反应详情

581 mg (1.56 mmol) of the compound from example 47A were introduced in portions at 0° C. into conc. sulfuric acid (2.0 ml) and the mixture was stirred for a further 30 min. Subsequently, the solution was added to ice and extracted twice with ethyl acetate. The combined organic phases were dried over sodium sulfate, filtered and concentrated. The residue was stirred with ethyl acetate, and the solids were filtered off and dried under high vacuum. This gave 246 mg (40% of theory) of the title compound in solid form.

1. additionSubsequently, the solution was added to ice
2. extractionextracted twice with ethyl acetate
3. dry with materialThe combined organic phases were dried over sodium sulfate
4. filtrationfiltered
5. concentrationconcentrated
6. stirringThe residue was stirred with ethyl acetate
7. filtrationthe solids were filtered off
8. customdried under high vacuum