To a stirring solution of 5-(4-ethoxy-2-hydroxy-3-methoxyphenyl)isobenzofuran-1(3H)-one (80 mg, 0.266 mmol) in acetonitrile was added potassium carbonate (110 mg, 0.798 mmol) and propyl bromide (130 mg, 1.066 mmol) and the resultant reaction mixture was heated to 70° C. for 2 h. The reaction mixture was cooled to RT, filtered through celite and the filtrate was concentrated under reduced pressure. Purification of the residue by flash column chromatography (silica gel, 0-25% ethyl acetate in pet ether) afforded the title compound as a solid (20 mg, 22%).
