4-bromo-2-chloro-N-methoxy-N-methylbenzamide → 1-(4-Bromo-2-chlorophenyl)ethan-1-one

Temperature

-78 °C

To a solution of 4-bromo-2-chloro-N-methoxy-N-methylbenzamide (2.27 g, 8.15 mmol) in THF at −78° C. was added methylmagnesium chloride (4.07 ml, 3M solution in THF, 12.23 mmol) dropwise. The reaction mixture was stirred at −78° C. for 1 h and then warmed to rt slowly and stirring was continued at rt overnight. The reaction mixture was quenched with 1N HCl and extracted with ether. The organic layer was washed with water, and brine, dried (MgSO4), filtered and concentrated in vacuo to give a residue which was purified by flash column chromatography (1:4 ether:pentane) to give 1-(4-bromo-2-chlorophenyl)-ethanone (1.52 g, 80%) as a yellow oil. 1H NMR (CDCl3, 300 MHz): δ 7.61 (m, 1H), 7.50-7.44 (m, 2H), 2.64 (s, 3H).

1. temperaturewarmed to rt slowly
2. stirringstirring
3. waitwas continued at rt overnight
4. customThe reaction mixture was quenched with 1N HCl
5. extractionextracted with ether
6. washThe organic layer was washed with water, and brine
7. dry with materialdried (MgSO4)
8. filtrationfiltered
9. concentrationconcentrated in vacuo
10. customto give a residue which
11. customwas purified by flash column chromatography (1:4 ether:pentane)

ORD record

ord-8c80e142df994f34859b1604e6cfded4

Source dataset

uspto-grants-2007_08

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US07259183B2