反应详情

To a solution of 1-(4-chloro-3-fluorophenyl)ethanone (3.4 g, 19.7 mmol), prepared in the previous step, in methylene chloride:methanol (1:3) was added tetrabutylammonium tribromide (9.5 g, 19.7 mmol) in portions. The reaction was monitored by TLC (3:1 hexane:ethyl acetate) until the starting material was consumed. The reaction solution was concentrated in vacuo and the residue was partitioned between diethyl ether and water. The layers were separated and the organic layer was dried over anhydrous sodium sulfate, filtered and concentrated in vacuo to give 4.2 g of crude product. The crude product was purified on silica gel using 5% ethyl acetate:hexane to give 2-bromo-1-(4-chloro-3-fluoro-phenyl)-ethanone (3.4 g, 69%) as desired product, MS (ES) m/z 252 [M+H+].

1. customwas consumed
2. concentrationThe reaction solution was concentrated in vacuo
3. customthe residue was partitioned between diethyl ether and water
4. customThe layers were separated
5. dry with materialthe organic layer was dried over anhydrous sodium sulfate
6. filtrationfiltered
7. concentrationconcentrated in vacuo
8. customto give 4.2 g of crude product
9. customThe crude product was purified on silica gel using 5% ethyl acetate