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

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ISSN: 2056-9890

N-[6-(Di­bromo­meth­yl)-2-pyrid­yl]-2,2-di­methyl­propionamide

aX-ray Crystallography Unit, School of Physics, Universiti Sains Malaysia, 11800 USM, Penang, Malaysia, bCrystal Materials Research Unit, Department of Chemistry, Faculty of Science, Prince of Songkla University, Hat-Yai, Songkhla 90112, Thailand, and cDepartment of Chemistry, Bengal Engineering and Science University, Shibpur, Howrah 711 103, India
*Correspondence e-mail: hkfun@usm.my

(Received 28 February 2009; accepted 4 March 2009; online 11 March 2009)

In the mol­ecular structure of the title compound, C11H14Br2N2O, the dimethyl­propionamide substituent is twisted slightly with respect to the pyridine ring, the inter­planar angle being 12.3 (2)°. The dibromo­methyl group is orientated in such a way that the two Br atoms are tilted away from the pyridine ring. In the crystal structure, mol­ecules are associated into supra­molecular chains by weak C—H⋯O inter­actions. The crystal is further stabilized by weak N—H⋯Br and C—H⋯N inter­actions.

Related literature

For hydrogen-bond motifs, see: Bernstein et al. (1995[Bernstein, J., Davis, R. E., Shimoni, L. & Chang, N.-L. (1995). Angew. Chem. Int. Ed. Engl. 34, 1555-1573.]). For mol­ecular recognition and N-bromo­succinimides, see, for example: Goswami & Mukherjee, (1997[Goswami, S. P. & Mukherjee, R. (1997). Tetrahedron Lett. 38, 1619-1621.]); Goswami et al. (2000[Goswami, S. P., Ghosh, K. & Dasgupta, S. (2000). J. Org. Chem. 65, 1907-1914.], 2001[Goswami, S. P., Ghosh, K., Mukherjee, R., Adak, A. K. & Mahapatra, A. K. (2001). J. Heterocycl. Chem. 38, 173-178.], 2004[Goswami, S. P., Dey, S., Jana, S. & Adak, A. K. (2004). Chem. Lett. 33, 916-917.]). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986[Cosier, J. & Glazer, A. M. (1986). J. Appl. Cryst. 19, 105-107.]).

[Scheme 1]

Experimental

Crystal data
  • C11H14Br2N2O

  • Mr = 350.06

  • Monoclinic, P 21 /c

  • a = 13.2936 (7) Å

  • b = 8.4660 (3) Å

  • c = 11.9638 (6) Å

  • β = 99.195 (3)°

  • V = 1329.15 (11) Å3

  • Z = 4

  • Mo Kα radiation

  • μ = 6.08 mm−1

  • T = 100 K

  • 0.33 × 0.29 × 0.24 mm

Data collection
  • Bruker APEXII CCD area-detector diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.114, Tmax = 0.233

  • 12087 measured reflections

  • 3863 independent reflections

  • 2954 reflections with I > 2σ(I)

  • Rint = 0.039

Refinement
  • R[F2 > 2σ(F2)] = 0.051

  • wR(F2) = 0.153

  • S = 1.10

  • 3863 reflections

  • 152 parameters

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

  • Δρmax = 1.98 e Å−3

  • Δρmin = −1.13 e Å−3

Table 1
Hydrogen-bond geometry (Å, °)

D—H⋯A D—H H⋯A DA D—H⋯A
N2—H1N2⋯Br1i 0.82 (5) 2.89 (4) 3.587 (4) 144 (4)
C3—H3A⋯O1ii 0.93 2.41 3.249 (5) 151
C4—H4A⋯O1 0.93 2.34 2.886 (5) 117
C9—H9B⋯N1iii 0.96 2.55 3.506 (6) 179
Symmetry codes: (i) [-x, y+{\script{1\over 2}}, -z+{\script{3\over 2}}]; (ii) [-x+1, y-{\script{1\over 2}}, -z+{\script{3\over 2}}]; (iii) [x, -y+{\script{3\over 2}}, z-{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2005[Bruker (2005). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; 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 and PLATON (Spek, 2009[Spek, A. L. (2009). Acta Cryst. D65, 148-155.]).

Supporting information


Comment top

Bromomethyl aromatic and heteroaromatic compounds (e.g. pyridine or naphthyridine derivatives) are important substrates and they have been used as the precursors for pharmacologically active compounds. Bromide compounds have applications in the synthesis of artificial receptors for molecular recognition research (Goswami & Mukherjee, 1997; Goswami et al., 2000). We have also reported the N-bromosuccinimide reaction of various heterocycles in the absence or presence of water (Goswami et al., 2001; 2004). We report here the crystal structure of the title compound which is a side-chain substituted with gem-dibromo moiety of pyridine.

In Fig. 1, the O1, N2, C6, C7 atoms lie on the same plane with the maximum deviation of 0.005 (5) Å being for atom C6. The mean plane through these atoms makes the dihedral angle of 12.3 (2)° with the mean plane through pyridine ring. This dihedral angle and the torsion angles C6–N2–C5–C4 = -14.4 (7)°, C5–N2–C6–O1 = 5.2 (7)° and C5–N2–C6–C7 = -174.0 (4)° indicate the orientation of the dimethylpropionamide substituent is slightly twisted with respect to the pyridine ring. The dibromomethyl group on the pyridine ring is orientated in such a way that the two bromine atoms are tilted away from the plane of pyridine ring. A weak intramolecular C4–H4A···O1 contact generates a S(6) ring motif (Bernstein et al., 1995).

The crystal packing shows that the molecules are associated into supramolecular chains via weak C—H···O interactions (Table 1). The crystal is further stabilized by weak interactions of the type N—H···Br and C—H···N (Table 1).

Related literature top

For hydrogen-bond motifs, see: Bernstein et al. (1995). For molecular recognition and N-bromosuccinimides, see, for example: Goswami & Mukherjee, (1997); Goswami et al. (2000, 2001, 2004). For the stability of the temperature controller used in the data collection, see: Cosier & Glazer (1986).

Experimental top

To a 100 ml round bottom flask, a mixture of compound 1 (see Fig. 3) (3 g, 0.016 mol) and azobisisobutyronitrile (AIBN) (1.28 g, 7.79 mmol) were added. Dry CCl4 (30 ml) was added and the reaction mixture was heated to reflux for 30 min with vigorous stirring in the presence of light from a 60 W lamp. When all the materials were dissolved, N-bromosuccinimide (NBS) (2.78 g, 0.016 mol) was added slowly and reflux continued for 3 h. The reaction mixture was cooled, crushed ice added, and then extracted with CCl4 to afford the crude product. The brown liquid was purified by column chromatography over 100–200 mesh silica gel using 3% ethylacetate in petroleum ether (330–350 K) as eluent to yield a white dense liquid of compound 2 (Fig. 3) (2.12 g, yield 50%) and a crystalline solid 3 (2.18 g, yield 40%).

Refinement top

The amide-H atom was located in a difference map and refined isotropically; N-H = 0.82 (5)Å. The remaining H atoms were constrained in a riding motion approximation with d(C—H) = 0.93 Å and Uiso=1.2Ueq(C) for aromatic-H, d(C—H) = 0.98 Å and Uiso=1.2Ueq(C) for methine-H, and d(C—H) = 0.96 Å and Uiso=1.5Ueq(C) for methyl-H. A rotating group model was used for the methyl groups. The highest residual electron density peak was located at 0.86 Å from Br1 and the deepest hole was located at 0.86 Å from Br2.

Computing details top

Data collection: APEX2 (Bruker, 2005); cell refinement: SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); 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) and PLATON (Spek, 2009).

Figures top
[Figure 1] Fig. 1. The molecular structure of (I), showing 50% probability displacement ellipsoids and the atomic numbering. The intramolecular C-H···O contact is drawn as a dashed line.
[Figure 2] Fig. 2. The crystal packing of the title compound, viewed down the c axis showing dimers with R22(6) motifs. Hydrogen bonds were drawn as dashed lines.
N-[6-(Dibromomethyl)-2-pyridyl]-2,2-dimethylpropionamide top
Crystal data top
C11H14Br2N2OF(000) = 688
Mr = 350.06Dx = 1.749 Mg m3
Monoclinic, P21/cMo Kα radiation, λ = 0.71073 Å
Hall symbol: -P 2ybcCell parameters from 3863 reflections
a = 13.2936 (7) Åθ = 1.6–30.0°
b = 8.4660 (3) ŵ = 6.08 mm1
c = 11.9638 (6) ÅT = 100 K
β = 99.195 (3)°Block, colorless
V = 1329.15 (11) Å30.33 × 0.29 × 0.24 mm
Z = 4
Data collection top
Bruker APEXII CCD area-detector
diffractometer
3863 independent reflections
Radiation source: sealed tube2954 reflections with I > 2σ(I)
Graphite monochromatorRint = 0.039
ϕ and ω scansθmax = 30.0°, θmin = 1.6°
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
h = 1618
Tmin = 0.114, Tmax = 0.233k = 911
12087 measured reflectionsl = 1616
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)] = 0.051Hydrogen site location: inferred from neighbouring sites
wR(F2) = 0.153H atoms treated by a mixture of independent and constrained refinement
S = 1.10 w = 1/[σ2(Fo2) + (0.0946P)2]
where P = (Fo2 + 2Fc2)/3
3863 reflections(Δ/σ)max < 0.001
152 parametersΔρmax = 1.98 e Å3
0 restraintsΔρmin = 1.13 e Å3
Crystal data top
C11H14Br2N2OV = 1329.15 (11) Å3
Mr = 350.06Z = 4
Monoclinic, P21/cMo Kα radiation
a = 13.2936 (7) ŵ = 6.08 mm1
b = 8.4660 (3) ÅT = 100 K
c = 11.9638 (6) Å0.33 × 0.29 × 0.24 mm
β = 99.195 (3)°
Data collection top
Bruker APEXII CCD area-detector
diffractometer
3863 independent reflections
Absorption correction: multi-scan
(SADABS; Bruker, 2005)
2954 reflections with I > 2σ(I)
Tmin = 0.114, Tmax = 0.233Rint = 0.039
12087 measured reflections
Refinement top
R[F2 > 2σ(F2)] = 0.0510 restraints
wR(F2) = 0.153H atoms treated by a mixture of independent and constrained refinement
S = 1.10Δρmax = 1.98 e Å3
3863 reflectionsΔρmin = 1.13 e Å3
152 parameters
Special details top

Experimental. The crystal was placed in the cold stream of an Oxford Cryosystems Cobra open-flow nitrogen cryostat (Cosier & Glazer, 1986) operating at 100.0 (1) K.

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
Br10.01634 (3)0.15918 (5)0.82585 (4)0.02738 (15)
Br20.08741 (3)0.31287 (5)1.05799 (4)0.02696 (15)
O10.4376 (2)0.5484 (4)0.6250 (3)0.0403 (9)
N10.1855 (2)0.4274 (4)0.7746 (3)0.0188 (6)
N20.2728 (3)0.5490 (4)0.6511 (3)0.0233 (7)
C10.1747 (3)0.3175 (4)0.8522 (4)0.0205 (8)
C20.2499 (3)0.2067 (5)0.8910 (4)0.0250 (9)
H2A0.24160.13450.94740.030*
C30.3376 (3)0.2089 (5)0.8420 (4)0.0269 (9)
H3A0.38870.13510.86430.032*
C40.3500 (3)0.3196 (4)0.7602 (4)0.0230 (8)
H4A0.40840.32160.72670.028*
C50.2719 (3)0.4275 (5)0.7302 (3)0.0191 (7)
C60.3540 (3)0.6069 (5)0.6056 (4)0.0237 (8)
C70.3295 (3)0.7544 (5)0.5291 (4)0.0278 (9)
C80.3325 (5)0.8986 (6)0.6075 (5)0.0463 (13)
H8A0.39620.90010.65840.070*
H8B0.27740.89230.65020.070*
H8C0.32600.99330.56290.070*
C90.2253 (4)0.7427 (6)0.4534 (5)0.0441 (14)
H9A0.22270.64840.40840.066*
H9B0.21520.83320.40450.066*
H9C0.17270.73910.49980.066*
C100.4117 (4)0.7706 (7)0.4552 (5)0.0452 (14)
H10A0.41500.67530.41240.068*
H10B0.47630.78870.50220.068*
H10C0.39590.85790.40430.068*
C110.0748 (3)0.3265 (4)0.8950 (3)0.0212 (8)
H11A0.04330.42830.87130.025*
H1N20.224 (3)0.609 (6)0.638 (4)0.023 (12)*
Atomic displacement parameters (Å2) top
U11U22U33U12U13U23
Br10.0269 (2)0.0317 (3)0.0252 (2)0.00904 (17)0.00912 (17)0.00740 (16)
Br20.0314 (3)0.0321 (3)0.0176 (2)0.00285 (17)0.00477 (17)0.00017 (15)
O10.0224 (16)0.0365 (19)0.064 (3)0.0035 (14)0.0128 (16)0.0234 (17)
N10.0202 (16)0.0166 (15)0.0189 (15)0.0010 (12)0.0012 (13)0.0006 (12)
N20.0215 (17)0.0221 (17)0.0271 (18)0.0045 (14)0.0064 (14)0.0044 (14)
C10.0213 (19)0.0155 (18)0.025 (2)0.0025 (14)0.0030 (16)0.0011 (14)
C20.027 (2)0.0176 (18)0.031 (2)0.0014 (15)0.0064 (17)0.0041 (16)
C30.026 (2)0.0172 (19)0.037 (2)0.0033 (16)0.0029 (18)0.0031 (17)
C40.0197 (19)0.0169 (19)0.033 (2)0.0014 (14)0.0070 (17)0.0001 (15)
C50.0186 (18)0.0168 (18)0.0219 (18)0.0021 (14)0.0031 (15)0.0005 (14)
C60.0211 (19)0.0207 (19)0.030 (2)0.0017 (15)0.0057 (16)0.0011 (16)
C70.027 (2)0.024 (2)0.034 (2)0.0004 (17)0.0103 (18)0.0048 (17)
C80.065 (4)0.022 (2)0.053 (3)0.003 (2)0.010 (3)0.000 (2)
C90.043 (3)0.035 (3)0.051 (3)0.003 (2)0.004 (2)0.025 (2)
C100.046 (3)0.043 (3)0.052 (3)0.012 (2)0.023 (3)0.022 (3)
C110.024 (2)0.0194 (19)0.0206 (19)0.0010 (15)0.0044 (15)0.0021 (14)
Geometric parameters (Å, º) top
Br1—C111.959 (4)C4—H4A0.9300
Br2—C111.934 (4)C6—C71.551 (6)
O1—C61.205 (5)C7—C101.518 (6)
N1—C11.338 (5)C7—C91.532 (7)
N1—C51.341 (5)C7—C81.536 (7)
N2—C61.374 (5)C8—H8A0.9600
N2—C51.400 (5)C8—H8B0.9600
N2—H1N20.82 (5)C8—H8C0.9600
C1—C21.395 (6)C9—H9A0.9600
C1—C111.500 (6)C9—H9B0.9600
C2—C31.386 (6)C9—H9C0.9600
C2—H2A0.9300C10—H10A0.9600
C3—C41.384 (6)C10—H10B0.9600
C3—H3A0.9300C10—H10C0.9600
C4—C51.385 (5)C11—H11A0.9800
C1—N1—C5117.9 (3)C9—C7—C6112.4 (4)
C6—N2—C5128.5 (4)C8—C7—C6107.2 (4)
C6—N2—H1N2110 (3)C7—C8—H8A109.5
C5—N2—H1N2120 (3)C7—C8—H8B109.5
N1—C1—C2123.2 (4)H8A—C8—H8B109.5
N1—C1—C11113.6 (3)C7—C8—H8C109.5
C2—C1—C11123.2 (4)H8A—C8—H8C109.5
C3—C2—C1117.2 (4)H8B—C8—H8C109.5
C3—C2—H2A121.4C7—C9—H9A109.5
C1—C2—H2A121.4C7—C9—H9B109.5
C4—C3—C2120.7 (4)H9A—C9—H9B109.5
C4—C3—H3A119.6C7—C9—H9C109.5
C2—C3—H3A119.6H9A—C9—H9C109.5
C3—C4—C5117.5 (4)H9B—C9—H9C109.5
C3—C4—H4A121.3C7—C10—H10A109.5
C5—C4—H4A121.3C7—C10—H10B109.5
N1—C5—C4123.4 (4)H10A—C10—H10B109.5
N1—C5—N2111.6 (3)C7—C10—H10C109.5
C4—C5—N2124.9 (4)H10A—C10—H10C109.5
O1—C6—N2122.4 (4)H10B—C10—H10C109.5
O1—C6—C7123.0 (4)C1—C11—Br2113.7 (3)
N2—C6—C7114.6 (3)C1—C11—Br1110.0 (3)
C10—C7—C9109.2 (4)Br2—C11—Br1109.32 (19)
C10—C7—C8109.4 (4)C1—C11—H11A107.9
C9—C7—C8110.2 (4)Br2—C11—H11A107.9
C10—C7—C6108.2 (4)Br1—C11—H11A107.9
C5—N1—C1—C21.9 (6)C5—N2—C6—O15.2 (7)
C5—N1—C1—C11179.1 (3)C5—N2—C6—C7174.0 (4)
N1—C1—C2—C32.8 (6)O1—C6—C7—C1019.8 (6)
C11—C1—C2—C3178.3 (4)N2—C6—C7—C10161.0 (4)
C1—C2—C3—C41.6 (7)O1—C6—C7—C9140.5 (5)
C2—C3—C4—C50.3 (7)N2—C6—C7—C940.3 (6)
C1—N1—C5—C40.3 (6)O1—C6—C7—C898.2 (5)
C1—N1—C5—N2179.7 (3)N2—C6—C7—C881.0 (5)
C3—C4—C5—N11.3 (6)N1—C1—C11—Br2133.6 (3)
C3—C4—C5—N2178.6 (4)C2—C1—C11—Br245.5 (5)
C6—N2—C5—N1165.5 (4)N1—C1—C11—Br1103.5 (3)
C6—N2—C5—C414.4 (7)C2—C1—C11—Br177.5 (5)
Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H1N2···Br1i0.82 (5)2.89 (4)3.587 (4)144 (4)
C3—H3A···O1ii0.932.413.249 (5)151
C4—H4A···O10.932.342.886 (5)117
C9—H9B···N1iii0.962.553.506 (6)179
Symmetry codes: (i) x, y+1/2, z+3/2; (ii) x+1, y1/2, z+3/2; (iii) x, y+3/2, z1/2.

Experimental details

Crystal data
Chemical formulaC11H14Br2N2O
Mr350.06
Crystal system, space groupMonoclinic, P21/c
Temperature (K)100
a, b, c (Å)13.2936 (7), 8.4660 (3), 11.9638 (6)
β (°) 99.195 (3)
V3)1329.15 (11)
Z4
Radiation typeMo Kα
µ (mm1)6.08
Crystal size (mm)0.33 × 0.29 × 0.24
Data collection
DiffractometerBruker APEXII CCD area-detector
diffractometer
Absorption correctionMulti-scan
(SADABS; Bruker, 2005)
Tmin, Tmax0.114, 0.233
No. of measured, independent and
observed [I > 2σ(I)] reflections
12087, 3863, 2954
Rint0.039
(sin θ/λ)max1)0.703
Refinement
R[F2 > 2σ(F2)], wR(F2), S 0.051, 0.153, 1.10
No. of reflections3863
No. of parameters152
H-atom treatmentH atoms treated by a mixture of independent and constrained refinement
Δρmax, Δρmin (e Å3)1.98, 1.13

Computer programs: APEX2 (Bruker, 2005), SAINT (Bruker, 2005), SHELXTL (Sheldrick, 2008) and PLATON (Spek, 2009).

Hydrogen-bond geometry (Å, º) top
D—H···AD—HH···AD···AD—H···A
N2—H1N2···Br1i0.82 (5)2.89 (4)3.587 (4)144 (4)
C3—H3A···O1ii0.932.413.249 (5)151
C4—H4A···O10.932.342.886 (5)117
C9—H9B···N1iii0.962.553.506 (6)179
Symmetry codes: (i) x, y+1/2, z+3/2; (ii) x+1, y1/2, z+3/2; (iii) x, y+3/2, z1/2.
 

Footnotes

Additional correspondence author, e-mail: suchada.c@psu.ac.th.

Acknowledgements

ACM, RC and SG thank the DST [SR/S1/OC-13/2005], Government of India, for financial support. ACM thanks the UGC, Government of India, for a fellowship. The authors also thank Universiti Sains Malaysia for the Research University Golden Goose grant No. 1001/PFIZIK/811012.

References

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