PROCESS FOR PREPARING 2-ETHYL-5,6,7,8-TETRAHYDROANTHRAQUINONE

摘要

PURPOSE: Title compound is prepared by selectively hydrogenating unsubstituted aromatic ring to high yield. CONSTITUTION: 2-Ethyl anthraquinone(formula 2) is hydrogenated at 40- 80°C, 1- 5atm of hydrogen pressure in organic solvent having 70- 102°C of boiling point in the presence of 0.5- 5 weight % of palladium catalyst supported on active carbon, alumina or silica, followed by oxidation with oxygen or air to give 2-ethyl-5,6,7,8-tetrahydroanthraquinone(formula 1). Thus, 250 g of 2-ethyl anthraquinone is reduced at 40°C for 10 hours in 1 l of dioxin in the presence of 25 g of 5 weight % of Pd/Al catalyst. Obtained solution is filtrated and oxidated for 60 minutes in 300 ml flow of oxygen to give the title compound.