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Volume 69 
Part 2 
Page o237  
February 2013  

Received 7 December 2012
Accepted 9 January 2013
Online 16 January 2013

Key indicators
Single-crystal X-ray study
T = 100 K
Mean [sigma](C-C) = 0.003 Å
Disorder in main residue
R = 0.029
wR = 0.066
Data-to-parameter ratio = 17.4
Details
Open access

1-tert-Butyl 2-ethyl 5-bromo-3-(thiophen-2-ylcarbonyl)-1H-indole-1,2-dicarboxylate

aDepartment of Chemistry and Polymer Science, University of Stellenbosch, Private Bag X1, Matieland 7602, South Africa
Correspondence e-mail: hassam@sun.ac.za

In the title compound, C21H20BrNO5S, the thiophene group is located above the mean plane of the indole ring and displays rotational disorder (i.e. rotation through 180°). The site occupancy of the major component is 0.902 (2), while that of the minor component is 0.098 (2). In the crystal, pairs of weak C-H...O interactions link the molecules into centrosymmetric dimers.

Related literature

For background to the use of indoles as scaffolds in the synthesis of HIV-agents, see: Hassam et al. (2012[Hassam, M., Basson, A. E., Liotta, D. C., Morris, L., van Otterlo, W. A. L. & Pelly, S. C. (2012). ACS Med. Chem. Lett. 3, 470-475.]) and for a recent review on stages of non-nucleoside reverse transcriptase inhibitors, see: Reynolds et al. (2012[Reynolds, C., Koning, C. B., Pelly, S. C., van Otterlo, W. A. L. & Bode, M. L. (2012). Chem. Soc. Rev. 41, 4657-4670.]). For the crystal structures of closely related compounds, see: Beddoes et al. (1986[Beddoes, R. L., Dalton, L., Joule, J. A., Mills, O. S., Street, J. D. & Watt, C. I. F. (1986). J. Chem. Soc. Perkin Trans. 2, pp. 787-797.]), Hassam & Smith (2012[Hassam, M. & Smith, V. J. (2012). Acta Cryst. E68, o3357.]).

[Scheme 1]

Experimental

Crystal data
  • C21H20BrNO5S

  • Mr = 478.35

  • Monoclinic, C 2/c

  • a = 16.220 (3) Å

  • b = 15.361 (3) Å

  • c = 18.224 (4) Å

  • [beta] = 113.792 (2)°

  • V = 4154.7 (15) Å3

  • Z = 8

  • Mo K[alpha] radiation

  • [mu] = 2.11 mm-1

  • T = 100 K

  • 0.34 × 0.21 × 0.17 mm

Data collection
  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan [symmetry-related measurements (SADABS; Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.])] Tmin = 0.537, Tmax = 0.721

  • 23562 measured reflections

  • 4855 independent reflections

  • 4101 reflections with I > 2[sigma](I)

  • Rint = 0.039

Refinement
  • R[F2 > 2[sigma](F2)] = 0.029

  • wR(F2) = 0.066

  • S = 1.05

  • 4855 reflections

  • 279 parameters

  • 13 restraints

  • H-atom parameters constrained

  • [Delta][rho]max = 0.38 e Å-3

  • [Delta][rho]min = -0.38 e Å-3

Table 1
Hydrogen-bond geometry (Å, °)

D-H...A D-H H...A D...A D-H...A
C12A-H12A...O3i 0.95 2.48 3.418 (5) 169
Symmetry code: (i) [-x, y, -z+{\script{1\over 2}}].

Data collection: APEX2 (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); cell refinement: SAINT (Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]); data reduction: SAINT; 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: X-SEED (Barbour, 2001[Barbour, L. J. (2001). J. Supramol. Chem. 1, 189-191.]; Atwood & Barbour, 2003[Atwood, J. L. & Barbour, L. J. (2003). Cryst. Growth Des. 3, 3-8.]); software used to prepare material for publication: X-SEED.


Supplementary data and figures for this paper are available from the IUCr electronic archives (Reference: JJ2160 ).


Acknowledgements

MH thanks Professor Willem A. L. van Otterlo and Dr S. C. Pelly for their valuable input and research oversight. Stellenbosch University's Science Faculty is also acknowledged for providing laboratory space and financial research support (Subcommittee B). The South African National Research Foundation (NRF), Pretoria, is also acknowledged for providing research funds.

References

Atwood, J. L. & Barbour, L. J. (2003). Cryst. Growth Des. 3, 3-8.  [CrossRef] [ChemPort]
Barbour, L. J. (2001). J. Supramol. Chem. 1, 189-191.  [CrossRef] [ChemPort]
Beddoes, R. L., Dalton, L., Joule, J. A., Mills, O. S., Street, J. D. & Watt, C. I. F. (1986). J. Chem. Soc. Perkin Trans. 2, pp. 787-797.
Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.
Hassam, M., Basson, A. E., Liotta, D. C., Morris, L., van Otterlo, W. A. L. & Pelly, S. C. (2012). ACS Med. Chem. Lett. 3, 470-475.  [CrossRef] [ChemPort]
Hassam, M. & Smith, V. J. (2012). Acta Cryst. E68, o3357.  [CSD] [CrossRef] [details]
Reynolds, C., Koning, C. B., Pelly, S. C., van Otterlo, W. A. L. & Bode, M. L. (2012). Chem. Soc. Rev. 41, 4657-4670.  [ISI] [CrossRef] [ChemPort] [PubMed]
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]


Acta Cryst (2013). E69, o237  [ doi:10.1107/S1600536813000809 ]

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