反应详情

To a solution of 141a (0.1 g, 0.68 mmol) in dry CH2Cl2 (8 mL) was slowly added 1M BBr3 (0.82 mL) at −30° C. under inert atmosphere. The reaction mixture was stirred for 48 h at room temperature. The mixture was again cooled to −30° C. & then MeOH (5 mL) was slowly added to the mixture. After evaporation of solvent, the residue was adjusted to pH 7 with 1M NaOH and then extracted with CHCl3 (3×30 mL). The combined organic layer dried over Na2SO4. After evaporation of solvent, the residue was purified by prep-TLC with CH2Cl2:Acetone:MeOH (10:1:0.2) to give 61 mg (72%) of pure off white solid. 1H NMR (400 MHz, CDCl3) δ 7.92 (s, 1H), 6.78 (dd, J=11.1, 7.1 Hz, 2H), 6.10 (t, J=7.0 Hz, 1H), 3.57 (s, 3H). 13C NMR (100 MHz, CDCl3) δ 158.82, 146.67, 127.63, 114.36, 106.68, 37.28. HRMS (EI) calcd for C6H7NO2 [M]+ 125.0477. found 125.0477.

1. customat −30° C.
2. temperatureThe mixture was again cooled to −30° C.
3. customAfter evaporation of solvent
4. extractionextracted with CHCl3 (3×30 mL)
5. dry with materialThe combined organic layer dried over Na2SO4
6. customAfter evaporation of solvent
7. customthe residue was purified by prep-TLC with CH2Cl2:Acetone:MeOH (10:1:0.2)
8. customto give 61 mg (72%) of pure off white solid