The faster and more efficient new synthetic methodologies of crystalline hydroxyquinoline carboxylic acids and their fluoro-, thio-and dithioanalogues were elaborated. The FTIR, multinuclear NMR, UV–Vis and single crystal X-ray characteristics of the series of quinoline carboxylic acids have been determined experimentally and rationalized on the basis of DFT calculation method with B3LYP functional.
