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

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ISSN: 2056-9890

3,6-Di­bromo-7-ethyl­amino-4-methyl-2H-chromen-2-one

aKey Laboratory of Fine Chemical Engineering, Changzhou University, Changzhou 213164, Jiangsu, People's Republic of China
*Correspondence e-mail: xht@cczu.edu.cn

(Received 2 March 2012; accepted 12 March 2012; online 17 March 2012)

In title compound, C12H11Br2NO2, the coumarin ring system is almost planar, the two rings being inclined to one another by 1.40 (15)°. There are two short intra­molecular inter­actions (N—H⋯Br and C—H⋯Br) involving the Br atoms. In the crystal, mol­ecules stack along the a-axis direction via ππ inter­actions; the centroid–centroid distances vary from 3.6484 (19) to 3.7942 (19) Å.

Related literature

For the synthesis of the title compound, see: Belluti et al. (2010[Belluti, F., Fontana, G., Bo, L. D. & Carenini, N. (2010). Bioorg. Med. Chem. 18, 3543-3550.]). For geometrical details of a coumarin compound, see: Kruszynski et al. (2005[Kruszynski, R., Trzesowska, A., Majewski, P., Skretowska, S. & Marszalek, A. (2005). Acta Cryst. E61, o1248-o1250.]).

[Scheme 1]

Experimental

Crystal data
  • C12H11Br2NO2

  • Mr = 361.04

  • Triclinic, [P \overline 1]

  • a = 7.5795 (9) Å

  • b = 7.6839 (9) Å

  • c = 11.2610 (14) Å

  • α = 93.628 (2)°

  • β = 98.288 (3)°

  • γ = 102.626 (3)°

  • V = 630.24 (13) Å3

  • Z = 2

  • Mo Kα radiation

  • μ = 6.42 mm−1

  • T = 293 K

  • 0.20 × 0.18 × 0.15 mm

Data collection
  • Enraf–Nonius CAD-4 diffractometer

  • Absorption correction: ψ scan (North et al., 1968[North, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351-359.]) Tmin = 0.360, Tmax = 0.446

  • 3658 measured reflections

  • 2314 independent reflections

  • 1928 reflections with I > 2σ(I)

  • Rint = 0.023

  • 3 standard reflections every 200 reflections intensity decay 1%

Refinement
  • R[F2 > 2σ(F2)] = 0.031

  • wR(F2) = 0.097

  • S = 1.00

  • 2314 reflections

  • 160 parameters

  • 1 restraint

  • H atoms treated by a mixture of independent and constrained refinement

  • Δρmax = 0.51 e Å−3

  • Δρmin = −0.42 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N1—H1⋯Br1 0.86 (3) 2.67 (3) 3.055 (3) 109 (2)
C10—H10A⋯Br2 0.96 2.68 3.221 (4) 116

Data collection: CAD-4 Software (Enraf–Nonius, 1985[Enraf-Nonius (1985). CAD-4 Software. Enraf-Nonius, Delft, The Netherlands.]); cell refinement: CAD-4 Software; data reduction: XCAD4 (Harms & Wocadlo, 1995[Harms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.]); program(s) used to solve structure: SHELXS97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); program(s) used to refine structure: SHELXL97 (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); molecular graphics: SHELXTL (Sheldrick, 2008[Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.]); software used to prepare material for publication: SHELXTL.

Supporting information


Comment top

The title compound is used as an important intermediate to synthesis fluorescent tracers, for example, it has been recognized as an effective protein tracer (Belluti et al., 2010). Herein we report on the crystal structure of the title compound, which is illustrated in Fig. 1.

The coumarin ring system is almost planar with a dihedral angle involving rings (O2,C1-C5) and (C4-C9) of only 1.40 (2) °. This is normal for such coumarin compounds (Kruszynski et al., 2005). The bromine atoms are involved in short Br···H interactions (Table 1).

In the crystal, the molecules stack along the a axis direction (Fig. 2). There are a number of ππ interactions present: Cg1···Cg1i 3.7580 (19) Å; Cg2···Cg1i 3.6484(19 Å; Cg2···Cg2ii 3.7942 (19) Å [where Cg1 is the centroid of ring (O2,C1-C5); Cg2 is the centroid of ring (C4-C9); symmetry codes: (i) -x+1, -y+1, -z+1; (ii) -x+2, -y+1, -z+1].

Related literature top

For the synthesis of the title compound, see: Belluti et al. (2010). For geometrical details of a coumarin compound, see: Kruszynski et al. (2005).

Experimental top

The title compound was prepared by the method reported by (Belluti et al., 2010). To a suspension of 4-methyl-7-N,N-diethylamino coumarin (5 mmol, 1.61 g) and bromosuccinimide (6 mmol, 1.06 g) in carbon tetrachloride (50 ml), a catalytic amount of benzoyl peroxide was added. The reaction mixture was refluxed for 8 h, then the succinimide produced during the reaction was filtered off. The resulting mixture was washed with water, dried and the solvent was removed under reduced pressure. The pale yellow product obtained was recrystallized from ethanol, yielding colourless block-like crystals of the title compound on evaporating the solvent slowly at room temperature for about 5 days.

Refinement top

The NH H-atom was located in a difference electron-density map and was freely refined. The C-bound H-atoms were included in calculated positions and treated as riding atoms: C-H = 0.93, 0.97 and 0.96 Å for CH, CH2 and CH3 H-atoms, respectively, with Uiso(H) = k × Ueq(parent C-atom), where k = 1.5 for CH3 H-atoms and = 1.2 for other H-atoms.

Structure description top

The title compound is used as an important intermediate to synthesis fluorescent tracers, for example, it has been recognized as an effective protein tracer (Belluti et al., 2010). Herein we report on the crystal structure of the title compound, which is illustrated in Fig. 1.

The coumarin ring system is almost planar with a dihedral angle involving rings (O2,C1-C5) and (C4-C9) of only 1.40 (2) °. This is normal for such coumarin compounds (Kruszynski et al., 2005). The bromine atoms are involved in short Br···H interactions (Table 1).

In the crystal, the molecules stack along the a axis direction (Fig. 2). There are a number of ππ interactions present: Cg1···Cg1i 3.7580 (19) Å; Cg2···Cg1i 3.6484(19 Å; Cg2···Cg2ii 3.7942 (19) Å [where Cg1 is the centroid of ring (O2,C1-C5); Cg2 is the centroid of ring (C4-C9); symmetry codes: (i) -x+1, -y+1, -z+1; (ii) -x+2, -y+1, -z+1].

For the synthesis of the title compound, see: Belluti et al. (2010). For geometrical details of a coumarin compound, see: Kruszynski et al. (2005).

Computing details top

Data collection: CAD-4 Software (Enraf–Nonius, 1985); cell refinement: CAD-4 Software (Enraf–Nonius, 1985); data reduction: XCAD4 (Harms & Wocadlo, 1995); 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).

Figures top
[Figure 1] Fig. 1. The molecular structure of the title molecule, with the atom-numbering scheme. Displacement ellipsoids are drawn at the 50% probability level. The short Br···H interactions are shown as dashed lines.
[Figure 2] Fig. 2. A view along the a axis of the crystal packing of the title compound. The short Br···H interactions are shown as dashed lines.
3,6-Dibromo-7-ethylamino-4-methyl-2H-chromen-2-one top
Crystal data top
C12H11Br2NO2Z = 2
Mr = 361.04F(000) = 352
Triclinic, P1Dx = 1.903 Mg m3
Hall symbol: -P 1Mo Kα radiation, λ = 0.71073 Å
a = 7.5795 (9) ÅCell parameters from 1771 reflections
b = 7.6839 (9) Åθ = 2.7–26.5°
c = 11.2610 (14) ŵ = 6.42 mm1
α = 93.628 (2)°T = 293 K
β = 98.288 (3)°Block, colourless
γ = 102.626 (3)°0.20 × 0.18 × 0.15 mm
V = 630.24 (13) Å3
Data collection top
Enraf–Nonius CAD-4
diffractometer
1928 reflections with I > 2σ(I)
Radiation source: fine-focus sealed tubeRint = 0.023
Graphite monochromatorθmax = 25.5°, θmin = 1.8°
ω/2θ scansh = 98
Absorption correction: ψ scan
(North et al., 1968)
k = 89
Tmin = 0.360, Tmax = 0.446l = 1113
3658 measured reflections3 standard reflections every 200 reflections
2314 independent reflections intensity decay: 1%
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)] = 0.031Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.097H atoms treated by a mixture of independent and constrained refinement
S = 1.00 w = 1/[σ2(Fo2) + (0.0633P)2 + 0.0665P]
where P = (Fo2 + 2Fc2)/3
2314 reflections(Δ/σ)max = 0.001
160 parametersΔρmax = 0.51 e Å3
1 restraintΔρmin = 0.42 e Å3
Crystal data top
C12H11Br2NO2γ = 102.626 (3)°
Mr = 361.04V = 630.24 (13) Å3
Triclinic, P1Z = 2
a = 7.5795 (9) ÅMo Kα radiation
b = 7.6839 (9) ŵ = 6.42 mm1
c = 11.2610 (14) ÅT = 293 K
α = 93.628 (2)°0.20 × 0.18 × 0.15 mm
β = 98.288 (3)°
Data collection top
Enraf–Nonius CAD-4
diffractometer
1928 reflections with I > 2σ(I)
Absorption correction: ψ scan
(North et al., 1968)
Rint = 0.023
Tmin = 0.360, Tmax = 0.4463 standard reflections every 200 reflections
3658 measured reflections intensity decay: 1%
2314 independent reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0311 restraint
wR(F2) = 0.097H atoms treated by a mixture of independent and constrained refinement
S = 1.00Δρmax = 0.51 e Å3
2314 reflectionsΔρmin = 0.42 e Å3
160 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
Br10.93608 (5)0.72412 (5)0.21480 (3)0.05088 (16)
Br20.64459 (6)0.54212 (6)0.87739 (3)0.05501 (16)
O10.5330 (4)0.1746 (4)0.7375 (2)0.0561 (7)
O20.6172 (3)0.2336 (3)0.5627 (2)0.0410 (6)
N10.7998 (4)0.3167 (4)0.1806 (3)0.0403 (7)
C10.6005 (5)0.2886 (5)0.6787 (3)0.0414 (8)
C20.6637 (5)0.4800 (5)0.7146 (3)0.0388 (7)
C30.7310 (4)0.6008 (4)0.6420 (3)0.0358 (7)
C40.7489 (4)0.5355 (4)0.5224 (3)0.0335 (7)
C50.6917 (4)0.3514 (4)0.4864 (3)0.0334 (7)
C60.7056 (4)0.2766 (4)0.3743 (3)0.0352 (7)
H60.66550.15340.35470.042*
C70.7792 (4)0.3845 (4)0.2908 (3)0.0331 (7)
C80.8355 (4)0.5712 (4)0.3261 (3)0.0355 (7)
C90.8197 (4)0.6442 (4)0.4371 (3)0.0358 (7)
H90.85650.76770.45610.043*
C100.7902 (5)0.7994 (5)0.6800 (3)0.0480 (9)
H10A0.75100.82470.75520.072*
H10B0.73610.86320.61950.072*
H10C0.92130.83660.68940.072*
C110.7252 (5)0.1281 (5)0.1345 (3)0.0442 (8)
H11A0.59250.10100.12520.053*
H11B0.76950.05150.19130.053*
C120.7831 (6)0.0925 (6)0.0148 (4)0.0589 (10)
H12A0.91420.11370.02510.088*
H12B0.74200.17090.04050.088*
H12C0.73000.02980.01660.088*
H10.848 (4)0.380 (4)0.128 (2)0.036 (9)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0641 (3)0.0348 (2)0.0574 (3)0.00657 (16)0.02514 (19)0.01385 (16)
Br20.0732 (3)0.0580 (3)0.0363 (2)0.0195 (2)0.01301 (18)0.00175 (17)
O10.0735 (18)0.0491 (16)0.0446 (15)0.0014 (13)0.0231 (13)0.0100 (12)
O20.0551 (14)0.0292 (11)0.0361 (13)0.0006 (10)0.0133 (11)0.0011 (9)
N10.0510 (17)0.0316 (14)0.0416 (16)0.0079 (12)0.0197 (14)0.0049 (12)
C10.0445 (18)0.0410 (19)0.0381 (19)0.0082 (15)0.0064 (15)0.0061 (15)
C20.0437 (18)0.0423 (18)0.0297 (17)0.0106 (14)0.0041 (14)0.0011 (14)
C30.0338 (16)0.0327 (16)0.0396 (18)0.0092 (13)0.0017 (14)0.0031 (13)
C40.0334 (15)0.0308 (16)0.0348 (17)0.0063 (12)0.0039 (13)0.0004 (13)
C50.0351 (16)0.0281 (15)0.0368 (17)0.0067 (12)0.0048 (13)0.0057 (13)
C60.0406 (17)0.0258 (15)0.0386 (18)0.0070 (12)0.0067 (14)0.0013 (13)
C70.0320 (15)0.0285 (15)0.0394 (18)0.0078 (12)0.0072 (13)0.0014 (13)
C80.0366 (16)0.0303 (16)0.0389 (18)0.0045 (12)0.0067 (14)0.0089 (13)
C90.0365 (16)0.0230 (14)0.0457 (19)0.0050 (12)0.0028 (14)0.0016 (13)
C100.056 (2)0.0335 (18)0.050 (2)0.0035 (16)0.0098 (17)0.0084 (16)
C110.051 (2)0.0350 (18)0.045 (2)0.0058 (15)0.0098 (16)0.0020 (15)
C120.077 (3)0.052 (2)0.047 (2)0.013 (2)0.015 (2)0.0055 (18)
Geometric parameters (Å, º) top
Br1—C81.899 (3)C6—C71.390 (5)
Br2—C21.899 (3)C6—H60.9300
O1—C11.200 (4)C7—C81.418 (4)
O2—C51.375 (4)C8—C91.369 (5)
O2—C11.379 (4)C9—H90.9300
N1—C71.358 (4)C10—H10A0.9600
N1—C111.467 (4)C10—H10B0.9600
N1—H10.857 (5)C10—H10C0.9600
C1—C21.455 (5)C11—C121.503 (5)
C2—C31.342 (5)C11—H11A0.9700
C3—C41.443 (5)C11—H11B0.9700
C3—C101.508 (4)C12—H12A0.9600
C4—C91.401 (5)C12—H12B0.9600
C4—C51.401 (4)C12—H12C0.9600
C5—C61.381 (5)
C5—O2—C1122.3 (3)C9—C8—C7122.4 (3)
C7—N1—C11122.7 (3)C9—C8—Br1119.2 (2)
C7—N1—H1124 (2)C7—C8—Br1118.4 (2)
C11—N1—H1113 (2)C8—C9—C4120.9 (3)
O1—C1—O2116.8 (3)C8—C9—H9119.5
O1—C1—C2127.6 (3)C4—C9—H9119.5
O2—C1—C2115.7 (3)C3—C10—H10A109.5
C3—C2—C1124.2 (3)C3—C10—H10B109.5
C3—C2—Br2123.0 (3)H10A—C10—H10B109.5
C1—C2—Br2112.8 (2)C3—C10—H10C109.5
C2—C3—C4117.8 (3)H10A—C10—H10C109.5
C2—C3—C10123.2 (3)H10B—C10—H10C109.5
C4—C3—C10119.0 (3)N1—C11—C12109.7 (3)
C9—C4—C5116.4 (3)N1—C11—H11A109.7
C9—C4—C3124.5 (3)C12—C11—H11A109.7
C5—C4—C3119.0 (3)N1—C11—H11B109.7
O2—C5—C6115.9 (3)C12—C11—H11B109.7
O2—C5—C4121.0 (3)H11A—C11—H11B108.2
C6—C5—C4123.1 (3)C11—C12—H12A109.5
C5—C6—C7120.3 (3)C11—C12—H12B109.5
C5—C6—H6119.9H12A—C12—H12B109.5
C7—C6—H6119.9C11—C12—H12C109.5
N1—C7—C6122.4 (3)H12A—C12—H12C109.5
N1—C7—C8120.7 (3)H12B—C12—H12C109.5
C6—C7—C8116.9 (3)
C5—O2—C1—O1179.8 (3)C9—C4—C5—C61.1 (5)
C5—O2—C1—C21.1 (4)C3—C4—C5—C6179.2 (3)
O1—C1—C2—C3177.1 (4)O2—C5—C6—C7179.9 (3)
O2—C1—C2—C31.5 (5)C4—C5—C6—C70.1 (5)
O1—C1—C2—Br23.8 (5)C11—N1—C7—C68.0 (5)
O2—C1—C2—Br2177.6 (2)C11—N1—C7—C8172.8 (3)
C1—C2—C3—C42.8 (5)C5—C6—C7—N1178.4 (3)
Br2—C2—C3—C4176.3 (2)C5—C6—C7—C80.8 (5)
C1—C2—C3—C10178.0 (3)N1—C7—C8—C9178.9 (3)
Br2—C2—C3—C103.0 (5)C6—C7—C8—C90.2 (5)
C2—C3—C4—C9178.8 (3)N1—C7—C8—Br11.1 (4)
C10—C3—C4—C90.5 (5)C6—C7—C8—Br1179.8 (2)
C2—C3—C4—C51.6 (5)C7—C8—C9—C41.0 (5)
C10—C3—C4—C5179.2 (3)Br1—C8—C9—C4179.0 (2)
C1—O2—C5—C6177.8 (3)C5—C4—C9—C81.7 (5)
C1—O2—C5—C42.2 (5)C3—C4—C9—C8178.7 (3)
C9—C4—C5—O2178.8 (3)C7—N1—C11—C12175.8 (3)
C3—C4—C5—O20.8 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···Br10.86 (3)2.67 (3)3.055 (3)109 (2)
C10—H10A···Br20.962.683.221 (4)116

Experimental details

Crystal data
Chemical formulaC12H11Br2NO2
Mr361.04
Crystal system, space groupTriclinic, P1
Temperature (K)293
a, b, c (Å)7.5795 (9), 7.6839 (9), 11.2610 (14)
α, β, γ (°)93.628 (2), 98.288 (3), 102.626 (3)
V3)630.24 (13)
Z2
Radiation typeMo Kα
µ (mm1)6.42
Crystal size (mm)0.20 × 0.18 × 0.15
Data collection
DiffractometerEnraf–Nonius CAD-4
Absorption correctionψ scan
(North et al., 1968)
Tmin, Tmax0.360, 0.446
No. of measured, independent and
observed [I > 2σ(I)] reflections
3658, 2314, 1928
Rint0.023
(sin θ/λ)max1)0.606
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.031, 0.097, 1.00
No. of reflections2314
No. of parameters160
No. of restraints1
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)0.51, 0.42

Computer programs: CAD-4 Software (Enraf–Nonius, 1985), XCAD4 (Harms & Wocadlo, 1995), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N1—H1···Br10.86 (3)2.67 (3)3.055 (3)109 (2)
C10—H10A···Br20.962.683.221 (4)116
 

Acknowledgements

The authors thank the Center of Testing and Analysis, Nanjing University, for the data collection.

References

First citationBelluti, F., Fontana, G., Bo, L. D. & Carenini, N. (2010). Bioorg. Med. Chem. 18, 3543–3550.  Web of Science CrossRef CAS PubMed Google Scholar
First citationEnraf–Nonius (1985). CAD-4 Software. Enraf–Nonius, Delft, The Netherlands.  Google Scholar
First citationHarms, K. & Wocadlo, S. (1995). XCAD4. University of Marburg, Germany.  Google Scholar
First citationKruszynski, R., Trzesowska, A., Majewski, P., Skretowska, S. & Marszalek, A. (2005). Acta Cryst. E61, o1248–o1250.  Web of Science CSD CrossRef IUCr Journals Google Scholar
First citationNorth, A. C. T., Phillips, D. C. & Mathews, F. S. (1968). Acta Cryst. A24, 351–359.  CrossRef IUCr Journals Web of Science Google Scholar
First citationSheldrick, G. M. (2008). Acta Cryst. A64, 112–122.  Web of Science CrossRef CAS IUCr Journals Google Scholar

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