反应详情

X-Phos (1.1 g, 2.2 mmol.), Pd2(dba)3 (1.0 g, 1.1 mmol) and cesium carbonate (14.5 g, 44 mmol) were added to a degassed solution of ethyl 4-chlorobenzofuran-2-carboxylate (Example 1b), 5.0 g, 22 mmol) and benzylpiperazine (5.8 ml, 33 mmol) in dioxane (100 mL). The reaction mixture was heated to +110° C. for 3 h, cooled to room temperature, filtered through a short pad of Celite and the filtrate was concentrated under reduced pressure. The crude residue was purified by silica gel column chromatography by using hexane/ethyl acetate (3/1) as eluant to give the title compound. Yield: 7.0 g (86%). 1H NMR (400 MHz, CDCl3) δ ppm 1.43 (t, 3H) 2.69 (m, 4H) 3.28 (m, 4H) 4.46 (q, 2H) 6.68 (d, 1H) 7.20-7.43 (m, 7H) 7.59 (s, 1H).

1. temperatureThe reaction mixture was heated to +110° C. for 3 h
2. filtrationfiltered through a short pad of Celite
3. concentrationthe filtrate was concentrated under reduced pressure
4. customThe crude residue was purified by silica gel column chromatography