Pd/C-mediated synthesis of (Z)-3-alkylidenephthalides of potential pharmacological interest

The coupling of o-bromobenzoic acid with terminal alkynes using 10% Pd/C–Et3N–CuI–PPh3 as a catalyst system leads to the synthesis of (Z)-3-alkylidenephthalides as the major product along with the traces of isocoumarin when the reaction was performed in 1,4-dioxane. The methodology afforded a range of compounds including (Z)-3-(4-(methylsulfonyl)benzylidene)isobenzofuran-1(3H)-one of potential pharmacological interest.