反应详情

温度

180 °C

A mixture of the monomethyl ether 79 (0.27 g, 1.1 mmol) and Pyr-HCl was heated at 180° C. for 30–45 minutes. The reaction mixture was allowed to cool and partitioned between EtOAc and 2 N HCl aq and the EtOAc was washed with brine and dried over MgSO4. The solution was filtered, concentrated and chromatographed on silica gel (EtOAc/hexanes 1:3): Mp=167–169° C.; 1H NMR (DMSO-d6) δ 8.61 (s, 1 H), 8.11 (s, 1 H), 7.67 (d, 1 H, J=8.9 Hz), 7.33 (d, 1 H, J=8.7 Hz), 7.02 (d, 1 H, J=2.4 Hz), 6.82–6.78 (m, 4H (overlapping protons)), 2.50 (s, 3 H); MS 239 (M−H)−.

1. temperatureto cool
2. custompartitioned between EtOAc and 2 N HCl aq
3. washthe EtOAc was washed with brine
4. dry with materialdried over MgSO4
5. filtrationThe solution was filtered
6. concentrationconcentrated
7. customchromatographed on silica gel (EtOAc/hexanes 1:3)