organic compounds
5-Bromo-N3-phenylpyrazine-2,3-diamine
aSchool of Chemistry and Chemical Engineering, Taishan Medical University, Tai'an 271016, People's Republic of China
*Correspondence e-mail: zhuxh007@163.com
In the title compound, C10H9BrN4, the dihedral angle between the benzene and pyrazine rings is 61.34 (5)°. Intermolecular N—H⋯N hydrogen bonds and N—H⋯π interactions assemble the molecules into a three-dimensional network structure.
Related literature
For Cu or Pd catalysed C–N cross-coupling reactions, see: Fors et al. (2009); Liu et al. (2007).
Experimental
Crystal data
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Refinement
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Data collection: SMART (Bruker, 2005); cell SAINT (Bruker, 2005); data reduction: SAINT; 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: SHELXL97.
Supporting information
10.1107/S1600536809028554/gk2218sup1.cif
contains datablocks I, global. DOI:Structure factors: contains datablock I. DOI: 10.1107/S1600536809028554/gk2218Isup2.hkl
5-Bromo-2-aminopyrazine (10 mmol) and aniline (40 mmol) were added to a reaction kettle, then reacted 2 h at 413 K under microwave operation. The product was purified on a SiO2 flash column to give a title product (yield 31%). Crystals of the title compound suitable for X-ray analysis were grown from a dichloromethane solution.
The C–H and N–H hydrogen atoms were placed in calculated positions, with distances C—H = 0.93 Å, N—H = 0.87 Å. and Uiso(H) = 1.2 Ueq (C, N). Initially positions of the amino H atoms were refined but in the final cycles the N—H distances were constrained to 0.87 Å and all H atoms were treated as riding with Uiso(H) values of 1.5Ueq(C,N).
Data collection: SMART (Bruker, 2005); cell
SAINT (Bruker, 2005); data reduction: SAINT (Bruker, 2005); 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: SHELXL97 (Sheldrick, 2008).C10H9BrN4 | F(000) = 528 |
Mr = 265.12 | Dx = 1.660 Mg m−3 |
Monoclinic, P21/c | Mo Kα radiation, λ = 0.71073 Å |
Hall symbol: -P 2ybc | Cell parameters from 2474 reflections |
a = 7.4834 (8) Å | θ = 2.6–27.6° |
b = 15.4038 (17) Å | µ = 3.85 mm−1 |
c = 9.2079 (10) Å | T = 293 K |
β = 91.307 (2)° | Block, colorless |
V = 1061.1 (2) Å3 | 0.15 × 0.12 × 0.10 mm |
Z = 4 |
Bruker SMART APEX diffractometer | 1871 independent reflections |
Radiation source: fine-focus sealed tube | 1555 reflections with I > 2σ(I) |
Graphite monochromator | Rint = 0.022 |
ϕ and ω scans | θmax = 25.0°, θmin = 2.6° |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | h = −8→8 |
Tmin = 0.596, Tmax = 0.700 | k = −17→18 |
5494 measured reflections | l = −10→10 |
Refinement on F2 | Secondary atom site location: difference Fourier map |
Least-squares matrix: full | Hydrogen site location: inferred from neighbouring sites |
R[F2 > 2σ(F2)] = 0.025 | H-atom parameters constrained |
wR(F2) = 0.059 | w = 1/[σ2(Fo2) + (0.025P)2 + 0.6504P] where P = (Fo2 + 2Fc2)/3 |
S = 1.00 | (Δ/σ)max = 0.002 |
1871 reflections | Δρmax = 0.33 e Å−3 |
140 parameters | Δρmin = −0.33 e Å−3 |
0 restraints | Extinction correction: SHELXL97 (Sheldrick, 2008), Fc*=kFc[1+0.001xFc2λ3/sin(2θ)]-1/4 |
Primary atom site location: structure-invariant direct methods | Extinction coefficient: 0.0241 (11) |
C10H9BrN4 | V = 1061.1 (2) Å3 |
Mr = 265.12 | Z = 4 |
Monoclinic, P21/c | Mo Kα radiation |
a = 7.4834 (8) Å | µ = 3.85 mm−1 |
b = 15.4038 (17) Å | T = 293 K |
c = 9.2079 (10) Å | 0.15 × 0.12 × 0.10 mm |
β = 91.307 (2)° |
Bruker SMART APEX diffractometer | 1871 independent reflections |
Absorption correction: multi-scan (SADABS; Bruker, 2005) | 1555 reflections with I > 2σ(I) |
Tmin = 0.596, Tmax = 0.700 | Rint = 0.022 |
5494 measured reflections |
R[F2 > 2σ(F2)] = 0.025 | 0 restraints |
wR(F2) = 0.059 | H-atom parameters constrained |
S = 1.00 | Δρmax = 0.33 e Å−3 |
1871 reflections | Δρmin = −0.33 e Å−3 |
140 parameters |
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. |
x | y | z | Uiso*/Ueq | ||
Br1 | −0.05901 (4) | 0.351301 (18) | 1.09071 (3) | 0.05020 (14) | |
N1 | 0.1466 (3) | 0.39455 (14) | 0.4791 (2) | 0.0455 (5) | |
H1A | 0.1000 | 0.4388 | 0.4334 | 0.046 (8)* | |
H1B | 0.2400 | 0.3676 | 0.4472 | 0.075 (11)* | |
N2 | −0.0254 (3) | 0.43567 (13) | 0.6710 (2) | 0.0404 (5) | |
N3 | 0.1484 (2) | 0.31467 (12) | 0.84959 (19) | 0.0319 (4) | |
N4 | 0.3193 (3) | 0.27272 (13) | 0.6497 (2) | 0.0420 (5) | |
H4 | 0.2980 | 0.2595 | 0.5591 | 0.063 (9)* | |
C1 | 0.1017 (3) | 0.38587 (14) | 0.6195 (2) | 0.0317 (5) | |
C2 | 0.1899 (3) | 0.32331 (14) | 0.7117 (2) | 0.0302 (5) | |
C3 | 0.0152 (3) | 0.36556 (15) | 0.8955 (2) | 0.0343 (5) | |
C4 | −0.0699 (3) | 0.42447 (16) | 0.8104 (3) | 0.0423 (6) | |
H4A | −0.1608 | 0.4579 | 0.8488 | 0.051* | |
C5 | 0.4259 (3) | 0.21097 (15) | 0.7267 (2) | 0.0365 (6) | |
C6 | 0.4269 (4) | 0.12553 (16) | 0.6809 (3) | 0.0446 (6) | |
H6 | 0.3565 | 0.1084 | 0.6014 | 0.054* | |
C7 | 0.5329 (4) | 0.06590 (19) | 0.7538 (3) | 0.0564 (8) | |
H7 | 0.5338 | 0.0084 | 0.7229 | 0.068* | |
C8 | 0.6367 (4) | 0.0902 (2) | 0.8710 (3) | 0.0613 (8) | |
H8 | 0.7056 | 0.0491 | 0.9209 | 0.074* | |
C9 | 0.6390 (4) | 0.1748 (2) | 0.9145 (3) | 0.0589 (8) | |
H9 | 0.7108 | 0.1916 | 0.9934 | 0.071* | |
C10 | 0.5348 (3) | 0.23602 (18) | 0.8419 (3) | 0.0468 (6) | |
H10 | 0.5383 | 0.2938 | 0.8709 | 0.056* |
U11 | U22 | U33 | U12 | U13 | U23 | |
Br1 | 0.0541 (2) | 0.0615 (2) | 0.03565 (17) | 0.00683 (14) | 0.01461 (11) | 0.00123 (12) |
N1 | 0.0648 (15) | 0.0406 (12) | 0.0314 (11) | 0.0182 (11) | 0.0047 (10) | 0.0082 (9) |
N2 | 0.0466 (13) | 0.0353 (11) | 0.0392 (12) | 0.0102 (9) | 0.0014 (9) | 0.0047 (9) |
N3 | 0.0345 (11) | 0.0327 (10) | 0.0288 (10) | 0.0035 (8) | 0.0036 (8) | 0.0018 (8) |
N4 | 0.0504 (13) | 0.0451 (12) | 0.0310 (11) | 0.0194 (10) | 0.0094 (9) | 0.0070 (9) |
C1 | 0.0369 (13) | 0.0262 (11) | 0.0320 (12) | 0.0014 (10) | −0.0003 (10) | −0.0008 (9) |
C2 | 0.0330 (13) | 0.0265 (11) | 0.0312 (12) | 0.0008 (9) | 0.0013 (10) | 0.0001 (9) |
C3 | 0.0375 (13) | 0.0359 (13) | 0.0297 (12) | −0.0004 (10) | 0.0048 (10) | −0.0004 (10) |
C4 | 0.0433 (15) | 0.0400 (14) | 0.0440 (15) | 0.0124 (11) | 0.0085 (11) | 0.0005 (11) |
C5 | 0.0339 (13) | 0.0404 (14) | 0.0356 (12) | 0.0084 (10) | 0.0107 (10) | 0.0087 (11) |
C6 | 0.0408 (15) | 0.0416 (15) | 0.0516 (16) | 0.0068 (11) | 0.0040 (12) | 0.0028 (12) |
C7 | 0.0502 (17) | 0.0404 (15) | 0.079 (2) | 0.0149 (13) | 0.0099 (15) | 0.0084 (14) |
C8 | 0.0492 (18) | 0.069 (2) | 0.066 (2) | 0.0229 (15) | 0.0049 (15) | 0.0211 (16) |
C9 | 0.0419 (16) | 0.084 (2) | 0.0504 (17) | 0.0121 (15) | −0.0041 (13) | 0.0015 (15) |
C10 | 0.0438 (15) | 0.0478 (15) | 0.0489 (15) | 0.0067 (12) | 0.0064 (12) | −0.0016 (13) |
Br1—C3 | 1.906 (2) | C4—H4A | 0.9300 |
N1—C1 | 1.349 (3) | C5—C10 | 1.378 (4) |
N1—H1A | 0.8699 | C5—C6 | 1.382 (3) |
N1—H1B | 0.8700 | C6—C7 | 1.378 (4) |
N2—C1 | 1.319 (3) | C6—H6 | 0.9300 |
N2—C4 | 1.344 (3) | C7—C8 | 1.368 (4) |
N3—C2 | 1.320 (3) | C7—H7 | 0.9300 |
N3—C3 | 1.344 (3) | C8—C9 | 1.364 (4) |
N4—C2 | 1.377 (3) | C8—H8 | 0.9300 |
N4—C5 | 1.420 (3) | C9—C10 | 1.385 (4) |
N4—H4 | 0.8700 | C9—H9 | 0.9300 |
C1—C2 | 1.436 (3) | C10—H10 | 0.9300 |
C3—C4 | 1.349 (3) | ||
C1—N1—H1A | 115.8 | C3—C4—H4A | 119.4 |
C1—N1—H1B | 119.8 | C10—C5—C6 | 119.6 (2) |
H1A—N1—H1B | 121.8 | C10—C5—N4 | 120.8 (2) |
C1—N2—C4 | 117.7 (2) | C6—C5—N4 | 119.5 (2) |
C2—N3—C3 | 115.85 (19) | C7—C6—C5 | 119.5 (3) |
C2—N4—C5 | 124.36 (19) | C7—C6—H6 | 120.2 |
C2—N4—H4 | 114.5 | C5—C6—H6 | 120.2 |
C5—N4—H4 | 114.3 | C8—C7—C6 | 120.8 (3) |
N2—C1—N1 | 119.0 (2) | C8—C7—H7 | 119.6 |
N2—C1—C2 | 120.2 (2) | C6—C7—H7 | 119.6 |
N1—C1—C2 | 120.8 (2) | C9—C8—C7 | 119.7 (3) |
N3—C2—N4 | 121.6 (2) | C9—C8—H8 | 120.1 |
N3—C2—C1 | 121.5 (2) | C7—C8—H8 | 120.1 |
N4—C2—C1 | 116.92 (19) | C8—C9—C10 | 120.4 (3) |
N3—C3—C4 | 123.6 (2) | C8—C9—H9 | 119.8 |
N3—C3—Br1 | 117.62 (16) | C10—C9—H9 | 119.8 |
C4—C3—Br1 | 118.81 (18) | C5—C10—C9 | 119.8 (3) |
N2—C4—C3 | 121.2 (2) | C5—C10—H10 | 120.1 |
N2—C4—H4A | 119.4 | C9—C10—H10 | 120.1 |
C4—N2—C1—N1 | 178.7 (2) | N3—C3—C4—N2 | 0.3 (4) |
C4—N2—C1—C2 | −1.1 (3) | Br1—C3—C4—N2 | −178.49 (19) |
C3—N3—C2—N4 | −177.5 (2) | C2—N4—C5—C10 | −59.7 (3) |
C3—N3—C2—C1 | 2.3 (3) | C2—N4—C5—C6 | 123.5 (3) |
C5—N4—C2—N3 | −3.5 (4) | C10—C5—C6—C7 | 1.9 (4) |
C5—N4—C2—C1 | 176.6 (2) | N4—C5—C6—C7 | 178.8 (2) |
N2—C1—C2—N3 | −0.9 (3) | C5—C6—C7—C8 | 0.1 (4) |
N1—C1—C2—N3 | 179.4 (2) | C6—C7—C8—C9 | −1.6 (5) |
N2—C1—C2—N4 | 179.0 (2) | C7—C8—C9—C10 | 0.9 (5) |
N1—C1—C2—N4 | −0.8 (3) | C6—C5—C10—C9 | −2.6 (4) |
C2—N3—C3—C4 | −2.1 (3) | N4—C5—C10—C9 | −179.4 (2) |
C2—N3—C3—Br1 | 176.66 (16) | C8—C9—C10—C5 | 1.2 (4) |
C1—N2—C4—C3 | 1.3 (4) |
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1B···Cg1i | 0.86 | 2.63 | 3.436 (3) | 157 |
N1—H1A···N2ii | 0.86 | 2.22 | 3.084 (3) | 169 |
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) −x, −y+1, −z+1. |
Experimental details
Crystal data | |
Chemical formula | C10H9BrN4 |
Mr | 265.12 |
Crystal system, space group | Monoclinic, P21/c |
Temperature (K) | 293 |
a, b, c (Å) | 7.4834 (8), 15.4038 (17), 9.2079 (10) |
β (°) | 91.307 (2) |
V (Å3) | 1061.1 (2) |
Z | 4 |
Radiation type | Mo Kα |
µ (mm−1) | 3.85 |
Crystal size (mm) | 0.15 × 0.12 × 0.10 |
Data collection | |
Diffractometer | Bruker SMART APEX diffractometer |
Absorption correction | Multi-scan (SADABS; Bruker, 2005) |
Tmin, Tmax | 0.596, 0.700 |
No. of measured, independent and observed [I > 2σ(I)] reflections | 5494, 1871, 1555 |
Rint | 0.022 |
(sin θ/λ)max (Å−1) | 0.595 |
Refinement | |
R[F2 > 2σ(F2)], wR(F2), S | 0.025, 0.059, 1.00 |
No. of reflections | 1871 |
No. of parameters | 140 |
H-atom treatment | H-atom parameters constrained |
Δρmax, Δρmin (e Å−3) | 0.33, −0.33 |
Computer programs: SMART (Bruker, 2005), SAINT (Bruker, 2005), SHELXS97 (Sheldrick, 2008), SHELXL97 (Sheldrick, 2008), SHELXTL (Sheldrick, 2008).
D—H···A | D—H | H···A | D···A | D—H···A |
N1—H1B···Cg1i | 0.86 | 2.63 | 3.436 (3) | 157 |
N1—H1A···N2ii | 0.86 | 2.22 | 3.084 (3) | 169 |
Symmetry codes: (i) x, −y+1/2, z−1/2; (ii) −x, −y+1, −z+1. |
References
Bruker (2005). SMART, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA. Google Scholar
Fors, B. P., Davis, N. R. & Buchwald, S. L. (2009). J. Am. Chem. Soc. 131, 5766–5768. Web of Science CrossRef PubMed CAS Google Scholar
Liu, Y. F., Bai, Y. J., Zhang, J., Li, Y. Y., Jiao, J. P. & Qi, X. L. (2007). Eur. J. Org. Chem., 6084–6088. Google Scholar
Sheldrick, G. M. (2008). Acta Cryst. A64, 112–122. Web of Science CrossRef CAS IUCr Journals Google Scholar
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Cu or Pd catalyzed C—N cross-coupling reactions were studied recently (Liu et al., 2007; Fors et al., 2009), which reported that catalysts using certain ligands allow for the C—N cross-coupling reactions. Different to them, we got a cross-coupling product with high selectivity under microwave without catalyst.
Here we report the crystal structure of the title compound. In (I) (Fig.1), the bond length to the bridging NH group are 1.377 (3) and 1.420 (3) Å. Moreover, intermolecular typical N—H···N (N···N 3.084 (3) Å) hydrogen bonds and N—H···π [H···π 2.633 (2) Å] interaction assemble molecules into a two-dimensional network structure.