Experimental Melting points were measured by using capillary tube method with electro thermal 9100 apparatus. 1H NMR and 13C NMR were recorded on Bruker 500. IR spectra were recorded as KBr discs on a FT-IR Bruker Tensor 27. Mass spectra were measured on Varian CH 7. Difluoro[7-chloro-1-cyclopropyl-6-fluoro-4-oxo-1,4-dihydroquin- oline-3-carboxylato-O3,O4]boron . 4a: In a round bottomed flask (100 cm3) equipped with stirrer and condenser, compound ...
