To a mixture of 2-(2-ethyl-5-hydroxyphenyl)hexahydro-4,7-ethanoindene-1,3-dione (83 mg, 0.28 mmol) and anhydrous potassium carbonate (90 mg, 0.56 mmol) is added a solution of 2,6-dichloroquinoxaline (67 mg, 0.34 mmol) in anhydrous dimethylformamide (2.0 ml), and the mixture is heated at 140° C. for 40 minutes under microwave irradiation. The mixture is acidified with 2M aqueous hydrochloric acid and diluted with dichloromethane then filtered. The organic phase is concentrated under reduced pressure and the residue is purified by preparative reverse phase HPLC to afford 2-[5-(6-chloroquinoxalin-2-yloxy)-2-ethylphenyl]hexahydro-4,7-ethanoindene-1,3-dione.
