Synthesis and Radical Scavenging Activity of Substituted Benzo[h]chromanols

Benzo[h]chromanols, which possess a tocopherol moiety, have been reported to exhibit potent antioxidant activity.Several benzo[h]chromanols with various substituents (nitro, chloro, bromo, methyl, or amino groups at the position ortho to the phenolic OH group) were synthesized, and the second-order rate constants (k) of their reaction with the galvinoxyl radical were determined.The introduction of electron-withdrawing bromo, chloro and nitro groups decreased the activity, and the activity correlated well with the substituent effect.ortho-Aminobenzo[h]chromanol showed the highest radical scavenging activity among the compounds synthesized.