反应详情

Add tetrakis(triphenylphosphine)palladium(0) (500 mg) to a degassed suspension of 4-bromo-1H-imidazole (5.0 g, 34 mmol) and 2-isopropoxyphenyl boronic acid (9.19 g, 51 mmol) in dioxane (250 mL) and 2 M sodium carbonate solution (10.81 g, 102 mmol) at room temperature under nitrogen and heat the mixture at reflux for 21 hours. Remove the solvent under reduced pressure, dilute the residue with ethyl acetate (500 mL) and filter through a plug of Celite. Dry the filtrate over sodium sulfate, treat with silica gel (20 g) and remove the solvent under reduced pressure. Purify the residue by flash column chromatography on silica gel, eluting with ethyl acetate, to afford crude 4-(2-isopropoxyphenyl)-1H-imidazole (5.01 g, 73%) which is used without further purification in the next step.

1. temperatureheat the mixture
2. temperatureat reflux for 21 hours
3. customRemove the solvent under reduced pressure
4. additiondilute the residue with ethyl acetate (500 mL)
5. filtrationfilter through a plug of Celite
6. dry with materialDry the filtrate over sodium sulfate
7. additiontreat with silica gel (20 g)
8. customremove the solvent under reduced pressure
9. customPurify the residue by flash column chromatography on silica gel
10. washeluting with ethyl acetate