反应详情

To a stirring solution of 271 (0.14 g, 0.31 mmol) in 6 mL CH2Cl2 (6 mL), chilled to −20° C. under N2, was added BBr3 (0.24 g, 0.94 mmol) dropwise, via syringe, over 1 minute. After 90 min at −20° C. the r×n was poured over 50 g ice followed by EtOAc (50 mL). The EtOAC layer was washed with brine (50 mL), dried (Na2SO4) and concentrated to a viscous yellow oil that was purified by column chromatography using a gradient of 100% DCM to 1% MeOH: CH2Cl2 to yield a foam. The foam is crystallized from EtOAc/hexanes to yield the title compound 272, as a light yellow solid (72 mg, 55%). 1H NMR (400 MHz, DMSO-d6): δ 1.13 (t, J=7.3 Hz, 3H), 2.13 (s, 3H), 4.01 (q, J=7.3 Hz, 2H), 6.53 (d, J=8.9 Hz, 2H), 6.94 (d, J=8.9 Hz, 2H), 6.97 (dd, J1=2.3 Hz, J2=9.1 Hz, 1H), 7.11-7.30 (m, 5H), 7.54 (s, 1H), 7.55 (d, J=8.8 Hz, 1H), 9.40 (s, 1H), 9.81 (s, 1H).

1. washThe EtOAC layer was washed with brine (50 mL)
2. dry with materialdried (Na2SO4)
3. concentrationconcentrated to a viscous yellow oil that
4. customwas purified by column chromatography
5. customCH2Cl2 to yield a foam
6. customThe foam is crystallized from EtOAc/hexanes