Synthesis of new 2H-2-iminocoumarins incorporating fluorobenzene moiety

Fluorine plays a crucial role in modern pharmaceutical development owing to its distinct properties, such as high electronegativity and a compact atomic size. These features enable fluorine to improve a drug efficacy, selectivity, metabolic stability, and cell membrane permeability. To leverage these benefits, chromene-3-carboxamide derivatives (15a–e), incorporating a 2-fluorobenzene core, were synthesized by condensing salicylaldehydes (14a-d) or 1-hydroxy-2- naphthaldehyde (14e) with N-(2-fluorophenyl)acetamide (13) in a piperidine/ethanol mixture.