反应详情

Compound 22a (300 mg, 0.59 mmol) was suspended in 10 mL of ethanol. 1.5 mL of 2 M potassium hydroxide solution was added and refluxed for 1 hour. The reaction is substantially completed. 2 mL of acetic acid was added. Most of the solvent was distilled off under reduced pressure to precipitate solids. The precipitated solids were filtered to give compound 23a. White solid (224 mg, 92.6%). m.p. 244-245° C. 1H NMR (300 MHz, DMSO-d6): δ 12.54 (s, 1H), 8.37 (s, 1H), 8.11 (s, 1H), 7.34 (s, 1H), 6.83 (s, 3H), 4.00 (t, J=4.0 Hz, 4H), 3.73 (t, J=4.0 Hz, 4H). LC-MS: 409 (M+1).

1. temperaturerefluxed for 1 hour
2. distillationMost of the solvent was distilled off under reduced pressure
3. customto precipitate solids
4. filtrationThe precipitated solids were filtered