反应详情

温度

140 °C

To a solution of 6-chloro-5-bromo-pyridine-2-carboxylic acid (CAN 959958-25-9, 1.7 g, 7.19 mmol) in DMF (90 mL) and THF (30 mL) was added potassium tert-butoxide (2.02 g, 18.0 mmol) and 2,2,3,3,3-pentafluoropropan-1-ol (5.73 mL, 57.5 mmol). The mixture was stirred at 140° C. for 4 days, cooled and poured into ice-water (100 mL). 2 M Hydrochloric acid (15 mL) was added to adjust the pH to 2-3 and the mixture was extracted with TBME, organic layers were washed twice with water, pooled, dried with Na2SO4, filtered and concentrated in vacuo. The crude material was purified by flash chromatography (silica gel, ethyl acetate/n-heptane gradient) to give the title compound (548 mg, 22%) as light-brown solid; LC-MS (UV peak area, ESI) 100%, 347.9306 [M−H−].

1. temperaturecooled
2. extractionthe mixture was extracted with TBME, organic layers
3. washwere washed twice with water
4. dry with materialdried with Na2SO4
5. filtrationfiltered
6. concentrationconcentrated in vacuo
7. customThe crude material was purified by flash chromatography (silica gel, ethyl acetate/n-heptane gradient)