A simple synthesis of functionalized 3-bromocoumarins by a one-pot three-component reaction

Functionalized 3-bromocoumarins 2 have been, prepared, by a simple one-pot bromination/Wittig/cyclization tandem process from methyl (triphenylphosphoranylidene)acetate, Nbromosuccinimide and a series of 2-hydroxybenzaldehydes. Owing to the commercial availability of salicylaldehyde derivatives, this approach offers such a diverse range of compounds that it fulfills the recent demand for the generation of large combinatorial chemical libraries based on the coumarin scaffold