反应详情

温度

110 °C

4.5 g (21.12 mmol) of 5-bromo-1,3-dihydrobenzimidazol-2-one is added batchwise at 60° C. to a melt of 30.27 g (105.6 mmol) of phosphorus oxybromide and the reaction mixture is stirred for 5 hours at 110° C. Then the reaction mixture is poured onto water and the precipitate formed is filtered off. The precipitate is stirred with DIPE/acetone (4:1) and the solid is filtered off. The solid is dried in the circulating air dryer at 50° C. Yield: 3.4 g (58% of theoretical); C7H4Br2N2 (M=275.92); calc.: molpeak (M+H)+: 275/277/279; found: molpeak (M+H)+: 275/277/279; Rf value: 0.6 (silica gel, DCM/MeOH 10:1).

1. additionThen the reaction mixture is poured onto water
2. customthe precipitate formed
3. filtrationis filtered off
4. stirringThe precipitate is stirred with DIPE/acetone (4:1)
5. filtrationthe solid is filtered off
6. customThe solid is dried in the circulating air dryer at 50° C