反应详情

温度

0 °C

Using an ice-acetone bath, 48.6 ml of trifluoroacetic acid (TFA and 12.1 ml of 70% strength nitric acid are cooled to −10° C., 3.0 g (8.86 mmol) of the compound from example 25A, dissolved in 7 ml of TFA are added dropwise, and the mixture is stirred at 0° C. for 20 hours. The reaction solution is stirred into 400 ml of ice-water and 200 ml of dichloromethane and neutralized using about 200 ml of saturated sodium bicarbonate solution. The aqueous phase is separated off and extracted 3 times with dichloromethane, and the combined organic phases are dried and concentrated. The residue is chromatographed on silica gel using toluene with added ethyl acetate in a gradient from 11 to 60%.

1. additionare added dropwise
2. customThe aqueous phase is separated off
3. extractionextracted 3 times with dichloromethane
4. customthe combined organic phases are dried
5. concentrationconcentrated
6. customThe residue is chromatographed on silica gel