Cesium carbonate → 4-Bromo-1-chloro-2-[[4-(2,2,2-trifluoroethoxy)phenyl]methyl]benzene

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Reaction Steps

4-[(5-bromo-2-chloro-phenyl)methyl]phenol 7c (14.5 g, 48.7 mmol, prepared according to the method in WO2009026537) was dissolved in 300 mL DMF, followed by addition of cesium carbonate (31.7 g, 97.5 mmol). The reaction mixture was stirred for 10 minutes. The reaction mixture was stirred for 8 hours at 80° C. after 2,2,2-trifluoroethyl-4-methylbenzenesulfonate 7b (12.4 g, 48.7 mmol) was added. Thereafter, the reaction mixture was filtered and washed with a small amount of ethyl acetate before the filtrate was concentrated under reduced pressure. The resulting residue was partitioned after 100 mL water and 50 mL saturated sodium chloride solution were added. The aqueous phase was extracted with ethyl acetate (100 mL×3) and the organic extract was washed with saturated sodium chloride solution (100 mL), combined and concentrated. The resulting residue was purified by silica gel chromatography with elution system B to obtain the title compound 4-bromo-1-chloro-2-[[4-(2,2,2-trifluoroethoxy)phenyl]methyl]benzene 7d (7.26 g, white solid), yield: 39.2%. 1H NMR (400 MHz, CDCl3): δ 7.32 (s, 1H), 7.30-7.24 (m, 2H), 7.21-7.14 (m, 2H), 6.98-6.87 (m, 2H), 4.38 (d, 2H), 4.06 (s, 2H).

Provenance & Evidence