To a solution of 1-[6-benzyloxy-2-hydroxy-3-(5-methyl-7-nitroindan-4-yloxy)phenyl]ethanone (10.0 g) in tetrahydrofuran (15 mL) was added cesium carbonate (7.53 g) under ice-cooling, and then was added dropwise methyl iodide (2.88 mL). After stirring at room temperature overnight, the reaction mixture was evaporated under reduced pressure to dryness. Adding ethyl acetate (30 mL), the mixture was stirred for 30 min. The insoluble material was removed by filtration. The filtrate was evaporated under reduced pressure to dryness to give the title compound (10.2 g).
