High-intensity ultrasounds have been employed in the synthesis
of 4-hydroxycoumarin derivatives, using mainly water as reaction
medium. Marked improvements of reaction rates, chemoselectivity
and product yields have been observed on comparing sonochemical
with ordinary conditions. In the alkylation of a series of allyl
and benzyl bromides a pathway switch occured to yield 3-alkyl-4-hydroxycoumarin
derivatives.
sonochemistry - ultrasounds - 4-hydroxycoumarin - coumarin derivatives - chemoselectivity
