In the presence of some metal ions and sodium iodate, 1, 2-naphthoquinone (1) readily reacted with methanol to give 4-methoxy-1, 2-naphthoquinone (2a). The activity of the metal ions increased in the following order: Co (II)< Ni (II)<< Cu (II)< La (III)<< Ce (III). The reaction was remarkably affected by the reaction temperature, reaction time, and molar ratio of the chelating agent. By the use of 1 equivalent of cerium salt to 1, the yield of 2a increased to ...