Synthesis of dihydrocoumarin carbamate derivatives

The condensation at room temperature in the trifluoroacetic acid of para - and meta -hydroxy-substituted methylphenylcarbamate with cinnamic acids or their esters containing electron-donor substituents in the benzene ring yielded dihydrocoumarins with a carbamate function attached to C 6 or C 7 . Under similar conditions the methyl(2-hydroxyphenyl)carbamate, cinnamic acids or their esters containing electron-acceptor substituents or electron-donor substituents in the ortho -position of the benzene ring are not involved into the condensation.