[Journal logo]

Volume 69 
Part 3 
Page o446  
March 2013  

Received 20 February 2013
Accepted 20 February 2013
Online 28 February 2013

Key indicators
Single-crystal X-ray study
T = 100 K
Mean [sigma](C-C) = 0.002 Å
Disorder in main residue
R = 0.034
wR = 0.084
Data-to-parameter ratio = 16.1
Details
Open access

1-tert-Butyl 2-ethyl 5-chloro-3-(2-furoyl)-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, C21H20ClNO6, the furan moiety 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 0.809 (6). In the crystal, C-H...O interactions link the molecules into chains which run parallel to the b axis.

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., 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., 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.], 2013[Hassam, M. & Smith, V. J. (2013). Acta Cryst. E69, o237.]).

[Scheme 1]

Experimental

Crystal data
  • C21H20ClNO6

  • Mr = 417.83

  • Monoclinic, P 21 /c

  • a = 9.8354 (8) Å

  • b = 8.0938 (7) Å

  • c = 25.435 (2) Å

  • [beta] = 99.344 (1)°

  • V = 1997.9 (3) Å3

  • Z = 4

  • Mo K[alpha] radiation

  • [mu] = 0.23 mm-1

  • T = 100 K

  • 0.32 × 0.32 × 0.24 mm

Data collection
  • Bruker APEXII CCD diffractometer

  • Absorption correction: multi-scan (SADABS; Bruker, 2009[Bruker (2009). APEX2, SAINT and SADABS. Bruker AXS Inc., Madison, Wisconsin, USA.]) Tmin = 0.930, Tmax = 0.947

  • 11690 measured reflections

  • 4483 independent reflections

  • 3877 reflections with I > 2[sigma](I)

  • Rint = 0.019

Refinement
  • R[F2 > 2[sigma](F2)] = 0.034

  • wR(F2) = 0.084

  • S = 1.05

  • 4483 reflections

  • 279 parameters

  • 8 restraints

  • H-atom parameters constrained

  • [Delta][rho]max = 0.29 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
C13A-H13A...O5i 0.95 2.37 3.187 (3) 144
Symmetry code: (i) [-x+2, y+{\script{1\over 2}}, -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: ZL2535 ).


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., 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]
Hassam, M. & Smith, V. J. (2013). Acta Cryst. E69, o237.  [CrossRef] [details]
Reynolds, C., Koning, C. B., Pelly, S. C., Otterlo, W. A. L. & Bode, M. L. (2012). Chem. Soc. Rev. 41, 4657-4670.  [CrossRef] [ChemPort] [PubMed]
Sheldrick, G. M. (2008). Acta Cryst. A64, 112-122.  [CrossRef] [details]


Acta Cryst (2013). E69, o446  [ doi:10.1107/S1600536813005059 ]

This is an open-access article distributed under the terms of the Creative Commons Attribution Licence, which permits unrestricted use, distribution, and reproduction in any medium, provided the original authors and source are cited.