2-Oxo-4-trifluoro­meth­yl-2H-chromen-7-yl 2-bromo-2-methyl­propano­ate

Haridharan, N.; Ramkumar, V.; Dhamodharan, R.

doi:10.1107/S1600536810020234

organic compounds

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ISSN: 2056-9890

Volume 66| Part 7| July 2010| Page o1606

doi:10.1107/S1600536810020234

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2-Oxo-4-trifluoromethyl-2H-chromen-7-yl 2-bromo-2-methylpropanoate

N. Haridharan,^a V. Ramkumar ^a and R. Dhamodharan ^a ^*

^aDepartment of Chemistry, IIT Madras, Chennai, TamilNadu, India
^*Correspondence e-mail: damo@iitm.ac.in

(Received 13 May 2010; accepted 28 May 2010; online 9 June 2010)

In the title compound, C₁₄H₁₀BrF₃O₄, the coumarin ring system is almost plannar (r.m.s. deviation = 0.025 Å) and a short C—H⋯F contact occurs. The propanoate fragment is orientated almost perpendicular to the ring [dihedral angle = 71.80 (12)°]. In the crystal, molecules are linked by C—H⋯O hydrogen bonds, generating [100] chains.

Related literature

For the applications of the title compound in polymer chemistry, see: Sinkel et al. (2008 ); Matyjaszewski et al. (2008 ); Stenzel-Rosenbaum et al. (2001 ).

Experimental

Crystal data

C₁₄H₁₀BrF₃O₄
M_r = 379.13
Triclinic, $[P \overline 1]$
a = 6.1842 (4) Å
b = 11.0297 (6) Å
c = 11.0619 (7) Å
α = 99.982 (2)°
β = 91.797 (2)°
γ = 104.387 (2)°
V = 717.61 (8) Å³
Z = 2
Mo Kα radiation
μ = 2.91 mm⁻¹
T = 298 K
0.40 × 0.26 × 0.24 mm

Data collection

Bruker APEXII CCD diffractometer
Absorption correction: multi-scan (SADABS; Bruker, 2004 ) T_min = 0.389, T_max = 0.542
9951 measured reflections
3796 independent reflections
2390 reflections with I > 2σ(I)
R_int = 0.022

Refinement

R[F² > 2σ(F²)] = 0.040
wR(F²) = 0.109
S = 1.01
3796 reflections
201 parameters
H-atom parameters constrained
Δρ_max = 0.78 e Å⁻³
Δρ_min = −0.85 e Å⁻³

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A	D—H	H⋯A	D⋯A	D—H⋯A
C5—H5⋯F2	0.93	2.47	3.019 (3)	118
C6—H6⋯O4ⁱ	0.93	2.52	3.261 (4)	136
Symmetry code: (i) x+1, y, z.

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus and XPREP (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008 ); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997 ); software used to prepare material for publication: SHELXL97.

Supporting information

Crystal structure: contains datablocks global, I. DOI: 10.1107/S1600536810020234/hb5450sup1.cif

Structure factors: contains datablock I. DOI: 10.1107/S1600536810020234/hb5450Isup2.hkl

checkCIF report

Comment top

The title compound C₁₄H₁₀BrF₃O₄, is a monofunctional coumarin derivative, which is used as an initiator (Sinkel et al. 2008) in Atom Transfer Radical Polymerization (ATRP). Being a monofunctional unit it can form end-functionalized linear polymers (Matyjaszewski et al. 2008; Stenzel-Rosenbaum et al.2001) when used as an initiator. Since most of the synthesized functionalized initiators are characterized by other techniques, their single crystal XRD reports are few.

The title compound is one such successful ATRP initiator which was crystallised from chloroform. It contains coumarin derivative with bromo methyl propanoate. The coumarin moiety is an important oxygen containing heterocyclic compound with diverse bioactivities such as non peptidic HIV protease inhibition and tyrosine kinase inhibition. Owing to such interesting properties, the synthesis of coumarin based initiators and their crystal structures are worth while to study.

In the title compound C₁₄ H₁₀ Br F₃ O₄, the coumarin ring system is plannar with the 2-bromo-2-methyl propanoate moiety almost perpendicular. The C—F bond lengths of 1.333 (2) Å,1.324 (3)Å and 1.331 (3)Å are normal in this structure. One F atom (F1) lie in plane with the coumarin ring system and the other two F atoms are above and below the plane. The torsion angle of C6—C7—O3—C11 and C8—C7—O3—C11 are -114.21 (3)° and 71.42 (2)° respectively. The crystal is stabilized by intermolecular C—H···O hydrogen bond.

Related literature top

For the applications of the title compound in polymer chemistry, see: Sinkel et al. (2008); Matyjaszewski et al. (2008); Stenzel-Rosenbaum et al. (2001).

Experimental top

7-Hydroxy-4-trifluoromethylcoumarin 5 g (0.02 mole), triethylamine 4.83 g (0.04 mole) and THF (400 ml) were placed in a 3-neck round bottomed flask. Bromoisobutyrl bromide 10.9 g (0.04 mole) was added slowly, using a syringe, with stirring, upon which an white precipitate of triethylammonium bromide was formed. The mixture was left to react for 6 hours, with stirring. Subsequently, triethylammonium bromide, the precipitate was removed by filtration and the THF was removed by rotary evaporation. The resulting crude product was dissolved in ethyl acetate, washed with bicarbonate solution and then with water thrice followed by brine solution and dried over anhydrous sodium sulphate. The resulting solvent was removed by rotary evaporation. The product was purified by column chromatography technique using 15% ethyl acetate in hexane as the eluent to obtain pure initiator as a bright white solid. Recrystallization of the compound from chloroform gave colourless blocks of (I).

Computing details top

Data collection: APEX2 (Bruker, 2004); cell refinement: SAINT-Plus (Bruker, 2004); data reduction: SAINT-Plus and XPREP (Bruker, 2004); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008); molecular graphics: ORTEP-3 (Farrugia, 1997); software used to prepare material for publication: SHELXL97 (Sheldrick, 2008).

Figures top

	Fig. 1. View of (I) with atoms represented as 30% probability ellipsoids.
	Fig. 2. The packing diagram showing the C—H···O interaction.

2-Oxo-4-trifluoromethyl-2H-chromen-7-yl 2-bromo-2-methylpropanoate top

Crystal data top

C₁₄H₁₀BrF₃O₄	Z = 2
M_r = 379.13	F(000) = 376
Triclinic, P1	D_x = 1.755 Mg m⁻³
Hall symbol: -P 1	Mo Kα radiation, λ = 0.71073 Å
a = 6.1842 (4) Å	Cell parameters from 3404 reflections
b = 11.0297 (6) Å	θ = 2.4–25.3°
c = 11.0619 (7) Å	µ = 2.91 mm⁻¹
α = 99.982 (2)°	T = 298 K
β = 91.797 (2)°	Rectangular, colourless
γ = 104.387 (2)°	0.40 × 0.26 × 0.24 mm
V = 717.61 (8) Å³

Data collection top

Bruker APEXII CCD diffractometer	3796 independent reflections
Radiation source: fine-focus sealed tube	2390 reflections with I > 2σ(I)
Graphite monochromator	R_int = 0.022
phi and ω scans	θ_max = 30.8°, θ_min = 1.9°
Absorption correction: multi-scan (SADABS; Bruker, 2004)	h = −7→8
T_min = 0.389, T_max = 0.542	k = −15→14
9951 measured reflections	l = −13→15

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)] = 0.040	Hydrogen site location: inferred from neighbouring sites
wR(F²) = 0.109	H-atom parameters constrained
S = 1.01	w = 1/[σ²(F_o²) + (0.0464P)² + 0.448P] where P = (F_o² + 2F_c²)/3
3796 reflections	(Δ/σ)_max < 0.001
201 parameters	Δρ_max = 0.78 e Å⁻³
0 restraints	Δρ_min = −0.85 e Å⁻³

Crystal data top

C₁₄H₁₀BrF₃O₄	γ = 104.387 (2)°
M_r = 379.13	V = 717.61 (8) Å³
Triclinic, P1	Z = 2
a = 6.1842 (4) Å	Mo Kα radiation
b = 11.0297 (6) Å	µ = 2.91 mm⁻¹
c = 11.0619 (7) Å	T = 298 K
α = 99.982 (2)°	0.40 × 0.26 × 0.24 mm
β = 91.797 (2)°

Data collection top

Bruker APEXII CCD diffractometer	3796 independent reflections
Absorption correction: multi-scan (SADABS; Bruker, 2004)	2390 reflections with I > 2σ(I)
T_min = 0.389, T_max = 0.542	R_int = 0.022
9951 measured reflections

Refinement top

R[F² > 2σ(F²)] = 0.040	0 restraints
wR(F²) = 0.109	H-atom parameters constrained
S = 1.01	Δρ_max = 0.78 e Å⁻³
3796 reflections	Δρ_min = −0.85 e Å⁻³
201 parameters

Special details top

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.

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	0.06908 (6)	−0.04175 (3)	0.29516 (4)	0.06662 (16)
C1	0.2614 (5)	0.5339 (3)	−0.2219 (3)	0.0450 (7)
C2	0.4147 (5)	0.4806 (3)	−0.2966 (3)	0.0450 (7)
H2	0.4574	0.5118	−0.3675	0.054*
C3	0.4972 (4)	0.3873 (3)	−0.2666 (2)	0.0363 (6)
C4	0.4377 (4)	0.3379 (2)	−0.1559 (2)	0.0322 (5)
C5	0.5183 (4)	0.2437 (3)	−0.1127 (2)	0.0375 (6)
H5	0.6232	0.2098	−0.1557	0.045*
C6	0.4449 (5)	0.2007 (3)	−0.0080 (3)	0.0408 (6)
H6	0.4995	0.1385	0.0202	0.049*
C7	0.2881 (4)	0.2518 (3)	0.0548 (2)	0.0359 (6)
C8	0.2074 (4)	0.3459 (3)	0.0179 (2)	0.0386 (6)
H8	0.1041	0.3801	0.0622	0.046*
C9	0.2849 (4)	0.3880 (2)	−0.0872 (2)	0.0333 (6)
C10	0.6453 (5)	0.3300 (3)	−0.3523 (3)	0.0464 (7)
C11	0.0108 (4)	0.1442 (3)	0.1690 (3)	0.0361 (6)
C12	−0.0307 (4)	0.1167 (3)	0.2974 (3)	0.0389 (6)
C13	0.1076 (6)	0.2198 (3)	0.4010 (3)	0.0541 (8)
H13A	0.2639	0.2317	0.3887	0.081*
H13B	0.0784	0.1940	0.4787	0.081*
H13C	0.0672	0.2983	0.4005	0.081*
C14	−0.2790 (5)	0.0855 (3)	0.3145 (3)	0.0516 (8)
H14A	−0.3331	0.1596	0.3129	0.077*
H14B	−0.3045	0.0591	0.3923	0.077*
H14C	−0.3569	0.0179	0.2493	0.077*
F1	0.6893 (4)	0.3893 (2)	−0.44723 (18)	0.0775 (6)
F2	0.8423 (3)	0.3353 (2)	−0.29621 (18)	0.0652 (5)
F3	0.5518 (3)	0.20819 (19)	−0.39741 (17)	0.0645 (5)
O1	0.2025 (3)	0.48421 (18)	−0.11926 (17)	0.0429 (5)
O2	0.1777 (4)	0.6161 (2)	−0.2441 (2)	0.0648 (6)
O3	0.2269 (3)	0.2130 (2)	0.16562 (17)	0.0452 (5)
O4	−0.1216 (3)	0.1118 (2)	0.08271 (19)	0.0498 (5)

Atomic displacement parameters (Å²) top

	U¹¹	U²²	U³³	U¹²	U¹³	U²³
Br1	0.0781 (3)	0.0645 (3)	0.0835 (3)	0.04411 (19)	0.0312 (2)	0.0426 (2)
C1	0.0603 (18)	0.0383 (16)	0.0422 (16)	0.0201 (13)	0.0037 (14)	0.0123 (13)
C2	0.0613 (18)	0.0436 (17)	0.0361 (15)	0.0170 (13)	0.0083 (13)	0.0174 (13)
C3	0.0408 (14)	0.0373 (15)	0.0311 (13)	0.0087 (11)	0.0039 (11)	0.0083 (11)
C4	0.0354 (13)	0.0320 (13)	0.0301 (13)	0.0100 (10)	0.0012 (11)	0.0066 (11)
C5	0.0398 (14)	0.0386 (15)	0.0398 (15)	0.0179 (11)	0.0082 (12)	0.0103 (12)
C6	0.0420 (15)	0.0426 (16)	0.0436 (16)	0.0157 (12)	0.0015 (13)	0.0166 (13)
C7	0.0355 (13)	0.0419 (15)	0.0314 (13)	0.0071 (11)	0.0006 (11)	0.0141 (12)
C8	0.0399 (14)	0.0448 (16)	0.0359 (14)	0.0165 (12)	0.0090 (12)	0.0114 (12)
C9	0.0371 (13)	0.0322 (13)	0.0343 (14)	0.0136 (11)	−0.0003 (11)	0.0097 (11)
C10	0.0507 (17)	0.055 (2)	0.0388 (16)	0.0182 (14)	0.0111 (13)	0.0158 (14)
C11	0.0355 (13)	0.0387 (15)	0.0409 (15)	0.0163 (11)	0.0076 (12)	0.0150 (12)
C12	0.0410 (14)	0.0400 (15)	0.0434 (16)	0.0164 (12)	0.0110 (12)	0.0184 (13)
C13	0.063 (2)	0.062 (2)	0.0375 (16)	0.0097 (16)	0.0049 (14)	0.0203 (15)
C14	0.0483 (17)	0.0514 (18)	0.060 (2)	0.0164 (14)	0.0240 (15)	0.0162 (16)
F1	0.1027 (17)	0.1013 (16)	0.0556 (12)	0.0515 (13)	0.0434 (12)	0.0444 (12)
F2	0.0437 (10)	0.0907 (15)	0.0663 (12)	0.0224 (10)	0.0112 (9)	0.0201 (11)
F3	0.0773 (13)	0.0584 (12)	0.0548 (11)	0.0235 (10)	0.0128 (10)	−0.0077 (9)
O1	0.0573 (12)	0.0422 (11)	0.0403 (11)	0.0277 (9)	0.0093 (9)	0.0146 (9)
O2	0.0941 (18)	0.0559 (14)	0.0647 (15)	0.0455 (13)	0.0132 (13)	0.0270 (12)
O3	0.0371 (10)	0.0647 (13)	0.0372 (10)	0.0071 (9)	0.0029 (8)	0.0271 (9)
O4	0.0422 (11)	0.0607 (13)	0.0453 (12)	0.0078 (9)	−0.0033 (10)	0.0161 (10)

Geometric parameters (Å, º) top

Br1—C12	1.990 (3)	C8—H8	0.9300
C1—O2	1.205 (3)	C9—O1	1.378 (3)
C1—O1	1.366 (3)	C10—F3	1.324 (4)
C1—C2	1.444 (4)	C10—F1	1.332 (3)
C2—C3	1.340 (4)	C10—F2	1.333 (4)
C2—H2	0.9300	C11—O4	1.181 (3)
C3—C4	1.447 (4)	C11—O3	1.368 (3)
C3—C10	1.507 (4)	C11—C12	1.520 (4)
C4—C9	1.391 (4)	C12—C14	1.513 (4)
C4—C5	1.404 (4)	C12—C13	1.529 (4)
C5—C6	1.375 (4)	C13—H13A	0.9600
C5—H5	0.9300	C13—H13B	0.9600
C6—C7	1.385 (4)	C13—H13C	0.9600
C6—H6	0.9300	C14—H14A	0.9600
C7—C8	1.373 (4)	C14—H14B	0.9600
C7—O3	1.400 (3)	C14—H14C	0.9600
C8—C9	1.382 (4)

O2—C1—O1	117.5 (3)	F3—C10—F2	106.4 (3)
O2—C1—C2	125.6 (3)	F1—C10—F2	106.6 (2)
O1—C1—C2	116.9 (2)	F3—C10—C3	111.5 (2)
C3—C2—C1	121.9 (3)	F1—C10—C3	112.1 (3)
C3—C2—H2	119.1	F2—C10—C3	112.4 (2)
C1—C2—H2	119.1	O4—C11—O3	123.6 (2)
C2—C3—C4	120.6 (3)	O4—C11—C12	126.0 (2)
C2—C3—C10	119.4 (3)	O3—C11—C12	110.4 (2)
C4—C3—C10	119.9 (2)	C14—C12—C11	110.2 (2)
C9—C4—C5	117.5 (2)	C14—C12—C13	112.9 (3)
C9—C4—C3	116.5 (2)	C11—C12—C13	114.2 (2)
C5—C4—C3	126.0 (2)	C14—C12—Br1	107.64 (19)
C6—C5—C4	121.1 (2)	C11—C12—Br1	102.84 (17)
C6—C5—H5	119.4	C13—C12—Br1	108.4 (2)
C4—C5—H5	119.4	C12—C13—H13A	109.5
C5—C6—C7	118.8 (2)	C12—C13—H13B	109.5
C5—C6—H6	120.6	H13A—C13—H13B	109.5
C7—C6—H6	120.6	C12—C13—H13C	109.5
C8—C7—C6	122.4 (2)	H13A—C13—H13C	109.5
C8—C7—O3	119.5 (2)	H13B—C13—H13C	109.5
C6—C7—O3	117.8 (2)	C12—C14—H14A	109.5
C7—C8—C9	117.7 (2)	C12—C14—H14B	109.5
C7—C8—H8	121.2	H14A—C14—H14B	109.5
C9—C8—H8	121.2	C12—C14—H14C	109.5
O1—C9—C8	115.6 (2)	H14A—C14—H14C	109.5
O1—C9—C4	121.9 (2)	H14B—C14—H14C	109.5
C8—C9—C4	122.5 (2)	C1—O1—C9	122.1 (2)
F3—C10—F1	107.5 (2)	C11—O3—C7	117.3 (2)

O2—C1—C2—C3	−178.7 (3)	C2—C3—C10—F3	−115.9 (3)
O1—C1—C2—C3	−0.5 (4)	C4—C3—C10—F3	61.5 (3)
C1—C2—C3—C4	−1.1 (4)	C2—C3—C10—F1	4.7 (4)
C1—C2—C3—C10	176.3 (3)	C4—C3—C10—F1	−177.9 (2)
C2—C3—C4—C9	2.8 (4)	C2—C3—C10—F2	124.8 (3)
C10—C3—C4—C9	−174.5 (2)	C4—C3—C10—F2	−57.8 (3)
C2—C3—C4—C5	−177.8 (3)	O4—C11—C12—C14	−20.7 (4)
C10—C3—C4—C5	4.8 (4)	O3—C11—C12—C14	159.3 (2)
C9—C4—C5—C6	1.5 (4)	O4—C11—C12—C13	−149.0 (3)
C3—C4—C5—C6	−177.9 (3)	O3—C11—C12—C13	31.0 (3)
C4—C5—C6—C7	0.2 (4)	O4—C11—C12—Br1	93.8 (3)
C5—C6—C7—C8	−1.6 (4)	O3—C11—C12—Br1	−86.2 (2)
C5—C6—C7—O3	−175.8 (2)	O2—C1—O1—C9	178.6 (3)
C6—C7—C8—C9	1.2 (4)	C2—C1—O1—C9	0.3 (4)
O3—C7—C8—C9	175.3 (2)	C8—C9—O1—C1	−178.9 (2)
C7—C8—C9—O1	−178.8 (2)	C4—C9—O1—C1	1.6 (4)
C7—C8—C9—C4	0.6 (4)	O4—C11—O3—C7	3.3 (4)
C5—C4—C9—O1	177.5 (2)	C12—C11—O3—C7	−176.7 (2)
C3—C4—C9—O1	−3.1 (4)	C8—C7—O3—C11	71.5 (3)
C5—C4—C9—C8	−1.9 (4)	C6—C7—O3—C11	−114.2 (3)
C3—C4—C9—C8	177.5 (2)

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5···F2	0.93	2.47	3.019 (3)	118
C6—H6···O4ⁱ	0.93	2.52	3.261 (4)	136

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

Experimental details

Crystal data
Chemical formula	C₁₄H₁₀BrF₃O₄
M_r	379.13
Crystal system, space group	Triclinic, P1
Temperature (K)	298
a, b, c (Å)	6.1842 (4), 11.0297 (6), 11.0619 (7)
α, β, γ (°)	99.982 (2), 91.797 (2), 104.387 (2)
V (Å³)	717.61 (8)
Z	2
Radiation type	Mo Kα
µ (mm⁻¹)	2.91
Crystal size (mm)	0.40 × 0.26 × 0.24

Data collection
Diffractometer	Bruker APEXII CCD diffractometer
Absorption correction	Multi-scan (SADABS; Bruker, 2004)
T_min, T_max	0.389, 0.542
No. of measured, independent and observed [I > 2σ(I)] reflections	9951, 3796, 2390
R_int	0.022
(sin θ/λ)_max (Å⁻¹)	0.720

Refinement
R[F² > 2σ(F²)], wR(F²), S	0.040, 0.109, 1.01
No. of reflections	3796
No. of parameters	201
H-atom treatment	H-atom parameters constrained
Δρ_max, Δρ_min (e Å⁻³)	0.78, −0.85

Computer programs: APEX2 (Bruker, 2004), SAINT-Plus (Bruker, 2004), SAINT-Plus and XPREP (Bruker, 2004), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), ORTEP-3 (Farrugia, 1997).

Hydrogen-bond geometry (Å, º) top

D—H···A	D—H	H···A	D···A	D—H···A
C5—H5···F2	0.93	2.47	3.019 (3)	118
C6—H6···O4ⁱ	0.93	2.52	3.261 (4)	136

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

Acknowledgements

The authors acknowledge the Department of Chemistry, IIT Madras, for the X-ray data collection.

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