15	1.3097 (18)	C10—C15	1.4853 (18)
C1—H1	0.9500	C11—C12	1.4420 (19)
C1—C2	1.361 (2)	C13—C14	1.4384 (19)
C1—C13	1.4314 (19)	C15—C16	1.4332 (18)
C2—H2	0.9500	C16—C17	1.3636 (19)
C2—C3	1.415 (2)	C16—C19	1.4731 (18)
C3—H3	0.9500	C17—C18	1.4832 (19)
C3—C4	1.363 (2)	C18—H18A	0.9800
C4—H4	0.9500	C18—H18B	0.9800
C4—C14	1.4316 (19)	C18—H18C	0.9800
C5—H5	0.9500	C20—H20A	0.9900
C5—C6	1.364 (2)	C20—H20B	0.9900
C5—C11	1.4342 (19)	C20—C21	1.511 (2)
C6—H6	0.9500	C21—H21A	0.9800
C6—C7	1.422 (2)	C21—H21B	0.9800
C7—H7	0.9500	C21—H21C	0.9800
C7—C8	1.362 (2)
C19—O1—C20	116.66 (11)	C9—C12—C11	118.01 (12)
C17—O3—N1	109.05 (10)	C1—C13—C14	118.32 (13)
C15—N1—O3	105.62 (11)	C9—C13—C1	123.80 (13)
C2—C1—H1	119.5	C9—C13—C14	117.85 (12)
C2—C1—C13	121.07 (14)	C4—C14—C13	118.50 (12)
C13—C1—H1	119.5	C10—C14—C4	121.59 (13)
C1—C2—H2	119.7	C10—C14—C13	119.86 (13)
C1—C2—C3	120.64 (13)	N1—C15—C10	120.96 (12)
C3—C2—H2	119.7	N1—C15—C16	111.28 (12)
C2—C3—H3	119.8	C16—C15—C10	127.76 (12)
C4—C3—C2	120.50 (14)	C15—C16—C19	130.21 (12)
C4—C3—H3	119.8	C17—C16—C15	104.43 (12)
C3—C4—H4	119.5	C17—C16—C19	125.33 (12)
C3—C4—C14	120.97 (13)	O3—C17—C16	109.62 (12)
C14—C4—H4	119.5	O3—C17—C18	117.14 (12)
C6—C5—H5	119.3	C16—C17—C18	133.24 (13)
C6—C5—C11	121.34 (13)	C17—C18—H18A	109.5
C11—C5—H5	119.3	C17—C18—H18B	109.5
C5—C6—H6	119.9	C17—C18—H18C	109.5
C5—C6—C7	120.18 (14)	H18A—C18—H18B	109.5
C7—C6—H6	119.9	H18A—C18—H18C	109.5
C6—C7—H7	119.7	H18B—C18—H18C	109.5
C8—C7—C6	120.54 (13)	O1—C19—C16	111.34 (12)
C8—C7—H7	119.7	O2—C19—O1	124.46 (13)
C7—C8—H8	119.3	O2—C19—C16	124.19 (13)
C7—C8—C12	121.36 (14)	O1—C20—H20A	110.5
C12—C8—H8	119.3	O1—C20—H20B	110.5
C12—C9—Br1	118.94 (10)	O1—C20—C21	106.36 (11)
C12—C9—C13	123.32 (12)	H20A—C20—H20B	108.6
C13—C9—Br1	117.72 (10)	C21—C20—H20A	110.5
C11—C10—C14	121.29 (12)	C21—C20—H20B	110.5
C11—C10—C15	120.00 (12)	C20—C21—H21A	109.5
C14—C10—C15	118.41 (12)	C20—C21—H21B	109.5
C5—C11—C12	118.23 (12)	C20—C21—H21C	109.5
C10—C11—C5	122.15 (12)	H21A—C21—H21B	109.5
C10—C11—C12	119.57 (12)	H21A—C21—H21C	109.5
C8—C12—C11	118.36 (13)	H21B—C21—H21C	109.5
C9—C12—C8	123.60 (13)
Br1—C9—C12—C8	−1.87 (19)	C10—C15—C16—C19	−2.4 (2)
Br1—C9—C12—C11	176.22 (10)	C11—C5—C6—C7	0.1 (2)
Br1—C9—C13—C1	1.24 (19)	C11—C10—C14—C4	179.20 (12)
Br1—C9—C13—C14	−176.59 (9)	C11—C10—C14—C13	−3.33 (19)
O3—N1—C15—C10	−179.64 (11)	C11—C10—C15—N1	−75.68 (17)
O3—N1—C15—C16	0.03 (15)	C11—C10—C15—C16	104.71 (16)
N1—O3—C17—C16	−0.55 (15)	C12—C9—C13—C1	179.42 (13)
N1—O3—C17—C18	179.89 (11)	C12—C9—C13—C14	1.6 (2)
N1—C15—C16—C17	−0.35 (16)	C13—C1—C2—C3	−0.3 (2)
N1—C15—C16—C19	178.00 (13)	C13—C9—C12—C8	179.97 (13)
C1—C2—C3—C4	0.0 (2)	C13—C9—C12—C11	−1.9 (2)
C1—C13—C14—C4	0.65 (19)	C14—C10—C11—C5	−179.58 (12)
C1—C13—C14—C10	−176.89 (12)	C14—C10—C11—C12	2.97 (19)
C2—C1—C13—C9	−177.91 (14)	C14—C10—C15—N1	110.56 (15)
C2—C1—C13—C14	−0.1 (2)	C14—C10—C15—C16	−69.05 (18)
C2—C3—C4—C14	0.6 (2)	C15—C10—C11—C5	6.85 (19)
C3—C4—C14—C10	176.60 (13)	C15—C10—C11—C12	−170.60 (12)
C3—C4—C14—C13	−0.9 (2)	C15—C10—C14—C4	−7.13 (19)
C5—C6—C7—C8	0.3 (2)	C15—C10—C14—C13	170.34 (12)
C5—C11—C12—C8	0.29 (19)	C15—C16—C17—O3	0.54 (15)
C5—C11—C12—C9	−177.91 (12)	C15—C16—C17—C18	−179.99 (15)
C6—C5—C11—C10	−177.89 (13)	C15—C16—C19—O1	0.5 (2)
C6—C5—C11—C12	−0.4 (2)	C15—C16—C19—O2	−178.75 (15)
C6—C7—C8—C12	−0.4 (2)	C17—O3—N1—C15	0.32 (14)
C7—C8—C12—C9	178.20 (14)	C17—C16—C19—O1	178.55 (13)
C7—C8—C12—C11	0.1 (2)	C17—C16—C19—O2	−0.7 (2)
C9—C13—C14—C4	178.60 (12)	C19—O1—C20—C21	−169.06 (12)
C9—C13—C14—C10	1.06 (19)	C19—C16—C17—O3	−177.91 (12)
C10—C11—C12—C8	177.84 (12)	C19—C16—C17—C18	1.6 (2)
C10—C11—C12—C9	−0.36 (19)	C20—O1—C19—O2	1.5 (2)
C10—C15—C16—C17	179.29 (13)	C20—O1—C19—C16	−177.73 (11)

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···N1i	0.95	2.54	3.4305 (19)	155
C4—H4···O2ii	0.95	2.58	3.1990 (18)	123

Table 1

Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C2—H2⋯N1i	0.95	2.54	3.4305 (19)	155
C4—H4⋯O2ii	0.95	2.58	3.1990 (18)	123

Symmetry codes: (i) ; (ii) .