4-Toluenesulfonyl chloride → 2-(5-Bromo-1-benzofuran-2-yl)ethyl 4-methylbenzenesulfonate

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Reaction Conditions

Reaction Steps

The product from Example 4A (1.21 g, 5.0 mmol), 4-dimethylaminopyridine (0.06 g, 0.5 mmol), and triethylamine (1.5 mL, 10.5 mmol) were combined in dichloromethane (20 mL) stirred briefly and treated with para-toluenesulfonyl chloride (1.91 g, 10.0 mmol) in dichloromethane (2 mL) over about 5 minutes. After stirring at about 22° C. for 3 hours, the mixture was then washed with saturated NaHCO3 solution (20 mL, 2×), brine (20 mL), dried over Na2SO4, and distilled to dryness. The residue in acetonitrile (˜5 mL) was heated at 50° C. to effect dissolution, allowed to cool to room temperature slowly, and then cooled to about 0° C. The slurry was filtered and the obtained solid dried under reduced pressure at 40° C. to provide the title compound (0.95 g, 48% yield). MS-DCI (M+NH4)+ observed m/z at 412, 414; 1H NMR (CDCl3 at 400 MHz) δ 2.38 (s, 3H), 3.11 (m, 2H), 4.35 (m, 2H), 6.35 (m, 1H), 7.1-7.18 (m, 3H), 7.27 (dd, 1H), 7.56 (d, 1H), 7.64-7.67 (m, 2H); 13C NMR (CDCl3 at 100 MHz) δ 21.9, 28.8, 67.1, 103.7, 112.0, 115.5, 122.9, 126.3, 127.4, 129.4, 130.1, 132.3, 144.4, 153.0, 154.2 with 2 peaks overlapping.

Provenance & Evidence