反应详情

A solution of 19 (8.60 g, 16.71 mmol) in dioxane (84 mL) and 2N NaOH (42 mL) was stirred for 24 h at room temperature. The reaction mixture was concentrated in vacuo. The residue was stirred with H2O (100 mL) and then acidified to pH 2 with 1N HCl. The white solid was filtered, washed with hexane, and was recrystallised from EtOAc/hexanes to generate 5.93 g (90%) of 20 as a white crystalline solid, mp 129° C.: 1H NMR δ 3.8 (s, 3H), 3.85 (s, 3H), 5.12 (s, 2H), 5.20 (s, 2H), 6.83 (d, 2H, J=8.8), 6.96 (d, 2H, J=9.2), 7.18 (t, 2H, J=8.0), 7.22-7.27 (m, 2H), 7.41 (d, 2H, J=8.4), 7.73 (dd, 1H, J=1.2, 8.0); 13C NMR δ 55.36, 55.37, 55.44, 55.46, 71.42, 114.26, 119.12, 123.04, 124.37, 125.00, 126.87, 128.02, 129.73, 131.21, 147.17, 151.45, 159.94, 160.44, 165.45; HRMS m/z calcd for C23H22NaO6, 417.1332 (M+Na). found, 417.1332.

1. concentrationThe reaction mixture was concentrated in vacuo
2. filtrationThe white solid was filtered
3. washwashed with hexane
4. customwas recrystallised from EtOAc/hexanes