Abstract
Different substituted 3,3′-arylidenebis-4-hydroxycoumarins (
1–
7) and tetrakis-4-hydroxycoumarin derivative
8 are the final products when 4-hydroxycoumarin and aromatic aldehydes containing different groups in
ortho,
meta or
para positions condense in boiling ethanol or acetic acid. Upon heating 3,3′-arylidenebis-4-hydroxycoumarins, and tetrakis-4-hydroxycoumarin derivative in anhydride acetic acid, the epoxydicoumarins (
9–
16) were formed. From a study of nuclear magnetic resonance and infrared spectra, intramolecularly hydrogen-bonded structures are proposed for the dicoumarols (
1–
8). A possible relationship between such hydrogen-bonded structures and the antimicrobial and the antioxidant activities of compounds
1–
8 is suggested.
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