organic compounds
4,6-Dibromo-2,3-dimethylphenol
aSchool of Chemistry and Chemical Engineering, Pingdingshan University, Pingdingshan 467000, People's Republic of China, and bKey Laboratory of Pesticide and Chemical Biology of the Ministry of Education, College of Chemistry, Central China Normal University, Wuhan 430079, People's Republic of China
*Correspondence e-mail: qwjgq@163.com
The molecule of the title compound, C8H8Br2O, is approximately planar with a maximum deviation of 0.063 (1) Å for one of the Br atoms. In the crystal, adjacent molecules are joined intermolecular O—H⋯O hydrogen bonds, forming chains parallel to [010]. The structure also features a short Br⋯Br interaction of 3.362 (1) Å.
Related literature
For the synthesis, see: Lai et al. (1993). For a related structure, see: Bringmann & Messer (2001).
Experimental
Crystal data
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Data collection: SMART (Bruker, 1997); cell SAINT (Bruker, 1999); data reduction: SAINT; program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL.
Supporting information
10.1107/S1600536811003151/ng5106sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536811003151/ng5106Isup2.hkl
The title compound, synthesized by 2,3-dimethyl phenylamine through three steps such as bromination, diazotization-bromination-hydrolysis reaction.The operating process was based on the literarure (Lai et al., 1993) and made some improvement.
Firstly, 1-amino-4-bromo-2,3-dimethylbenzene was prepared from 2,3-dimethyl phenylamine as described in the literarure(Lai et al., 1993). Then treatment as follows: Sodiumnitrite (1.75 g, 25 mmol) in water (10 ml) was added dropwise into the rapidly stirring mixture of 40% hydrogen bromide (15 ml) containing l-amino-2,3-dimethylbenzene (5.00 g, 25 mmol). The mixture was kept in an ice-bath stiring for 2 h, while the temperature was kept below 5°C by the addition of pieces of ice. Then added 1.97 g (14 mmol) cuprous bromide which was pretreatmented by refluxing with 10 ml 40% hydrogen bromide solution for 1 h. After the addition the mixture was heated refluxing for an additional 1 h, and then cooled to room temperature, extract by methylenechloride. The organic layer was washed by water, dried by anhydrous natriumsulfate, evaporated under reduced pressure and chromatographed on silica gel with hexane as the
The title compound was obtained as needle crystal solid 1.82 grams. Yield was 26%. Colorless needle-like single crystals suitable for X-ray diffraction studies were obtained by slow evaporation of a solution of the title compound in chloroform: methanol (3: 1) at room temperature.In (I), all carbon H atoms were positioned geometrically and refined as riding atoms, with C—H = 0.93 Å and U\ĩso\~(H) = 1.2U\~eq\~(C) for aromatic H atoms, and C—H = 0.96 Å and U\ĩso\~(H) =1.5U\~eq\~(C) for methyl H atoms. H1 atom was found first from the difference map and placed at its ideal position with the O—H=0.82Å and U\ĩso\~(H)=1.5U\~eq\~(O). The Friedel pairs is 1275.
Data collection: SMART (Bruker, 1997); cell
SAINT (Bruker, 1999); data reduction: SAINT (Bruker, 1999); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).C8H8Br2O | F(000) = 268 |
Mr = 279.96 | Dx = 2.035 Mg m−3 |
Monoclinic, P21 | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: P 2yb | Cell parameters from 2355 reflections |
a = 7.3604 (5) Å | θ = 2.8–24.5° |
b = 4.4310 (6) Å | µ = 8.81 mm−1 |
c = 14.0245 (10) Å | T = 298 K |
β = 92.482 (1)° | Needle, colorless |
V = 456.96 (8) Å3 | 0.16 × 0.12 × 0.10 mm |
Z = 2 |
Bruker SMART CCD area-detector diffractometer | 2250 independent reflections |
Radiation source: fine-focus sealed tube | 1882 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.042 |
phi and ω scans | θmax = 28.3°, θmin = 2.8° |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | h = −9→9 |
Tmin = 0.333, Tmax = 0.473 | k = −5→5 |
5557 measured reflections | l = −18→18 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.037 | H-atom parameters constrained |
wR(F2) = 0.090 | w = 1/[σ2(Fo2) + (0.0403P)2] where P = (Fo2 + 2Fc2)/3 |
S = 0.99 | (Δ/σ)max = 0.001 |
2250 reflections | Δρmax = 0.57 e Å−3 |
102 parameters | Δρmin = −0.29 e Å−3 |
0 restraints | Absolute structure: Flack (1983), 1275 Friedel pairs |
Primary atom site location: structure-invariant direct methods | Absolute structure parameter: 0.02 (2) |
C8H8Br2O | V = 456.96 (8) Å3 |
Mr = 279.96 | Z = 2 |
Monoclinic, P21 | Mo Kα radiation |
a = 7.3604 (5) Å | µ = 8.81 mm−1 |
b = 4.4310 (6) Å | T = 298 K |
c = 14.0245 (10) Å | 0.16 × 0.12 × 0.10 mm |
β = 92.482 (1)° |
Bruker SMART CCD area-detector diffractometer | 2250 independent reflections |
Absorption correction: multi-scan (SADABS; Sheldrick, 1996) | 1882 reflections with I > 2σ(I) |
Tmin = 0.333, Tmax = 0.473 | Rint = 0.042 |
5557 measured reflections |
R[F2 > 2σ(F2)] = 0.037 | H-atom parameters constrained |
wR(F2) = 0.090 | Δρmax = 0.57 e Å−3 |
S = 0.99 | Δρmin = −0.29 e Å−3 |
2250 reflections | Absolute structure: Flack (1983), 1275 Friedel pairs |
102 parameters | Absolute structure parameter: 0.02 (2) |
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 | 0.87217 (5) | −0.34219 (12) | 0.92038 (3) | 0.05521 (15) | |
Br2 | 0.86105 (8) | 0.29262 (15) | 0.57447 (4) | 0.0790 (2) | |
C1 | 0.5729 (5) | 0.0139 (10) | 0.8491 (3) | 0.0436 (9) | |
C2 | 0.4789 (5) | 0.2000 (10) | 0.7846 (3) | 0.0458 (10) | |
C3 | 0.5600 (6) | 0.2866 (12) | 0.6995 (3) | 0.0496 (9) | |
C4 | 0.7350 (6) | 0.1753 (13) | 0.6843 (3) | 0.0516 (9) | |
C5 | 0.8255 (5) | −0.0114 (11) | 0.7471 (3) | 0.0498 (10) | |
H5 | 0.9405 | −0.0835 | 0.7342 | 0.060* | |
C6 | 0.7440 (5) | −0.0922 (9) | 0.8300 (3) | 0.0429 (9) | |
C7 | 0.2920 (6) | 0.3103 (13) | 0.8071 (4) | 0.0621 (12) | |
H7A | 0.2479 | 0.1971 | 0.8597 | 0.093* | |
H7B | 0.2110 | 0.2837 | 0.7522 | 0.093* | |
H7C | 0.2978 | 0.5204 | 0.8237 | 0.093* | |
C8 | 0.4589 (8) | 0.4836 (14) | 0.6281 (4) | 0.0684 (14) | |
H8A | 0.5442 | 0.5917 | 0.5911 | 0.103* | |
H8B | 0.3849 | 0.6245 | 0.6610 | 0.103* | |
H8C | 0.3828 | 0.3605 | 0.5866 | 0.103* | |
O1 | 0.4886 (4) | −0.0551 (8) | 0.9326 (2) | 0.0533 (8) | |
H1 | 0.5505 | −0.1777 | 0.9634 | 0.080* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0508 (2) | 0.0528 (2) | 0.0620 (3) | 0.0041 (2) | 0.00077 (17) | −0.0045 (2) |
Br2 | 0.0927 (4) | 0.0918 (4) | 0.0547 (3) | −0.0172 (3) | 0.0285 (3) | −0.0037 (3) |
C1 | 0.043 (2) | 0.0419 (19) | 0.046 (2) | −0.0093 (17) | 0.0072 (16) | −0.0128 (19) |
C2 | 0.047 (2) | 0.042 (3) | 0.049 (2) | −0.0074 (17) | 0.0016 (16) | −0.0067 (17) |
C3 | 0.061 (2) | 0.044 (2) | 0.043 (2) | −0.012 (2) | −0.0015 (18) | −0.007 (2) |
C4 | 0.059 (2) | 0.054 (2) | 0.043 (2) | −0.015 (2) | 0.0118 (16) | −0.004 (2) |
C5 | 0.045 (2) | 0.049 (2) | 0.056 (3) | −0.006 (2) | 0.0103 (18) | −0.014 (2) |
C6 | 0.043 (2) | 0.042 (2) | 0.043 (2) | −0.0011 (17) | −0.0010 (16) | −0.0099 (18) |
C7 | 0.046 (2) | 0.066 (3) | 0.074 (3) | 0.004 (2) | 0.007 (2) | 0.001 (3) |
C8 | 0.089 (4) | 0.063 (3) | 0.052 (3) | −0.001 (3) | −0.006 (3) | 0.002 (3) |
O1 | 0.0545 (17) | 0.0582 (19) | 0.0482 (18) | 0.0023 (15) | 0.0143 (13) | 0.0007 (15) |
Br1—C6 | 1.903 (4) | C5—C6 | 1.379 (6) |
Br2—C4 | 1.905 (4) | C5—H5 | 0.9300 |
C1—C6 | 1.381 (5) | C7—H7A | 0.9600 |
C1—O1 | 1.383 (5) | C7—H7B | 0.9600 |
C1—C2 | 1.387 (6) | C7—H7C | 0.9600 |
C2—C3 | 1.411 (6) | C8—H8A | 0.9600 |
C2—C7 | 1.507 (6) | C8—H8B | 0.9600 |
C3—C4 | 1.404 (7) | C8—H8C | 0.9600 |
C3—C8 | 1.501 (7) | O1—H1 | 0.8200 |
C4—C5 | 1.361 (7) | ||
C6—C1—O1 | 122.4 (4) | C5—C6—Br1 | 119.5 (3) |
C6—C1—C2 | 120.6 (4) | C1—C6—Br1 | 119.9 (3) |
O1—C1—C2 | 117.1 (3) | C2—C7—H7A | 109.5 |
C1—C2—C3 | 119.8 (4) | C2—C7—H7B | 109.5 |
C1—C2—C7 | 119.4 (4) | H7A—C7—H7B | 109.5 |
C3—C2—C7 | 120.9 (4) | C2—C7—H7C | 109.5 |
C4—C3—C2 | 117.2 (4) | H7A—C7—H7C | 109.5 |
C4—C3—C8 | 122.4 (4) | H7B—C7—H7C | 109.5 |
C2—C3—C8 | 120.4 (4) | C3—C8—H8A | 109.5 |
C5—C4—C3 | 122.8 (4) | C3—C8—H8B | 109.5 |
C5—C4—Br2 | 116.6 (3) | H8A—C8—H8B | 109.5 |
C3—C4—Br2 | 120.6 (4) | C3—C8—H8C | 109.5 |
C4—C5—C6 | 119.0 (4) | H8A—C8—H8C | 109.5 |
C4—C5—H5 | 120.5 | H8B—C8—H8C | 109.5 |
C6—C5—H5 | 120.5 | C1—O1—H1 | 109.5 |
C5—C6—C1 | 120.6 (4) | ||
C6—C1—C2—C3 | −1.2 (6) | C2—C3—C4—Br2 | −177.2 (3) |
O1—C1—C2—C3 | 178.0 (4) | C8—C3—C4—Br2 | 4.2 (7) |
C6—C1—C2—C7 | 179.6 (4) | C3—C4—C5—C6 | −1.1 (7) |
O1—C1—C2—C7 | −1.3 (6) | Br2—C4—C5—C6 | 177.0 (3) |
C1—C2—C3—C4 | 0.3 (6) | C4—C5—C6—C1 | 0.2 (6) |
C7—C2—C3—C4 | 179.6 (4) | C4—C5—C6—Br1 | −177.9 (3) |
C1—C2—C3—C8 | 178.9 (4) | O1—C1—C6—C5 | −178.2 (4) |
C7—C2—C3—C8 | −1.8 (7) | C2—C1—C6—C5 | 0.9 (6) |
C2—C3—C4—C5 | 0.8 (7) | O1—C1—C6—Br1 | −0.1 (5) |
C8—C3—C4—C5 | −177.8 (5) | C2—C1—C6—Br1 | 179.0 (3) |
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O1i | 0.82 | 2.25 | 2.913 (4) | 139 |
O1—H1···Br1 | 0.82 | 2.57 | 3.108 (3) | 124 |
C8—H8A···Br2 | 0.96 | 2.70 | 3.200 (6) | 113 |
Symmetry code: (i) −x+1, y−1/2, −z+2. |
Experimental details
Crystal data | |
Chemical formula | C8H8Br2O |
Mr | 279.96 |
Crystal system, space group | Monoclinic, P21 |
Temperature (K) | 298 |
a, b, c (Å) | 7.3604 (5), 4.4310 (6), 14.0245 (10) |
β (°) | 92.482 (1) |
V (Å3) | 456.96 (8) |
Z | 2 |
Radiation type | Mo Kα |
µ (mm−1) | 8.81 |
Crystal size (mm) | 0.16 × 0.12 × 0.10 |
Data collection | |
Diffractometer | Bruker SMART CCD area-detector diffractometer |
Absorption correction | Multi-scan (SADABS; Sheldrick, 1996) |
Tmin, Tmax | 0.333, 0.473 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5557, 2250, 1882 |
Rint | 0.042 |
(sin θ/λ)max (Å−1) | 0.667 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.037, 0.090, 0.99 |
No. of reflections | 2250 |
No. of parameters | 102 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.57, −0.29 |
Absolute structure | Flack (1983), 1275 Friedel pairs |
Absolute structure parameter | 0.02 (2) |
Computer programs: SMART (Bruker, 1997), SAINT (Bruker, 1999), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
O1—H1···O1i | 0.82 | 2.25 | 2.913 (4) | 138.7 |
Symmetry code: (i) −x+1, y−1/2, −z+2. |
Acknowledgements
This research was supported by the Top-class Foundation of Pingdingshan University (No. 2006045).
References
Bringmann, G. & Messer, K. (2001). Phytochemistry, 56, 387–391. Web of Science CSD CrossRef PubMed CAS Google Scholar
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In the title compound,C~8~H~8~Br~2Õ, the adjacent molecules are molecules are joined togethe by the O1—H1···O1 (-x, y - 1/2, 2 - z) hydrogen bond, forming a one-dimensional chain running parallel to the [010] direction(Table 1 and Figure 2). Also Br···Br interaction was observed in (I) with a distance of 3.362 (1) Å between them All the bond lengths and angles are similar to the reported compound (Bringmann et al., 2001).