反应详情

温度

0 °C

295.5 g (0.25 mol) of (2R-cis)-1-[[[4-chloro-5-[[(chloromethyl)sulfonyl]amino]-2-fluorophenyl]amino]carbonyl]-4-hydroxy-2-pyrrolidinecarboxylic acid was suspended in 150 g of methyl isobutyl ketone at room temperature. 12.75 g (0.125 mol) of concentrated sulfuric acid was added and the clear solution was heated to reflux. At 90° C. a precipitate appeared. After an additional 20 minutes of stirring at reflux the suspension was cooled to 0° C. and allowed to stir for 1 hour at this temperature. After filtration and drying at 60° C., 91.65 g (86.6%) of the title compound was obtained as beige crystals melting at 198-200° C. (purity: 97%).

1. temperaturethe clear solution was heated to reflux
2. customAt 90° C.
3. temperatureat reflux the suspension
4. stirringto stir for 1 hour at this temperature
5. filtrationAfter filtration
6. customdrying at 60° C.