Following the procedure described in Step 2 of Example 1, 2-(6-methoxy-2-naphthyl)-1-benzofuran (6.00 g, 21.9 mmol) was acylated with 2-cyclopentylacetyl chloride (3.51 g, 23.9 mmol) using tin (IV) chloride (2.8 mL, 24 mmol) in carbon disulfide (120 mL). Purification by flash chromatography (Biotage apparatus) using 10-25% chloroform in hexane and 0.5-1% ethyl acetate in hexane as eluants furnished the title compound as a yellow gum (4.98 g); 1HNMR (200 MHz, DMSO-d6): δ8.35 (s, 1H), 8.0 (d, 3H, J=8.7 Hz), 7.8 (d, 1H, J=8.7 Hz), 7.7-7.8 (m, 1H), 7.35-7.5 (m, 3H), 7.2-7.35 (m, 1H), 3.95 (s, 3H), 2.75 (d, 2H, J=7.7 Hz), 2.1-2.3 (m, 1H), 1.5-1.75 (m, 2H), 1.3-1.5 (m, 4H), and 0.8-1.1 ppm (m, 2H).
