反应详情

A solution of Example 354 (0.036 g, 0.081 mmol) in dimethylformamide (2 mL) was treated with trimethyl orthoformate (1 mL) and a catalytic amount of para-toluenesulfonic acid at room temperature for 20 hours. The solvent was removed under a stream of warm nitrogen and the residue was triturated with 1:1 ethyl acetate: tetrahydrofuran, filtered, and dried to yield the title compound (8 mg, 22%). MS (ESI−) m/z 452 (M−H)−. 1H NMR (300 MHz, DMSO-d6) δ 1.05 (d, J=6.62 Hz, 6 H) 1.93 (m, 1 H) 2.78 (m, 2 H) 6.33 (m, 1 H) 7.45 (t, J=7.54 Hz, 1 H) 7.73 (d, J=8.82 Hz, 1 H) 7.92 (t, J=7.72 Hz, 1 H) 8.00 (m, 1 H) 8.21 (m, 2 H) 9.04 (s, 1 H) 14.28 (s, 1 H).

1. customThe solvent was removed under a stream of warm nitrogen
2. customthe residue was triturated with 1:1 ethyl acetate
3. filtrationtetrahydrofuran, filtered
4. customdried