反应详情

Compound 278 (58 mg, 106 μmol) was dissolved in THF (2 mL). Tetrabutylammonium fluoride, 1.0M in THF (0.5 mL, 0.500 mmol) was added and the reaction stirred at room temperature for 4 hours. The solvent was removed to give an orange oil. Silica gel chromatography (gradient elution ethyl acetate+2.5% TEA/0-5% methanol) afforded a yellow solid. This residue was taken up in methanol (2 mL) and HCl in ethanol (1.0M, 0.5 mL) was added. Diethyl ether (20 mL) was added to precipitate the product, which was filtered and dried in vacuo to give compound 277 as a yellow solid (23 mg, 50%). 1H NMR (500 MHz, DMSO-d6) δ 9.72 (s, 1 H) 9.25-9.35 (m, 1 H) 7.94-8.11 (m, 4 H) 7.62-7.77 (m, 2 H) 7.05 (dd, J=8.93, 2.81 Hz, 1 H) 5.37-5.54 (m, 1 H) 4.99 (d, J=3.91 Hz, 1 H) 4.44 (br. s., 1 H) 3.46 (dd, J=10.03, 4.89 Hz, 2 H) 3.05-3.16 (m, 1 H) 2.26-2.42 (m, 3 H) 1.96-2.20 (m, 8 H) 1.85-1.96 (m, 2 H) 1.66-1.83 (m, 3 H) ppm.

1. customThe solvent was removed
2. customto give an orange oil
3. washSilica gel chromatography (gradient elution ethyl acetate+2.5% TEA/0-5% methanol)
4. customafforded a yellow solid
5. customto precipitate the product, which
6. filtrationwas filtered
7. customdried in vacuo