Monohydrous dihydrogen phosphate salts of norfloxacin and ciprofloxacin.
Norfloxacin and ciprofloxacin crystallize with phosphoric acid in aqueous solution to give the salts 4-(3-carboxy-1-ethyl-6-fluoro-4-oxo-1,4-dihydro-7-quinolyl)piperazinium dihydrogenphosphate monohydrate, C16H19FN3O3(+) x H2PO4(-) x H2O, and 4-(3-carboxy-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydro-7-quinolyl)piperazinium dihydrogenphosphate monohydrate, C17H19FN3O3(+) x H2PO4(-) x H2O, respectively. In the crystal structures, the phosphate anions and the piperazine rings of norfloxacin or ciprofloxacin form a 12-membered supramolecular synthon, viz. R4(4)(12). The synthons R4(4)(12) and R2(2)(8) formed between adjacent phosphate anions result in the three-dimensional structures.
Lou
Benyong
B
Department of Health Science, Luleå University of Technology, Luleå S-971 87, Sweden.
Boström
Dan
D
Velaga
Sitaram P
SP
D000838:Anions / Q000737:chemistry; D002939:Ciprofloxacin / Q000737:chemistry*; D003460:Crystallization; D018360:Crystallography, X-Ray; D006860:Hydrogen Bonding; D015394:Molecular Structure; D009643:Norfloxacin / Q000737:chemistry*; D010756:Phosphoric Acids / Q000737:chemistry*; D012996:Solutions / Q000737:chemistry; D014867:Water / Q000737:chemistry
D000838:Anions; D010756:Phosphoric Acids; D012996:Solutions; D014867:Water; D002939:Ciprofloxacin; C030242:phosphoric acid; D009643:Norfloxacin