addenda and errata\(\def\hfill{\hskip 5em}\def\hfil{\hskip 3em}\def\eqno#1{\hfil {#1}}\)

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ISSN: 2056-9890

Capecitabine from X-ray powder synchrotron data. Corrigendum

aDepartment of Solid State Chemistry, ICT Prague, Technicka 5, Prague, Czech Republic, bIVAX Pharmaceuticals s.r.o., R&D, Opava, Czech Republic, cPharmaceuticals Research and Development, Branisovska 31, Ceske Budejovice, Czech Republic, and dID31 Beamline, ESRF, 6 rue Jules Horowitz, BP 220, F-38043 Grenoble Cedex, France
*Correspondence e-mail: rohlicej@vscht.cz

Edited by W. T. A. Harrison, University of Aberdeen, Scotland (Received 20 May 2016; accepted 20 May 2016; online 27 May 2016)

In the paper by Rohlicek et al. [Acta Cryst. (2009), E65, o1325–o1326], one H atom was placed incorrectly.

Following our powder-diffraction study of capecitabine (Rohlicek et al., 2009[Rohlicek, J., Husak, M., Gavenda, A., Jegorov, A., Kratochvil, B. & Fitch, A. (2009). Acta Cryst. E65, o1325-o1326.]), Malińska et al. (2014[Malińska, M., Krzecyński, P., Czerniec-Michalik, E., Trzcińska, K., Cmoch, P., Kutner, A. & Woźniak, K. (2014). J. Pharm. Sci. 103, 587-593.]) published the crystal structure of the same mol­ecule based on single-crystal data. Although they modelled the wrong enanti­omer [as was pointed out by Kratochvil et al. (2016[Kratochvil, B., Husak, M., Korotkova, E. I. & Jegorov, A. (2016). Chem. Listy, 110, 40-47.])], the structures are very similar after inverting the single-crystal structure, including the disordered part of the mol­ecule (Fig. 1[link]). Since single-crystal diffraction is more sensitive to H atoms than powder diffraction, Malinska et al. (2014[Malińska, M., Krzecyński, P., Czerniec-Michalik, E., Trzcińska, K., Cmoch, P., Kutner, A. & Woźniak, K. (2014). J. Pharm. Sci. 103, 587-593.]) were able to locate the H atoms directly. This indicated a different tautomeric form of capecitabine to that assumed in our study, and as they pointed out, we had therefore placed one H atom wrongly.

In our defence, in the powder study, we placed the H atoms geometrically according to a reasonable chemical structure for capecitabine, which shows the tautomeric H atom attached to the N atom of the carbamate group and the plausible formation of an inter­molecular N—H⋯O hydrogen bond. As shown by Malińska et al. (2014[Malińska, M., Krzecyński, P., Czerniec-Michalik, E., Trzcińska, K., Cmoch, P., Kutner, A. & Woźniak, K. (2014). J. Pharm. Sci. 103, 587-593.]), the H atom is actually located on the N atom of the pyrimidine ring (Fig. 2[link]), thereby forming an intra­molecular N—H⋯O link.

With respect to the fact that structure solution from powder diffraction data is based on the proposed molecular structure, readers should beware of the incorrectly placed H atom in Rohlicek et al. (2009[Rohlicek, J., Husak, M., Gavenda, A., Jegorov, A., Kratochvil, B. & Fitch, A. (2009). Acta Cryst. E65, o1325-o1326.]) and they should be also beware of the wrong enantiomer in a single-crystal study of Malińska et al. (2014[Malińska, M., Krzecyński, P., Czerniec-Michalik, E., Trzcińska, K., Cmoch, P., Kutner, A. & Woźniak, K. (2014). J. Pharm. Sci. 103, 587-593.]).

References

First citationKratochvil, B., Husak, M., Korotkova, E. I. & Jegorov, A. (2016). Chem. Listy, 110, 40–47.  Google Scholar
First citationMalińska, M., Krzecyński, P., Czerniec-Michalik, E., Trzcińska, K., Cmoch, P., Kutner, A. & Woźniak, K. (2014). J. Pharm. Sci. 103, 587–593.  PubMed Google Scholar
First citationRohlicek, J., Husak, M., Gavenda, A., Jegorov, A., Kratochvil, B. & Fitch, A. (2009). Acta Cryst. E65, o1325–o1326.  Web of Science CSD CrossRef CAS IUCr Journals Google Scholar

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

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ISSN: 2056-9890
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