1-(3,4-dimethoxyphenyl)-2,3-bis(ethoxycarbonyl)-4-hydroxy-6,7,8-trimethoxynaphthalene 、
sodium methylate 以whereby 1-(3,4-dimethoxyphenyl)-2-ethoxycarbonyl-3-methoxycarbonyl-4-hydroxy-6,7,8-trimethoxynaphthalene is obtained as colorless prisms的产率得到1-(3,4-dimethoxyphenyl)-2-ethoxycarbonyl-3-methoxycarbonyl-4-hydroxy-6,7,8-trimethoxynaphthalene