反应详情

To a round bottomed flask were added 2-chloro-3-bromothiophene (26.2 g, 132.7 mmole) along with diethyl ether (390 mL). The reaction was cooled to -78° C. (dry ice/acetone) and 1.6M n-butyllithium (87.0 mL, 139.0 mmole) was added dropwise. The reaction was stirred for 1.5 hours after which an excess of CO2 (~25.0 g) was added all at once. The reaction was warmed to room temperature and poured onto ice/water. The mixture was extracted with 10% sodium carbonate solution and the basic aqueous layer was washed with methylene chloride. The basic solution was then acidified to a pH 3.0 and extracted with diethyl ether. The organic layer was washed with water, brine, and dried (MgSO4). Solvent removal yielded 19.32 g of an off-white solid (90%) which was used as is.

1. additionwas added dropwise
2. additionwas added all at once
3. additionpoured onto ice/water
4. extractionThe mixture was extracted with 10% sodium carbonate solution
5. washthe basic aqueous layer was washed with methylene chloride
6. extractionextracted with diethyl ether
7. washThe organic layer was washed with water, brine
8. dry with materialdried (MgSO4)
9. customSolvent removal