Tin tetrachloride → 1-[2-(6-Methoxy-2-naphthyl)-1-benzofuran-3-yl]-1-pentanone

Participants

Reaction Conditions

Reaction Steps

To a stirring mixture of 2-(6-methoxy-2-naphthyl)-1-benzofuran (4.02 g, 14.7 mmol) in chloroform (70 mL) chilled in an ice bath was added valeryl chloride (2.6 mL, 22 mmol). The reaction mixture was chilled to −20° C. and tin (IV) chloride (2.2 mL, 19 mmol) was added, dropwise. The mixture was then stirred at room temperature for one hour and then refluxed for 3 hours, 20 minutes. It was allowed to cool to room temperature and poured into ice. The organic phase was diluted with excess ethyl acetate and washed with water and brine. The organic phase was dried over anhydrous magnesium sulfate, filtered and solvent evaporated. The residue was purified twice by flash chromatography (Biotage apparatus) using 2% ethyl acetate in hexane and 10-50% chloroform in hexane to afford 1-[2-(6-methoxy-2-naphthyl)-1-benzofuran-3-yl]-1-pentanone as a yellow gum (3.17 g). Mass spectrum (+EI, M+) m/z358. 1HNMR (400 MHz, DMSO-d6): δ8.35 (s, 1H), 8.0-8.05 (m, 3H), 7.8 (dd, 1H, J=8.5 Hz and 1.7 Hz), 7.7-7.75 (m, 1H), 7.4-7.45 (m, 3H), 7.25-7.3 (m, 1H), 3.9 (s, 3H), 2.7 (t, 2H, J=7.3 Hz), 1.5-1.6 (m, 2H), 1.1-1.2 (m, 2H), and 0.7 ppm (t, 3H, J=7.4 Hz).

Provenance & Evidence