反应详情

7.82 g (25.50 mmol) of 2-(4-bromopyridin-2-yl)-1-(4-fluorophenyl)ethanone oxime are placed in a round-bottomed flask and dissolved in 400 mL of 1,2-dichloroethane. An O-(mesitylenesulfonyl)hydroxylamine solution (0.27 M in 1,2-dichloroethane—compound obtained according to the protocol described in step 1.3) is added dropwise to the medium cooled to about 0° C. After the addition, the medium is stirred at room temperature for 1 hour 30 minutes. The medium is then diluted with 200 mL of water and 200 mL of sodium hydroxide solution (1N). The two-phase medium is stirred and the phases are then separated by settling. The organic phase is separated out and the aqueous phase is then extracted 4 times with 200 mL of dichloromethane. The organic phases are then combined, dried over sodium sulfate and filtered. 15 g of silica are then added to the filtrate, and the resulting mixture is then concentrated under reduced pressure. The powder obtained is used as solid deposit for a chromatography on silica gel, eluting with a mixture of cyclohexane and dichloromethane (1/1). 5.06 g (68%) of compound are obtained in the form of a fleecy white powder.