2-Chloro-3-nitro-5-(trifluoromethyl)benzoic acid and -benzamide: structural characterization of two precursors for antitubercular benzothiazinones

Autor: Adrian Richter, Richard Goddard, Tom Schlegel, Peter Imming, Rüdiger W. Seidel
Jazyk: angličtina
Rok vydání: 2021
Předmět:
Zdroj: Acta Crystallographica Section E: Crystallographic Communications, Vol 77, Iss 2, Pp 142-147 (2021)
Druh dokumentu: article
ISSN: 2056-9890
20569890
DOI: 10.1107/S2056989021000517
Popis: 8-Nitro-1,3-benzothiazin-4-ones are a promising class of new antitubercular agents, two candidates of which, namely BTZ043 and PBTZ169 (INN: macozinone), have reached clinical trials. The crystal and molecular structures of two synthetic precursors, 2-chloro-3-nitro-5-(trifluoromethyl)benzoic acid, C8H3ClF3NO4 (1), and 2-chloro-3-nitro-5-(trifluoromethyl)benzamide, C8H4ClF3N2O3 (2), are reported. In 1 and 2, the respective carboxy, carboxamide and the nitro groups are significantly twisted out of the plane of the benzene ring. In 1, the nitro group is oriented almost perpendicular to the benzene ring plane. In the crystal, 1 and 2 form O—H...O and N—H...O hydrogen-bonded dimers, respectively, which in 2 extend into primary amide tapes along the [101] direction. The trifluoromethyl group in 2 exhibits rotational disorder with an occupancy ratio of 0.876 (3):0.124 (3).
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