Novel 2-heteryl substituted 5-fluoro-1,3-benzothiazin-4-ones and 6,7,8-trifluoro-1,3-benzothiazin-4-ones have been prepared in good to excellent yields by reacting o-fluorobenzoyl isothiocyanates with C-nucleophiles, followed by cyclization of the intermediates in the presence of a base. Fluorinated benzothiazinones have been characterized by 1H, 13C, and 19F NMR, mass-spectrometry and X-ray crystallography data.