Intramolecular Wittig reactions. A new synthesis of coumarins and 2-quinolones

Abstract

o-Hydroxybenzaldehydes (1a-d) on reaction with chloroacetyl chloride in presence of pyridine followed by addition of triphenyl phosphine and base gave coumarins (2a-d). A similar sequence of reactions on o-aminoacetophenone/benzophenone (1e-f) and methyl anthranilate (1g) gave the corresponding 2-quinolones (2e-g).