Hexane → 2-Bromo-1-(4-chloro-3-fluorophenyl)ethanone

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

ORD record

ord-5080b2c6a2f24bc08863019aeb39f773

Source dataset

uspto-grants-2009_11

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07618990B2