反应详情

To a solution of methyl 2-t-butoxycarbonylamino-5-trifluoromethyl-benzoate (3.80 g; prepared in Reference Example 27.) in methylene chloride (30 ml), trifluoroacetic acid (6 ml) was added. The mixture was stirred for 8 hours at room temperature. The solvent was distilled off azeotropically with toluene three times. To the reaction mixture, an aqueous sodium hydrogencarbonate solution was added to neutralize. The mixture was extracted with ethyl acetate, washed, dried, filtered and concentrated under the reduced pressure. The residue was purified on silica gel column chromatography (hexane:AcOEt=5:1) to give the title compound (2.35 g) having the following physical data.

1. distillationThe solvent was distilled off azeotropically with toluene three times
2. additionTo the reaction mixture, an aqueous sodium hydrogencarbonate solution was added
3. extractionThe mixture was extracted with ethyl acetate
4. washwashed
5. customdried
6. filtrationfiltered
7. concentrationconcentrated under the reduced pressure
8. customThe residue was purified on silica gel column chromatography (hexane:AcOEt=5:1)