To a solution of 7-benzyl-8-(3-(trifluoromethoxy)phenoxy)-1H-purine-2,6(3H,7H)-dione (390 mg, 0.93 mmol) in DMF (3 mL) was added iodoethane (150 mg, 0.962 mmol), followed by potassium carbonate (350 mg, 2.54 mmol). The reaction was stirred at 40° C. for 2 h. The mixture was cooled and partitioned between ethyl acetate and water. The organic phase was washed with brine, dried over sodium sulfate, and concentrated to give 7-benzyl-3-ethyl-8-(3-(trifluoromethoxy)phenoxy)-1H-purine-2,6(3H,7H)-dione (271 mg, 65.2% yield) as yellow solid. LCMS retention time 1.765 min; LCMS MH+ 447.
