organic compounds\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

2-Bromo-4,4-di­methyl-1-(2,4,5-tri­meth­oxy­phen­yl)pentan-3-one

aCollege of Chemistry and Chemical Engineering, Hunan University, Changsha 410082, People's Republic of China
*Correspondence e-mail: axhu0731@yahoo.com.cn

(Received 14 May 2009; accepted 17 May 2009; online 23 May 2009)

The three meth­oxy groups of the title compound, C16H23BrO4, are almost coplanar with the attached aromatic ring, forming dihedral angles of 7.19 (13), 2.48 (13) and 7.24 (12)°. The crystal structure shows an intra­molecular and an inter­molecular C—H⋯O inter­action.

Related literature

For background and related structures, see: Xu et al. (2007[Xu, J.-J., Hu, A.-X. & Cao, G. (2007). Acta Cryst. E63, o533-o534.]); Hu et al. (2007[Hu, A.-X., Cao, G., Xu, J.-J., Xia, L. & He, D.-H. (2007). J. Hunan Univ. (Nat. Sci.), 34, 78-81.]).

[Scheme 1]

Experimental

Crystal data
  • C16H23BrO4

  • Mr = 359.25

  • Triclinic, [P \overline 1]

  • a = 9.0173 (5) Å

  • b = 9.2086 (5) Å

  • c = 11.4217 (6) Å

  • α = 106.752 (1)°

  • β = 106.196 (1)°

  • γ = 100.353 (1)°

  • V = 836.51 (8) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 2.47 mm−1

  • T = 173 K

  • 0.47 × 0.40 × 0.21 mm

Data collection
  • Bruker SMART 1000 CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2004[Bruker (2004). SADABS Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.370, Tmax = 0.594

  • 6537 measured reflections

  • 3237 independent reflections

  • 2940 reflections with I > 2σ(I)

  • Rint = 0.017

Refinement
  • R[F2 > 2σ(F2)] = 0.025

  • wR(F2) = 0.073

  • S = 1.08

  • 3237 reflections

  • 196 parameters

  • H-atom parameters constrained

  • Δρmax = 0.65 e Å−3

  • Δρmin = −0.21 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
C2—H2⋯O4 1.00 2.50 3.089 (2) 117
C16—H16B⋯O2i 0.98 2.57 3.465 (3) 151
Symmetry code: (i) x, y+1, z.

Data collection: SMART (Bruker, 2001[Bruker (2001). SMART. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT-Plus (Bruker, 2003[Bruker (2003). SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

α-Bromoketone are well known for its universal applications in medical industry and play a key role in the synthesis of thiazole derivatives (Xu et al., 2007, Hu et al., 2007). It is found that α-bromoketones work as perfect intermediates and increase the efficiency. Herein we report the synthesis and structure of 2-bromo-4,4-dimethyl-1-(2,4,5-trimethyphenyl)- pentan-3-one.

Related literature top

For background and related structures, see: Xu et al. (2007); Hu et al. (2007).

Experimental top

To the compound of 4,4-dimethyl-1-(2,4,5-trimethyphenyl)pentan-3-one (0.02 mol), 1-butyl-3-methylimidazolidine bromide (0.02 mol) was slowly added. The reaction mixture was stirred for 30 min, then it was extracted with ethyl acetate (30 ml×3). The organic layers were collected, washed with water (20 ml), dried with anhydrous Na2SO4 and concentrated to give the desired product. Yield: 90.5%. m.p. 366~369 K. 1H NMR (CDCl3, 600 MHz) δ: 1.01 (s, 9H, 3×CH3), 3.20~3.28 (m, 2H, CH2), 3.80 (s, 3H, OCH3), 3.85 (s, 3H, OCH3), 3.87 (s, 3H, OCH3), 4.92~4.96 (m, 1H, CHBr), 6.49 (d, J = 4.2 Hz, 1H, C6H2 3-H), 6.61 (d, J = 6.0 Hz, 1H, C6H2 6-H).

Crystals suitable for X-ray structure determination were obtained by slow evaporation of an ethanol solution at room temperature.

Refinement top

The H-atoms were positioned geometrically, with C—H = 0.95 Å for aromatic, C—H = 0.98 Å for methyl, C—H = 0.99 Å for methylene and were refined as riding with Uiso(H) = 1.2 or 1.5 Ueq(Cmethyl).

Computing details top

Data collection: SMART (Bruker, 2001); cell refinement: SAINT-Plus (Bruker, 2003); data reduction: SAINT-Plus (Bruker, 2003); program(s) used to solve structure: SHELXTL (Sheldrick, 2008); program(s) used to refine structure: SHELXTL (Sheldrick, 2008); molecular graphics: SHELXTL (Sheldrick, 2008); software used to prepare material for publication: SHELXTL (Sheldrick, 2008).

Figures top
[Figure 1] Fig. 1. Molecular structure showing 30% probability displacement ellipsoids.
[Figure 2] Fig. 2. A packing diagram for the title compound. H atoms bonded to C atoms have been omitted for clarity.
2-Bromo-4,4-dimethyl-1-(2,4,5-trimethoxyphenyl)pentan-3-one top
Crystal data top
C16H23BrO4Z = 2
Mr = 359.25F(000) = 372
Triclinic, P1Dx = 1.426 Mg m3
Hall symbol: -P 1Melting point = 366–369 K
a = 9.0173 (5) ÅMo Kα radiation, λ = 0.71073 Å
b = 9.2086 (5) ÅCell parameters from 4833 reflections
c = 11.4217 (6) Åθ = 2.4–27.0°
α = 106.752 (1)°µ = 2.47 mm1
β = 106.196 (1)°T = 173 K
γ = 100.353 (1)°Block, colorless
V = 836.51 (8) Å30.47 × 0.40 × 0.21 mm
Data collection top
Bruker SMART 1000 CCD
diffractometer
3237 independent reflections
Radiation source: fine-focus sealed tube2940 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.017
ω scansθmax = 26.0°, θmin = 2.0°
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
h = 1111
Tmin = 0.370, Tmax = 0.594k = 1111
6537 measured reflectionsl = 1411
Refinement top
Refinement on F2Primary atom site location: structure-invariant direct methods
Least-squares matrix: fullSecondary atom site location: difference Fourier map
R[F2 > 2σ(F2)] = 0.025Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.073H-atom parameters constrained
S = 1.08 w = 1/[σ2(Fo2) + (0.0411P)2 + 0.3147P]
where P = (Fo2 + 2Fc2)/3
3237 reflections(Δ/σ)max = 0.002
196 parametersΔρmax = 0.65 e Å3
0 restraintsΔρmin = 0.21 e Å3
Crystal data top
C16H23BrO4γ = 100.353 (1)°
Mr = 359.25V = 836.51 (8) Å3
Triclinic, P1Z = 2
a = 9.0173 (5) ÅMo Kα radiation
b = 9.2086 (5) ŵ = 2.47 mm1
c = 11.4217 (6) ÅT = 173 K
α = 106.752 (1)°0.47 × 0.40 × 0.21 mm
β = 106.196 (1)°
Data collection top
Bruker SMART 1000 CCD
diffractometer
3237 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2004)
2940 reflections with I > 2σ(I)
Tmin = 0.370, Tmax = 0.594Rint = 0.017
6537 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0250 restraints
wR(F2) = 0.073H-atom parameters constrained
S = 1.08Δρmax = 0.65 e Å3
3237 reflectionsΔρmin = 0.21 e Å3
196 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
xyzUiso*/Ueq
Br11.06994 (2)0.86479 (2)0.12181 (2)0.03353 (9)
C10.8126 (2)0.6005 (2)0.07781 (19)0.0234 (4)
H1A0.74580.64590.02160.028*
H1B0.85960.53090.02430.028*
C20.9469 (2)0.7329 (2)0.19069 (19)0.0216 (4)
H20.89960.79930.24770.026*
C31.0691 (2)0.6722 (2)0.27311 (19)0.0224 (4)
C41.1235 (3)0.7470 (3)0.4214 (2)0.0310 (5)
C51.2550 (3)0.6801 (4)0.4841 (3)0.0517 (7)
H5A1.21230.56530.45710.078*
H5B1.28990.72820.57940.078*
H5C1.34680.70390.45600.078*
C61.1885 (3)0.9271 (3)0.4661 (3)0.0466 (6)
H6A1.28150.95330.43990.070*
H6B1.22130.97340.56130.070*
H6C1.10420.96960.42560.070*
C70.9764 (3)0.7038 (3)0.4612 (2)0.0399 (5)
H7A0.89450.75140.42490.060*
H7B1.00950.74390.55660.060*
H7C0.93160.58860.42740.060*
C80.7081 (2)0.5042 (2)0.12787 (18)0.0214 (4)
C90.7162 (2)0.3520 (2)0.12133 (19)0.0230 (4)
H90.79140.31070.08810.028*
C100.6174 (2)0.2603 (2)0.16207 (19)0.0223 (4)
C110.5060 (2)0.3213 (2)0.21148 (19)0.0222 (4)
C120.4989 (2)0.4740 (2)0.22142 (19)0.0222 (4)
H120.42550.51650.25650.027*
C130.5997 (2)0.5642 (2)0.17981 (19)0.0221 (4)
C140.7250 (3)0.0427 (3)0.1048 (2)0.0342 (5)
H14A0.69900.03900.01450.051*
H14B0.71310.06480.10580.051*
H14C0.83610.10740.15630.051*
C150.3096 (3)0.2861 (3)0.3105 (3)0.0386 (5)
H15A0.37600.37720.38970.058*
H15B0.25060.20540.33410.058*
H15C0.23300.31980.25200.058*
C160.4788 (2)0.7768 (2)0.2246 (2)0.0292 (4)
H16A0.37240.70470.16710.044*
H16B0.48660.88110.21720.044*
H16C0.49390.78620.31510.044*
O11.11572 (18)0.56644 (17)0.21908 (15)0.0306 (3)
O20.61793 (17)0.11030 (16)0.15966 (15)0.0291 (3)
O30.41020 (17)0.22188 (16)0.24643 (15)0.0283 (3)
O40.60042 (16)0.71626 (16)0.18717 (15)0.0281 (3)
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.03262 (13)0.02892 (13)0.05128 (16)0.00848 (9)0.02332 (10)0.02369 (10)
C10.0223 (9)0.0241 (9)0.0231 (10)0.0050 (7)0.0070 (8)0.0096 (8)
C20.0217 (9)0.0201 (9)0.0271 (10)0.0059 (7)0.0119 (8)0.0113 (8)
C30.0191 (9)0.0221 (9)0.0260 (10)0.0044 (7)0.0089 (8)0.0089 (8)
C40.0303 (11)0.0362 (12)0.0252 (11)0.0122 (9)0.0077 (9)0.0094 (9)
C50.0510 (15)0.081 (2)0.0325 (13)0.0360 (15)0.0117 (12)0.0258 (13)
C60.0446 (14)0.0386 (13)0.0362 (13)0.0023 (11)0.0065 (11)0.0025 (10)
C70.0466 (14)0.0497 (14)0.0325 (12)0.0184 (11)0.0215 (11)0.0176 (11)
C80.0175 (8)0.0228 (9)0.0216 (9)0.0027 (7)0.0045 (7)0.0088 (7)
C90.0213 (9)0.0241 (9)0.0237 (10)0.0076 (7)0.0076 (8)0.0085 (8)
C100.0228 (9)0.0183 (9)0.0248 (10)0.0059 (7)0.0053 (8)0.0091 (7)
C110.0197 (9)0.0211 (9)0.0231 (9)0.0021 (7)0.0056 (8)0.0083 (7)
C120.0170 (9)0.0219 (9)0.0272 (10)0.0045 (7)0.0076 (8)0.0088 (8)
C130.0194 (9)0.0190 (9)0.0261 (10)0.0044 (7)0.0043 (8)0.0093 (7)
C140.0376 (12)0.0253 (10)0.0515 (14)0.0165 (9)0.0242 (11)0.0175 (10)
C150.0423 (13)0.0280 (11)0.0578 (15)0.0097 (9)0.0332 (12)0.0182 (11)
C160.0277 (10)0.0230 (10)0.0418 (12)0.0104 (8)0.0159 (9)0.0132 (9)
O10.0327 (8)0.0306 (8)0.0337 (8)0.0175 (6)0.0134 (6)0.0121 (6)
O20.0356 (8)0.0218 (7)0.0403 (8)0.0128 (6)0.0209 (7)0.0159 (6)
O30.0285 (7)0.0222 (7)0.0403 (8)0.0058 (6)0.0184 (7)0.0145 (6)
O40.0236 (7)0.0214 (7)0.0473 (9)0.0094 (5)0.0169 (7)0.0177 (6)
Geometric parameters (Å, º) top
Br1—C21.9693 (18)C8—C91.398 (3)
C1—C81.514 (3)C9—C101.382 (3)
C1—C21.519 (3)C9—H90.9500
C1—H1A0.9900C10—O21.374 (2)
C1—H1B0.9900C10—C111.407 (3)
C2—C31.536 (3)C11—O31.365 (2)
C2—H21.0000C11—C121.392 (3)
C3—O11.205 (2)C12—C131.393 (3)
C3—C41.525 (3)C12—H120.9500
C4—C51.530 (3)C13—O41.377 (2)
C4—C61.533 (3)C14—O21.429 (2)
C4—C71.542 (3)C14—H14A0.9800
C5—H5A0.9800C14—H14B0.9800
C5—H5B0.9800C14—H14C0.9800
C5—H5C0.9800C15—O31.422 (3)
C6—H6A0.9800C15—H15A0.9800
C6—H6B0.9800C15—H15B0.9800
C6—H6C0.9800C15—H15C0.9800
C7—H7A0.9800C16—O41.428 (2)
C7—H7B0.9800C16—H16A0.9800
C7—H7C0.9800C16—H16B0.9800
C8—C131.393 (3)C16—H16C0.9800
C8—C1—C2110.66 (16)C13—C8—C9118.31 (17)
C8—C1—H1A109.5C13—C8—C1120.84 (17)
C2—C1—H1A109.5C9—C8—C1120.84 (17)
C8—C1—H1B109.5C10—C9—C8121.62 (18)
C2—C1—H1B109.5C10—C9—H9119.2
H1A—C1—H1B108.1C8—C9—H9119.2
C1—C2—C3112.96 (15)O2—C10—C9125.42 (17)
C1—C2—Br1109.43 (13)O2—C10—C11115.27 (17)
C3—C2—Br1105.97 (12)C9—C10—C11119.30 (17)
C1—C2—H2109.5O3—C11—C12124.48 (17)
C3—C2—H2109.5O3—C11—C10115.70 (16)
Br1—C2—H2109.5C12—C11—C10119.82 (17)
O1—C3—C4122.68 (18)C11—C12—C13119.80 (17)
O1—C3—C2119.30 (17)C11—C12—H12120.1
C4—C3—C2118.00 (16)C13—C12—H12120.1
C3—C4—C5109.50 (18)O4—C13—C12123.22 (17)
C3—C4—C6110.49 (19)O4—C13—C8115.67 (17)
C5—C4—C6109.6 (2)C12—C13—C8121.11 (17)
C3—C4—C7107.65 (17)O2—C14—H14A109.5
C5—C4—C7109.5 (2)O2—C14—H14B109.5
C6—C4—C7110.09 (19)H14A—C14—H14B109.5
C4—C5—H5A109.5O2—C14—H14C109.5
C4—C5—H5B109.5H14A—C14—H14C109.5
H5A—C5—H5B109.5H14B—C14—H14C109.5
C4—C5—H5C109.5O3—C15—H15A109.5
H5A—C5—H5C109.5O3—C15—H15B109.5
H5B—C5—H5C109.5H15A—C15—H15B109.5
C4—C6—H6A109.5O3—C15—H15C109.5
C4—C6—H6B109.5H15A—C15—H15C109.5
H6A—C6—H6B109.5H15B—C15—H15C109.5
C4—C6—H6C109.5O4—C16—H16A109.5
H6A—C6—H6C109.5O4—C16—H16B109.5
H6B—C6—H6C109.5H16A—C16—H16B109.5
C4—C7—H7A109.5O4—C16—H16C109.5
C4—C7—H7B109.5H16A—C16—H16C109.5
H7A—C7—H7B109.5H16B—C16—H16C109.5
C4—C7—H7C109.5C10—O2—C14116.49 (15)
H7A—C7—H7C109.5C11—O3—C15116.98 (15)
H7B—C7—H7C109.5C13—O4—C16118.02 (15)
C8—C1—C2—C366.5 (2)O2—C10—C11—O32.0 (2)
C8—C1—C2—Br1175.74 (12)C9—C10—C11—O3178.37 (17)
C1—C2—C3—O143.4 (2)O2—C10—C11—C12178.26 (17)
Br1—C2—C3—O176.38 (19)C9—C10—C11—C121.4 (3)
C1—C2—C3—C4135.17 (18)O3—C11—C12—C13178.37 (18)
Br1—C2—C3—C4105.03 (17)C10—C11—C12—C131.4 (3)
O1—C3—C4—C56.3 (3)C11—C12—C13—O4179.61 (17)
C2—C3—C4—C5175.18 (19)C11—C12—C13—C80.1 (3)
O1—C3—C4—C6127.1 (2)C9—C8—C13—O4178.22 (17)
C2—C3—C4—C654.3 (2)C1—C8—C13—O42.7 (3)
O1—C3—C4—C7112.6 (2)C9—C8—C13—C121.5 (3)
C2—C3—C4—C765.9 (2)C1—C8—C13—C12177.52 (18)
C2—C1—C8—C1374.0 (2)C9—C10—O2—C143.0 (3)
C2—C1—C8—C9107.0 (2)C11—C10—O2—C14177.39 (18)
C13—C8—C9—C101.5 (3)C12—C11—O3—C157.3 (3)
C1—C8—C9—C10177.55 (18)C10—C11—O3—C15172.93 (18)
C8—C9—C10—O2179.66 (18)C12—C13—O4—C167.7 (3)
C8—C9—C10—C110.1 (3)C8—C13—O4—C16172.52 (17)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C2—H2···O41.002.503.089 (2)117
C16—H16B···O2i0.982.573.465 (3)151
Symmetry code: (i) x, y+1, z.

Experimental details

Crystal data
Chemical formulaC16H23BrO4
Mr359.25
Crystal system, space groupTriclinic, P1
Temperature (K)173
a, b, c (Å)9.0173 (5), 9.2086 (5), 11.4217 (6)
α, β, γ (°)106.752 (1), 106.196 (1), 100.353 (1)
V3)836.51 (8)
Z2
Radiation typeMo Kα
µ (mm1)2.47
Crystal size (mm)0.47 × 0.40 × 0.21
Data collection
DiffractometerBruker SMART 1000 CCD
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2004)
Tmin, Tmax0.370, 0.594
No. of measured, independent and
observed [I > 2σ(I)] reflections
6537, 3237, 2940
Rint0.017
(sin θ/λ)max1)0.617
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.025, 0.073, 1.08
No. of reflections3237
No. of parameters196
H-atom treatmentH-atom parameters constrained
Δρmax, Δρmin (e Å3)0.65, 0.21

Computer programs: SMART (Bruker, 2001), SAINT-Plus (Bruker, 2003), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
C2—H2···O41.00002.50003.089 (2)117.00
C16—H16B···O2i0.98002.57003.465 (3)151.00
Symmetry code: (i) x, y+1, z.
 

Acknowledgements

This work was funded by the SIT program of Hunan University (2008).

References

First citationBruker (2001). SMART. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruker (2003). SAINT-Plus. Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationBruker (2004). SADABS Bruker AXS Inc., Madison, Wisconsin, USA.  Google Scholar
First citationHu, A.-X., Cao, G., Xu, J.-J., Xia, L. & He, D.-H. (2007). J. Hunan Univ. (Nat. Sci.), 34, 78–81.  CAS Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar
First citationXu, J.-J., Hu, A.-X. & Cao, G. (2007). Acta Cryst. E63, o533–o534.  Web of Science CSD CrossRef IUCr Journals Google Scholar

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