反应详情

A stirred solution of compound A3 (30.0 g, 93.75 mmol) in TFA (54.5 mL) was heated to 80° C. and stirred for 12 h under inert atmosphere. The reaction was monitored by TLC; after completion of the reaction, the volatiles were removed under reduced pressure. The residue was dissolved in ice-cold water (100 mL), basified with solid sodium bicarbonate and extracted with EtOAc (2×200 mL). The combined organic extracts were dried over Na2SO4, filtered and concentrated under reduced pressure to obtain the crude. The crude was purified through silica gel column chromatography using 3% EtOAc/Hexanes to afford compound 6 (11.7 g, 62%) as a pale brown syrup. 1H NMR (500 MHz, CDCl3): δ 7.70-7.66 (m, 1H), 7.48-7.44 (m, 1H), 7.08-7.04 (m, 1H), 4.20 (q, J=7.5 Hz, 2H), 3.67 (s, 1H), 1.40 (t, J=7.5 Hz, 3H); LC-MS (ESI): 91.8%; m/z 199.0 (M−H+); (column: X Select CSH C-18, 50×3.0 mm, 3.5 μm); RT 2.60 min; 5 mM NH4OAc: ACN; 0.8 mL/min).

1. customafter completion of the reaction
2. customthe volatiles were removed under reduced pressure
3. dissolutionThe residue was dissolved in ice-cold water (100 mL)
4. extractionextracted with EtOAc (2×200 mL)
5. dry with materialThe combined organic extracts were dried over Na2SO4
6. filtrationfiltered
7. concentrationconcentrated under reduced pressure
8. customto obtain the crude
9. customThe crude was purified through silica gel column chromatography