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

Tang, L.-L.; Ye, J.; Liu, Q.-X.; Hu, A.-X.

doi:10.1107/S1600536809018601

organic compounds

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ISSN: 2056-9890

Volume 65| Part 6| June 2009| Page o1359

doi:10.1107/S1600536809018601

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

Lin-Lin Tang,^a Jiao Ye,^a Qi-Xing Liu ^a and Ai-Xi Hu ^a ^*

^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 ); Hu et al. (2007 ).

Experimental

Crystal data

C₁₆H₂₃BrO₄
M_r = 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 ) T_min = 0.370, T_max = 0.594
6537 measured reflections
3237 independent reflections
2940 reflections with I > 2σ(I)
R_int = 0.017

Refinement

R[F² > 2σ(F²)] = 0.025
wR(F²) = 0.073
S = 1.08
3237 reflections
196 parameters
H-atom parameters constrained
Δρ_max = 0.65 e Å⁻³
Δρ_min = −0.21 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	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 ); cell refinement: SAINT-Plus (Bruker, 2003 ); data reduction: SAINT-Plus; program(s) used to solve structure: SHELXTL (Sheldrick, 2008 ); program(s) used to refine structure: SHELXTL; molecular graphics: SHELXTL; software used to prepare material for publication: SHELXTL.

Supporting information

Crystal structure: contains datablocks I, global. DOI: 10.1107/S1600536809018601/bt2955sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536809018601/bt2955Isup2.hkl

checkCIF report

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.

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

	Fig. 1. Molecular structure showing 30% probability displacement ellipsoids.
	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

C₁₆H₂₃BrO₄	Z = 2
M_r = 359.25	F(000) = 372
Triclinic, P1	D_x = 1.426 Mg m⁻³
Hall symbol: -P 1	Melting point = 366–369 K
a = 9.0173 (5) Å	Mo Kα radiation, λ = 0.71073 Å
b = 9.2086 (5) Å	Cell parameters from 4833 reflections
c = 11.4217 (6) Å	θ = 2.4–27.0°
α = 106.752 (1)°	µ = 2.47 mm⁻¹
β = 106.196 (1)°	T = 173 K
γ = 100.353 (1)°	Block, colorless
V = 836.51 (8) Å³	0.47 × 0.40 × 0.21 mm

Data collection top

Bruker SMART 1000 CCD diffractometer	3237 independent reflections
Radiation source: fine-focus sealed tube	2940 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.017
ω scans	θ_max = 26.0°, θ_min = 2.0°
Absorption correction: multi-scan (SADABS; Bruker, 2004)	h = −11→11
T_min = 0.370, T_max = 0.594	k = −11→11
6537 measured reflections	l = −14→11

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)] = 0.025	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.073	H-atom parameters constrained
S = 1.08	w = 1/[σ²(F_o²) + (0.0411P)² + 0.3147P] where P = (F_o² + 2F_c²)/3
3237 reflections	(Δ/σ)_max = 0.002
196 parameters	Δρ_max = 0.65 e Å⁻³
0 restraints	Δρ_min = −0.21 e Å⁻³

Crystal data top

C₁₆H₂₃BrO₄	γ = 100.353 (1)°
M_r = 359.25	V = 836.51 (8) Å³
Triclinic, P1	Z = 2
a = 9.0173 (5) Å	Mo Kα radiation
b = 9.2086 (5) Å	µ = 2.47 mm⁻¹
c = 11.4217 (6) Å	T = 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)
T_min = 0.370, T_max = 0.594	R_int = 0.017
6537 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.025	0 restraints
wR(F²) = 0.073	H-atom parameters constrained
S = 1.08	Δρ_max = 0.65 e Å⁻³
3237 reflections	Δρ_min = −0.21 e Å⁻³
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

	x	y	z	U_iso*/U_eq
Br1	1.06994 (2)	0.86479 (2)	0.12181 (2)	0.03353 (9)
C1	0.8126 (2)	0.6005 (2)	0.07781 (19)	0.0234 (4)
H1A	0.7458	0.6459	0.0216	0.028*
H1B	0.8596	0.5309	0.0243	0.028*
C2	0.9469 (2)	0.7329 (2)	0.19069 (19)	0.0216 (4)
H2	0.8996	0.7993	0.2477	0.026*
C3	1.0691 (2)	0.6722 (2)	0.27311 (19)	0.0224 (4)
C4	1.1235 (3)	0.7470 (3)	0.4214 (2)	0.0310 (5)
C5	1.2550 (3)	0.6801 (4)	0.4841 (3)	0.0517 (7)
H5A	1.2123	0.5653	0.4571	0.078*
H5B	1.2899	0.7282	0.5794	0.078*
H5C	1.3468	0.7039	0.4560	0.078*
C6	1.1885 (3)	0.9271 (3)	0.4661 (3)	0.0466 (6)
H6A	1.2815	0.9533	0.4399	0.070*
H6B	1.2213	0.9734	0.5613	0.070*
H6C	1.1042	0.9696	0.4256	0.070*
C7	0.9764 (3)	0.7038 (3)	0.4612 (2)	0.0399 (5)
H7A	0.8945	0.7514	0.4249	0.060*
H7B	1.0095	0.7439	0.5566	0.060*
H7C	0.9316	0.5886	0.4274	0.060*
C8	0.7081 (2)	0.5042 (2)	0.12787 (18)	0.0214 (4)
C9	0.7162 (2)	0.3520 (2)	0.12133 (19)	0.0230 (4)
H9	0.7914	0.3107	0.0881	0.028*
C10	0.6174 (2)	0.2603 (2)	0.16207 (19)	0.0223 (4)
C11	0.5060 (2)	0.3213 (2)	0.21148 (19)	0.0222 (4)
C12	0.4989 (2)	0.4740 (2)	0.22142 (19)	0.0222 (4)
H12	0.4255	0.5165	0.2565	0.027*
C13	0.5997 (2)	0.5642 (2)	0.17981 (19)	0.0221 (4)
C14	0.7250 (3)	0.0427 (3)	0.1048 (2)	0.0342 (5)
H14A	0.6990	0.0390	0.0145	0.051*
H14B	0.7131	−0.0648	0.1058	0.051*
H14C	0.8361	0.1074	0.1563	0.051*
C15	0.3096 (3)	0.2861 (3)	0.3105 (3)	0.0386 (5)
H15A	0.3760	0.3772	0.3897	0.058*
H15B	0.2506	0.2054	0.3341	0.058*
H15C	0.2330	0.3198	0.2520	0.058*
C16	0.4788 (2)	0.7768 (2)	0.2246 (2)	0.0292 (4)
H16A	0.3724	0.7047	0.1671	0.044*
H16B	0.4866	0.8811	0.2172	0.044*
H16C	0.4939	0.7862	0.3151	0.044*
O1	1.11572 (18)	0.56644 (17)	0.21908 (15)	0.0306 (3)
O2	0.61793 (17)	0.11030 (16)	0.15966 (15)	0.0291 (3)
O3	0.41020 (17)	0.22188 (16)	0.24643 (15)	0.0283 (3)
O4	0.60042 (16)	0.71626 (16)	0.18717 (15)	0.0281 (3)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.03262 (13)	0.02892 (13)	0.05128 (16)	0.00848 (9)	0.02332 (10)	0.02369 (10)
C1	0.0223 (9)	0.0241 (9)	0.0231 (10)	0.0050 (7)	0.0070 (8)	0.0096 (8)
C2	0.0217 (9)	0.0201 (9)	0.0271 (10)	0.0059 (7)	0.0119 (8)	0.0113 (8)
C3	0.0191 (9)	0.0221 (9)	0.0260 (10)	0.0044 (7)	0.0089 (8)	0.0089 (8)
C4	0.0303 (11)	0.0362 (12)	0.0252 (11)	0.0122 (9)	0.0077 (9)	0.0094 (9)
C5	0.0510 (15)	0.081 (2)	0.0325 (13)	0.0360 (15)	0.0117 (12)	0.0258 (13)
C6	0.0446 (14)	0.0386 (13)	0.0362 (13)	0.0023 (11)	0.0065 (11)	−0.0025 (10)
C7	0.0466 (14)	0.0497 (14)	0.0325 (12)	0.0184 (11)	0.0215 (11)	0.0176 (11)
C8	0.0175 (8)	0.0228 (9)	0.0216 (9)	0.0027 (7)	0.0045 (7)	0.0088 (7)
C9	0.0213 (9)	0.0241 (9)	0.0237 (10)	0.0076 (7)	0.0076 (8)	0.0085 (8)
C10	0.0228 (9)	0.0183 (9)	0.0248 (10)	0.0059 (7)	0.0053 (8)	0.0091 (7)
C11	0.0197 (9)	0.0211 (9)	0.0231 (9)	0.0021 (7)	0.0056 (8)	0.0083 (7)
C12	0.0170 (9)	0.0219 (9)	0.0272 (10)	0.0045 (7)	0.0076 (8)	0.0088 (8)
C13	0.0194 (9)	0.0190 (9)	0.0261 (10)	0.0044 (7)	0.0043 (8)	0.0093 (7)
C14	0.0376 (12)	0.0253 (10)	0.0515 (14)	0.0165 (9)	0.0242 (11)	0.0175 (10)
C15	0.0423 (13)	0.0280 (11)	0.0578 (15)	0.0097 (9)	0.0332 (12)	0.0182 (11)
C16	0.0277 (10)	0.0230 (10)	0.0418 (12)	0.0104 (8)	0.0159 (9)	0.0132 (9)
O1	0.0327 (8)	0.0306 (8)	0.0337 (8)	0.0175 (6)	0.0134 (6)	0.0121 (6)
O2	0.0356 (8)	0.0218 (7)	0.0403 (8)	0.0128 (6)	0.0209 (7)	0.0159 (6)
O3	0.0285 (7)	0.0222 (7)	0.0403 (8)	0.0058 (6)	0.0184 (7)	0.0145 (6)
O4	0.0236 (7)	0.0214 (7)	0.0473 (9)	0.0094 (5)	0.0169 (7)	0.0177 (6)

Geometric parameters (Å, º) top

Br1—C2	1.9693 (18)	C8—C9	1.398 (3)
C1—C8	1.514 (3)	C9—C10	1.382 (3)
C1—C2	1.519 (3)	C9—H9	0.9500
C1—H1A	0.9900	C10—O2	1.374 (2)
C1—H1B	0.9900	C10—C11	1.407 (3)
C2—C3	1.536 (3)	C11—O3	1.365 (2)
C2—H2	1.0000	C11—C12	1.392 (3)
C3—O1	1.205 (2)	C12—C13	1.393 (3)
C3—C4	1.525 (3)	C12—H12	0.9500
C4—C5	1.530 (3)	C13—O4	1.377 (2)
C4—C6	1.533 (3)	C14—O2	1.429 (2)
C4—C7	1.542 (3)	C14—H14A	0.9800
C5—H5A	0.9800	C14—H14B	0.9800
C5—H5B	0.9800	C14—H14C	0.9800
C5—H5C	0.9800	C15—O3	1.422 (3)
C6—H6A	0.9800	C15—H15A	0.9800
C6—H6B	0.9800	C15—H15B	0.9800
C6—H6C	0.9800	C15—H15C	0.9800
C7—H7A	0.9800	C16—O4	1.428 (2)
C7—H7B	0.9800	C16—H16A	0.9800
C7—H7C	0.9800	C16—H16B	0.9800
C8—C13	1.393 (3)	C16—H16C	0.9800

C8—C1—C2	110.66 (16)	C13—C8—C9	118.31 (17)
C8—C1—H1A	109.5	C13—C8—C1	120.84 (17)
C2—C1—H1A	109.5	C9—C8—C1	120.84 (17)
C8—C1—H1B	109.5	C10—C9—C8	121.62 (18)
C2—C1—H1B	109.5	C10—C9—H9	119.2
H1A—C1—H1B	108.1	C8—C9—H9	119.2
C1—C2—C3	112.96 (15)	O2—C10—C9	125.42 (17)
C1—C2—Br1	109.43 (13)	O2—C10—C11	115.27 (17)
C3—C2—Br1	105.97 (12)	C9—C10—C11	119.30 (17)
C1—C2—H2	109.5	O3—C11—C12	124.48 (17)
C3—C2—H2	109.5	O3—C11—C10	115.70 (16)
Br1—C2—H2	109.5	C12—C11—C10	119.82 (17)
O1—C3—C4	122.68 (18)	C11—C12—C13	119.80 (17)
O1—C3—C2	119.30 (17)	C11—C12—H12	120.1
C4—C3—C2	118.00 (16)	C13—C12—H12	120.1
C3—C4—C5	109.50 (18)	O4—C13—C12	123.22 (17)
C3—C4—C6	110.49 (19)	O4—C13—C8	115.67 (17)
C5—C4—C6	109.6 (2)	C12—C13—C8	121.11 (17)
C3—C4—C7	107.65 (17)	O2—C14—H14A	109.5
C5—C4—C7	109.5 (2)	O2—C14—H14B	109.5
C6—C4—C7	110.09 (19)	H14A—C14—H14B	109.5
C4—C5—H5A	109.5	O2—C14—H14C	109.5
C4—C5—H5B	109.5	H14A—C14—H14C	109.5
H5A—C5—H5B	109.5	H14B—C14—H14C	109.5
C4—C5—H5C	109.5	O3—C15—H15A	109.5
H5A—C5—H5C	109.5	O3—C15—H15B	109.5
H5B—C5—H5C	109.5	H15A—C15—H15B	109.5
C4—C6—H6A	109.5	O3—C15—H15C	109.5
C4—C6—H6B	109.5	H15A—C15—H15C	109.5
H6A—C6—H6B	109.5	H15B—C15—H15C	109.5
C4—C6—H6C	109.5	O4—C16—H16A	109.5
H6A—C6—H6C	109.5	O4—C16—H16B	109.5
H6B—C6—H6C	109.5	H16A—C16—H16B	109.5
C4—C7—H7A	109.5	O4—C16—H16C	109.5
C4—C7—H7B	109.5	H16A—C16—H16C	109.5
H7A—C7—H7B	109.5	H16B—C16—H16C	109.5
C4—C7—H7C	109.5	C10—O2—C14	116.49 (15)
H7A—C7—H7C	109.5	C11—O3—C15	116.98 (15)
H7B—C7—H7C	109.5	C13—O4—C16	118.02 (15)

C8—C1—C2—C3	66.5 (2)	O2—C10—C11—O3	−2.0 (2)
C8—C1—C2—Br1	−175.74 (12)	C9—C10—C11—O3	178.37 (17)
C1—C2—C3—O1	43.4 (2)	O2—C10—C11—C12	178.26 (17)
Br1—C2—C3—O1	−76.38 (19)	C9—C10—C11—C12	−1.4 (3)
C1—C2—C3—C4	−135.17 (18)	O3—C11—C12—C13	−178.37 (18)
Br1—C2—C3—C4	105.03 (17)	C10—C11—C12—C13	1.4 (3)
O1—C3—C4—C5	6.3 (3)	C11—C12—C13—O4	−179.61 (17)
C2—C3—C4—C5	−175.18 (19)	C11—C12—C13—C8	0.1 (3)
O1—C3—C4—C6	127.1 (2)	C9—C8—C13—O4	178.22 (17)
C2—C3—C4—C6	−54.3 (2)	C1—C8—C13—O4	−2.7 (3)
O1—C3—C4—C7	−112.6 (2)	C9—C8—C13—C12	−1.5 (3)
C2—C3—C4—C7	65.9 (2)	C1—C8—C13—C12	177.52 (18)
C2—C1—C8—C13	74.0 (2)	C9—C10—O2—C14	−3.0 (3)
C2—C1—C8—C9	−107.0 (2)	C11—C10—O2—C14	177.39 (18)
C13—C8—C9—C10	1.5 (3)	C12—C11—O3—C15	−7.3 (3)
C1—C8—C9—C10	−177.55 (18)	C10—C11—O3—C15	172.93 (18)
C8—C9—C10—O2	−179.66 (18)	C12—C13—O4—C16	−7.7 (3)
C8—C9—C10—C11	−0.1 (3)	C8—C13—O4—C16	172.52 (17)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	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.

Experimental details

Crystal data
Chemical formula	C₁₆H₂₃BrO₄
M_r	359.25
Crystal system, space group	Triclinic, 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)
V (Å³)	836.51 (8)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	2.47
Crystal size (mm)	0.47 × 0.40 × 0.21

Data collection
Diffractometer	Bruker SMART 1000 CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2004)
T_min, T_max	0.370, 0.594
No. of measured, independent and observed [I > 2σ(I)] reflections	6537, 3237, 2940
R_int	0.017
(sin θ/λ)_max (Å⁻¹)	0.617

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.025, 0.073, 1.08
No. of reflections	3237
No. of parameters	196
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.65, −0.21

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

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C2—H2···O4	1.0000	2.5000	3.089 (2)	117.00
C16—H16B···O2ⁱ	0.9800	2.5700	3.465 (3)	151.00

Symmetry code: (i) x, y+1, z.

Acknowledgements

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

References

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