反应详情

To a solution of tert-butyl (2-(5-(((tert-butyldiphenylsilyl)oxy)methyl)-2-isobutyryl-6-(methylsulfonyl)-1H-indol-1-yl)ethyl)carbamate (250 mg, 0.37 mmol) in CH2Cl2(5.0 mL) was added trifluoroacetic acid (1.0 mL) and the mixture was allowed to stir at rt for 1 h. The excess amount of TFA was removed by azeotropic evaporation with toluene under reduced pressure. The residue was redissolved in CH2Cl2 (5 mL) and Et3N (0.5 mL) was added. The reaction mixture was stirred at rt for 45 min and concentrated in vacuo. The residue was purified by flash chromatography over silica gel eluting with CH2Cl2/methanol (98/2) to provide 8-(((tert-butyldiphenylsilyl)oxy)methyl)-1-isopropyl-7-(methylsulfonyl)-3,4-dihydropyrazino[1,2-a]indole (135 mg, 65% yield). LC-MS m/z 559 [M+H]+.

1. customThe excess amount of TFA was removed by azeotropic evaporation with toluene under reduced pressure
2. dissolutionThe residue was redissolved in CH2Cl2 (5 mL)
3. additionEt3N (0.5 mL) was added
4. stirringThe reaction mixture was stirred at rt for 45 min
5. concentrationconcentrated in vacuo
6. customThe residue was purified by flash chromatography over silica gel eluting with CH2Cl2/methanol (98/2)