Crystal structure of 1,2-bis­(6-bromo-3,4-dihydro-2H-benz[e][1,3]oxazin-3-yl)ethane: a bromine-containing bis-benzoxazine

The solid-state structure of a 4-bromo­benzoxazine has been determined. The whole mol­ecule of the title compound is generated by inversion symmetry. This is a potential benzoxazine monomer for the preparation of phenolic materials.

Key indicators

• Single-crystal X-ray study
• T = 173 K
• Mean [sigma](C-C) = 0.007 Å
• R factor = 0.056
• wR factor = 0.143
• Data-to-parameter ratio = 14.4

checkCIF/PLATON results

No syntax errors found



Alert level C
PLAT341_ALERT_3_C Low Bond Precision on  C-C Bonds ...............    0.00675 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H5B    ..  BR1     ..       3.04 Ang.
PLAT480_ALERT_4_C Long H...A H-Bond Reported H2B    ..  O1      ..       2.64 Ang.
PLAT906_ALERT_3_C Large K value in the Analysis of Variance ......      2.929 Check
PLAT911_ALERT_3_C Missing # FCF Refl Between THmin & STh/L=  0.600          2 Report
PLAT972_ALERT_2_C Check Calcd Residual Density  0.91A From     Br1      -1.86 eA-3
PLAT972_ALERT_2_C Check Calcd Residual Density  1.06A From     Br1      -1.70 eA-3
PLAT976_ALERT_2_C Check Calcd Residual Density  1.05A From      O1      -0.41 eA-3
PLAT977_ALERT_2_C Check the Negative Difference Density on      H6      -0.31 eA-3

Alert level G
PLAT128_ALERT_4_G Alternate Setting for Input Space Group     C2/c       I2/a Note
PLAT910_ALERT_3_G Missing # of FCF Reflection(s) Below Theta(Min)           3 Note
PLAT912_ALERT_4_G Missing # of FCF Reflections Above STh/L=  0.600          8 Note
PLAT978_ALERT_2_G Number C-C Bonds with Positive Residual Density           4 Note

   0 ALERT level A = Most likely a serious problem - resolve or explain
   0 ALERT level B = A potentially serious problem, consider carefully
   9 ALERT level C = Check. Ensure it is not caused by an omission or oversight
   4 ALERT level G = General information/check it is not something unexpected

   0 ALERT type 1 CIF construction/syntax error, inconsistent or missing data
   5 ALERT type 2 Indicator that the structure model may be wrong or deficient
   4 ALERT type 3 Indicator that the structure quality may be low
   4 ALERT type 4 Improvement, methodology, query or suggestion
   0 ALERT type 5 Informative message, check

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Computing details

Data collection: X-AREA (Stoe & Cie, 2001); cell refinement: X-AREA (Stoe & Cie, 2001); data reduction: X-AREA (Stoe & Cie, 2001); program(s) used to solve structure: SHELXS (Sheldrick, 2008); program(s) used to refine structure: SHELXL-2014/7 (Sheldrick, 2015); molecular graphics: XP in SHELXTL-Plus (Sheldrick, 2008); software used to prepare material for publication: SHELXL-2014/7 (Sheldrick, 2015).

1,2-Bis(6-bromo-3,4-dihydro-2H-benz[e][1,3]oxazin-3-yl)ethane

Crystal data

C18H18Br2N2O2	F(000) = 904
Mr = 454.16	Dx = 1.777 Mg m^−3
Monoclinic, C2/c	Mo Kα radiation, λ = 0.71073 Å
a = 19.464 (2) Å	Cell parameters from 3703 reflections
b = 5.9444 (7) Å	θ = 3.6–26.0°
c = 17.2225 (19) Å	µ = 4.79 mm^−1
β = 121.557 (7)°	T = 173 K
V = 1698.0 (3) Å^3	Block, colourless
Z = 4	0.27 × 0.26 × 0.26 mm

Data collection

STOE IPDS II two-circle diffractometer	1391 reflections with I > 2σ(I)
Radiation source: Genix 3D IµS microfocus X-ray source	Rint = 0.078
ω scans	θmax = 25.6°, θmin = 3.6°
Absorption correction: multi-scan (X-Area; Stoe & Cie, 2001)	h = −20→23
Tmin = 0.905, Tmax = 1.000	k = −7→7
3703 measured reflections	l = −20→20
1583 independent reflections

Refinement

Refinement on F^2	Hydrogen site location: inferred from neighbouring sites
Least-squares matrix: full	H-atom parameters constrained
R[F^2 > 2σ(F^2)] = 0.056	w = 1/[σ^2(Fo^2) + (0.099P)^2] where P = (Fo^2 + 2Fc^2)/3
wR(F^2) = 0.143	(Δ/σ)max < 0.001
S = 1.07	Δρmax = 1.40 e Å^−3
1583 reflections	Δρmin = −1.92 e Å^−3
110 parameters	Extinction correction: SHELXL-2014/7 (Sheldrick 2015), Fc^*=kFc[1+0.001xFc^2λ^3/sin(2θ)]^-1/4
0 restraints	Extinction coefficient: 0.0037 (8)

Special details

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 (Ų)

	x	y	z	Uiso*/Ueq
Br1	0.60406 (3)	−0.02845 (9)	0.93353 (3)	0.0226 (3)
O1	0.67962 (18)	0.6369 (6)	0.7231 (2)	0.0176 (7)
N1	0.6072 (2)	0.4166 (7)	0.5842 (2)	0.0130 (8)
C1	0.5323 (2)	0.5473 (7)	0.5467 (3)	0.0141 (10)
H1A	0.5430	0.7067	0.5401	0.017*
H1B	0.5124	0.5406	0.5891	0.017*
C2	0.6783 (3)	0.5494 (8)	0.6434 (3)	0.0155 (10)
H2A	0.6811	0.6770	0.6082	0.019*
H2B	0.7268	0.4552	0.6639	0.019*
C3	0.6620 (3)	0.4788 (8)	0.7681 (3)	0.0141 (9)
C4	0.6259 (2)	0.2721 (8)	0.7288 (3)	0.0142 (9)
C5	0.6091 (2)	0.2158 (8)	0.6343 (3)	0.0140 (9)
H5A	0.6513	0.1123	0.6400	0.017*
H5B	0.5566	0.1372	0.5995	0.017*
C6	0.6083 (2)	0.1218 (8)	0.7781 (3)	0.0147 (9)
H6	0.5841	−0.0193	0.7526	0.018*
C7	0.6265 (3)	0.1804 (8)	0.8655 (3)	0.0164 (9)
C8	0.6619 (3)	0.3870 (9)	0.9044 (3)	0.0223 (10)
H8	0.6741	0.4248	0.9639	0.027*
C9	0.6787 (3)	0.5348 (8)	0.8552 (3)	0.0192 (11)
H9	0.7021	0.6768	0.8807	0.023*

Atomic displacement parameters (Ų)

	U^11	U^22	U^33	U^12	U^13	U^23
Br1	0.0261 (4)	0.0229 (4)	0.0255 (4)	0.00128 (17)	0.0181 (3)	0.00527 (19)
O1	0.0161 (15)	0.0160 (18)	0.0166 (15)	−0.0043 (12)	0.0058 (13)	−0.0018 (13)
N1	0.0078 (16)	0.0135 (19)	0.0148 (17)	0.0005 (13)	0.0039 (14)	0.0003 (15)
C1	0.010 (2)	0.013 (2)	0.014 (2)	0.0037 (16)	0.0029 (19)	−0.0009 (18)
C2	0.012 (2)	0.016 (2)	0.019 (2)	−0.0051 (16)	0.0081 (18)	−0.0034 (18)
C3	0.0114 (19)	0.014 (2)	0.014 (2)	0.0000 (15)	0.0047 (17)	0.0021 (17)
C4	0.0093 (18)	0.015 (2)	0.014 (2)	0.0023 (16)	0.0030 (15)	0.0016 (17)
C5	0.0105 (19)	0.012 (2)	0.016 (2)	0.0009 (15)	0.0039 (16)	−0.0021 (17)
C6	0.0098 (18)	0.015 (2)	0.018 (2)	0.0015 (15)	0.0062 (16)	0.0022 (18)
C7	0.020 (2)	0.014 (2)	0.020 (2)	0.0032 (16)	0.0137 (18)	0.0057 (18)
C8	0.028 (2)	0.023 (3)	0.017 (2)	−0.001 (2)	0.0126 (19)	−0.0036 (19)
C9	0.023 (2)	0.015 (2)	0.019 (2)	−0.0003 (17)	0.011 (2)	−0.0020 (18)

Geometric parameters (Å, º)

Br1—C7	1.909 (5)	C3—C4	1.402 (6)
O1—C3	1.372 (6)	C4—C6	1.393 (7)
O1—C2	1.455 (6)	C4—C5	1.519 (6)
N1—C2	1.450 (5)	C5—H5A	0.9900
N1—C5	1.462 (6)	C5—H5B	0.9900
N1—C1	1.470 (5)	C6—C7	1.397 (7)
C1—C1^i	1.538 (8)	C6—H6	0.9500
C1—H1A	0.9900	C7—C8	1.396 (7)
C1—H1B	0.9900	C8—C9	1.373 (8)
C2—H2A	0.9900	C8—H8	0.9500
C2—H2B	0.9900	C9—H9	0.9500
C3—C9	1.398 (7)
C3—O1—C2	113.7 (4)	C6—C4—C5	121.9 (4)
C2—N1—C5	108.0 (3)	C3—C4—C5	118.9 (4)
C2—N1—C1	112.6 (4)	N1—C5—C4	112.2 (4)
C5—N1—C1	113.8 (3)	N1—C5—H5A	109.2
N1—C1—C1^i	110.2 (4)	C4—C5—H5A	109.2
N1—C1—H1A	109.6	N1—C5—H5B	109.2
C1^i—C1—H1A	109.6	C4—C5—H5B	109.2
N1—C1—H1B	109.6	H5A—C5—H5B	107.9
C1^i—C1—H1B	109.6	C4—C6—C7	119.5 (4)
H1A—C1—H1B	108.1	C4—C6—H6	120.3
N1—C2—O1	113.4 (4)	C7—C6—H6	120.3
N1—C2—H2A	108.9	C8—C7—C6	121.3 (4)
O1—C2—H2A	108.9	C8—C7—Br1	119.4 (4)
N1—C2—H2B	108.9	C6—C7—Br1	119.2 (4)
O1—C2—H2B	108.9	C9—C8—C7	118.9 (4)
H2A—C2—H2B	107.7	C9—C8—H8	120.5
O1—C3—C9	117.2 (4)	C7—C8—H8	120.5
O1—C3—C4	122.5 (4)	C8—C9—C3	120.8 (5)
C9—C3—C4	120.3 (5)	C8—C9—H9	119.6
C6—C4—C3	119.2 (4)	C3—C9—H9	119.6
C2—N1—C1—C1^i	151.1 (5)	C1—N1—C5—C4	−77.1 (4)
C5—N1—C1—C1^i	−85.6 (6)	C6—C4—C5—N1	161.5 (4)
C5—N1—C2—O1	−64.9 (5)	C3—C4—C5—N1	−20.1 (5)
C1—N1—C2—O1	61.6 (5)	C3—C4—C6—C7	0.3 (6)
C3—O1—C2—N1	47.8 (5)	C5—C4—C6—C7	178.7 (4)
C2—O1—C3—C9	166.5 (4)	C4—C6—C7—C8	0.1 (7)
C2—O1—C3—C4	−15.8 (5)	C4—C6—C7—Br1	−178.8 (3)
O1—C3—C4—C6	−178.7 (4)	C6—C7—C8—C9	0.2 (7)
C9—C3—C4—C6	−1.1 (6)	Br1—C7—C8—C9	179.2 (4)
O1—C3—C4—C5	2.9 (6)	C7—C8—C9—C3	−1.0 (7)
C9—C3—C4—C5	−179.5 (4)	O1—C3—C9—C8	179.2 (4)
C2—N1—C5—C4	48.7 (5)	C4—C3—C9—C8	1.4 (7)

Symmetry code: (i) −x+1, −y+1, −z+1.

Hydrogen-bond geometry (Å, º)

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5B···Br1^ii	0.99	3.04	3.951 (5)	154
C2—H2B···O1^iii	0.99	2.64	3.506 (6)	146

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