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Eight salt forms of sulfadiazine
Author(s) -
Buist Amanda R.,
Dennany Lynn,
Kennedy Alan R.,
Manzie Craig,
McPhie Katherine,
Walker Brandon
Publication year - 2014
Publication title -
acta crystallographica section c
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.304
H-Index - 17
ISSN - 2053-2296
DOI - 10.1107/s2053229614018725
Subject(s) - sulfonyl , chemistry , bromide , medicinal chemistry , tetrafluoroborate , crystal structure , methanol , hydrate , chloride , inorganic chemistry , crystallography , organic chemistry , catalysis , alkyl , ionic liquid
Proton transfer to the sulfa drug sulfadiazine [systematic name: 4‐amino‐ N ‐(pyrimidin‐2‐yl)benzenesulfonamide] gave eight salt forms. These are the monohydrate and methanol hemisolvate forms of the chloride (2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium chloride monohydrate, C 10 H 11 N 4 O 2 S + ·Cl − ·H 2 O, (I), and 2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium chloride methanol hemisolvate, C 10 H 11 N 4 O 2 S + ·Cl − ·0.5CH 3 OH, (II)); a bromide monohydrate (2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium bromide monohydrate, C 10 H 11 N 4 O 2 S + ·Br − ·H 2 O, (III)), which has a disordered water channel; a species containing the unusual tetraiodide dianion [bis(2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium) tetraiodide, 2C 10 H 11 N 4 O 2 S + ·I 4 2− , (IV)], where the [I 4 ] 2− ion is located at a crystallographic inversion centre; a tetrafluoroborate monohydrate (2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium tetrafluoroborate monohydrate, C 10 H 11 N 4 O 2 S + ·BF 4 − ·H 2 O, (V)); a nitrate (2‐{[(4‐azaniumylphenyl)sulfonyl]azanidyl}pyrimidin‐1‐ium nitrate, C 10 H 11 N 4 O 2 S + ·NO 3 − , (VI)); an ethanesulfonate {4‐[(pyrimidin‐2‐yl)sulfamoyl]anilinium ethanesulfonate, C 10 H 11 N 4 O 2 S + ·C 2 H 5 SO 3 − , (VII)}; and a dihydrate of the 4‐hydroxybenzenesulfonate {4‐[(pyrimidin‐2‐yl)sulfamoyl]anilinium 4‐hydroxybenzenesulfonate dihydrate, C 10 H 11 N 4 O 2 S + ·HOC 6 H 4 SO 3 − ·2H 2 O, (VIII)}. All these structures feature alternate layers of cations and of anions where any solvent is associated with the anion layers. The two sulfonate salts are protonated at the aniline N atom and the amide N atom of sulfadiazine, a tautomeric form of the sulfadiazine cation that has not been crystallographically described before. All the other salt forms are instead protonated at the aniline group and on one N atom of the pyrimidine ring. Whilst all eight species are based upon hydrogen‐bonded centrosymetric dimers with graph set R 2 2 (8), the two sulfonate structures also differ in that these dimers do not link into one‐dimensional chains of cations through NH 3 ‐to‐SO 2 hydrogen‐bonding interactions, whilst the other six species do. The chloride methanol hemisolvate and the tetraiodide are isostructural and a packing analysis of the cation positions shows that the chloride monohydrate structure is also closely related to these.