反应详情

(1H-Indazol-3-ylmethyl)triphenylphosphonium bromide (2.5 g, 5.30 mmol) was dissolved in methanol (40 mL) and the solution was added with 2-formylbenzoic acid methyl ester (954 mg, 5.80 mmol) and potassium carbonate (2.20 g, 15.8 mmol), followed by stirring at room temperature for 2.5 hours. The reaction mixture was added with water and the precipitated solid was collected by filtration. The solid was added with 2 mol/L aqueous sodium hydroxide solution (75 mL) and heated under reflux in THF (50 mL). The mixture was extracted with ethyl acetate and the aqueous layer was neutralized by 6 mol/L hydrochloric acid. The precipitated solid was collected by filtration and the obtained solid was dried to obtain (E)-2-[2-(1H-indazol-3-yl)vinyl]benzoic acid (500 mg, 36%).

1. filtrationthe precipitated solid was collected by filtration
2. additionThe solid was added with 2 mol/L aqueous sodium hydroxide solution (75 mL)
3. temperatureheated
4. temperatureunder reflux in THF (50 mL)
5. extractionThe mixture was extracted with ethyl acetate
6. filtrationThe precipitated solid was collected by filtration
7. customthe obtained solid was dried