A novel method for the synthesis of oxazolocoumarin derivatives

Anodic oxidation of 7-hydroxycoumarin derivatives 1a-f in anhyd acetonitrile-lithium perchlorate at constant potential between 1.70-1.80 V (vs. Ag/10(-2) M Ag+) using an undivided cell and platinium gauze electrodes leads to the formation of the corresponding oxazolocoumarin derivatives 2 and/or 3 according to the position of the second OH group in the benzene ring of the coumarin derivatives 1e.f. The formation of these oxidation products is discussed.