反应详情

A solution of 25.72 mL (336 mmol) of diketene in 100 mL of toluene is added dropwise at 90° C. to a solution of 51.0 g (288 mmol) of 4-bromoaniline in 200 mL of toluene and the reaction mixture is kept for 5 hours at this temperature. The reaction solution is cooled in the ice bath, and the precipitate formed is filtered and then washed with toluene until the product is virtually colorless. Subsequently it is dried at 50° C. in the circulating air dryer until the weight is constant. Yield: 50.0 g (68% of theoretical); C10H10BrNO2 (M=256.096); calc.: molpeak (M+H)+: 256/258 (Br); found: molpeak (M+H)+: 256/258 (Br); HPLC-MS: 4.7 min (method B).

1. customthe precipitate formed
2. filtrationis filtered
3. washwashed with toluene until the product
4. customSubsequently it is dried at 50° C. in the circulating air dryer until the weight
5. custom4.7 min (method B)