Modified coumarins. 27. Ssynthesis and antioxidant activity of 3-substituted 5,7-dihydroxy-4-methylcoumarins

Amides of 5,7-dihydroxy-4-methylcoumaryl-3-ylacetic acid were synthesized by the activated ester method using N-hydroxysuccinimide and diisopropylcarbodiimide or by reaction with N,N-carbonylimidazole. The reactivity of 3- substituted 5,7-dihydroxy-4-methylcoumarins toward 2,2-diphenyl-1-picrylhydrazyl and superoxide radical was analyzed. The effect of the synthesized compounds on xanthineoxidase activity was studied.