反应详情

A solution of 4.0 g (13.1 mmol) 5-hydroxy-pyrrolo[2,3-b]pyridine-1,2-dicarboxylic acid 1-tert-butyl ester 2-ethyl ester in 100 mL dichloromethane was cooled to 0° C. and 2.2 mL (1.6 g, 15.7 mmol) triethylamine and 2.6 mL (4.4 g, 15.7 mmol) trifluoromethanesulfonic acid were added. After 2 h at 0° C. the reaction was poured into 10% aqueous sodium bicarbonate solution and extracted with dichloromethane. The organic layer was washed with brine, dried over magnesium sulfate and evaporated. The residue was dissolved in 100 mL tetrahydrofuran and 0.75 g (0.65 mmol) tetrakis(triphenylphosphine)palladium (0) and 13.1 mL trimethylaluminium (2M solution in n-heptane) were added. The reaction mixture was heated to reflux for 2 h and after cooling to room temperature poured into ethyl acetate and water, filtered through speedex and extracted with ethyl acetate. The organic layer was washed with brine, dried over magnesium sulfate, filtered and evaporated. The residue was purified by column chromatography over silica gel (0.030–0.063 mm) with ethyl acetate:n-hexane (1:1) as eluant to give the product as a light yellow solid (64.5%).

1. extractionextracted with dichloromethane
2. washThe organic layer was washed with brine
3. dry with materialdried over magnesium sulfate
4. customevaporated
5. dissolutionThe residue was dissolved in 100 mL tetrahydrofuran
6. temperatureThe reaction mixture was heated
7. temperatureto reflux for 2 h
8. filtrationfiltered through speedex
9. extractionextracted with ethyl acetate
10. washThe organic layer was washed with brine
11. dry with materialdried over magnesium sulfate
12. filtrationfiltered
13. customevaporated
14. customThe residue was purified by column chromatography over silica gel (0.030–0.063 mm) with ethyl acetate:n-hexane (1:1) as eluant