反应详情

Methyl (E)-4-[2-(H-indazol-3-yl)vinyl]benzoate (0.71 g, 2.54 mmol) obtained in Step 5 was dissolved in methanol (2.6 mL), and the solution was added with an aqueous sodium hydroxide solution (1 mol/L, 5.00 mL), followed by heating under reflux for 1.5 hours. Methanol was evaporated under reduced pressure, the pH of the residue was adjusted to 3 or below with 6 mol/L hydrochloric acid under ice-cooling. The resulting precipitates were collected by filtration to obtain (E)-4-[2-(1H-indazol-3-yl)vinyl]benzoic acid (0.70 g, quantitative yield).

1. temperatureby heating
2. temperatureunder reflux for 1.5 hours
3. customMethanol was evaporated under reduced pressure
4. temperaturecooling
5. customThe resulting precipitates
6. filtrationwere collected by filtration