Ethyl Acetate → 5-Bromo-4-fluoro-2-(2-fluoro-4-methoxyphenoxy)benzoic acid

関与物質

反応手順

A 2 L RB flask was charged with 2-fluoro-4-methoxyphenol (49.6 g, 349 mmol), 2,5-dibromo-4-fluorobenzoic acid (80 g, 269 mmol), ethyl acetate (1.316 mL, 13.43 mmol), cesium carbonate (192 g, 591 mmol) and toluene (1200 mL). To the mixture at was added copper(I) triflate toluene complex (2:1) (1.713 g, 8.06 mmol) and it was stirred at room temperature for 20 minutes. The solution was then heated to 75° C. for 16 hours at which point the toluene was removed under reduced pressure. The solution was dissolved in 1.5 liters of water and washed with 250 ml of EtOAc. The aqeuous layer was acidified to pH 1 with concentrated HCl and the resulting precipitant was collected by filtration and washed with water. The derived solid was washed with a 1:1 solution of ethyl acetate and hexane, then dried under vacuum to afford 5-bromo-4-fluoro-2-(2-fluoro-4-methoxyphenoxy)benzoic acid as a light brown solid. MS m/z=358.8 [M+H].

情報源と証拠