反应详情

温度

130 °C

A mixture of intermediate 37 (3.6 g, 22 mmol) and 48% hydrogen iodide (30 mL) was heated to reflux (130° C.) and stirred for 12 h. The reaction mixture was neutralized to pH=8 with aq NaOH and then extracted with EtOAc. The combined organic layers were dried over anhydrous Na2SO4, concentrated under vacuum and purified by flash chromatography on silica gel column (elution with DCM/MeOH=80:1) to give 5-hydroxy-1H-benzo[d]imidazol-2(3H)-one (intermediate 38) (16.9 g, 80%). HPLC: 99%, RT 1.377 min. MS (ESI) m/z 151.0 [M+H]+. mp: 186-187° C.

1. temperaturewas heated
2. extractionextracted with EtOAc
3. dry with materialThe combined organic layers were dried over anhydrous Na2SO4
4. concentrationconcentrated under vacuum
5. custompurified by flash chromatography on silica gel column (elution with DCM/MeOH=80:1)