Ethyl difluoroacetate → 1-(3-Bromophenyl)-2,2-difluoroethanone

Temperature

-78 °C

1-Bromo-3-iodo-benzene (22.5 g, 90 mmol, Aldrich) was dissolved in THF and cooled to −78° C. nBuLi (69.8 ml, 90 mmol) was added over 15 minutes and the reaction was stirred for 30 min. at −78° C. Difluoro-acetic acid ethyl ester (16.59 ml, 153 mmol, Aldrich) was added dropwise and stirring was continued for 3 hrs. After completion the reaction was quenched by the addition of 329 ml 2 M HCl solution and reaction was warmed to r.t. The phases were separated and the aqueous phases was extracted with Et2O. The organic phases were washed with water and brine, dried over Na2SO4 and concentrated under reduced pressure. The residue was purified by automated column chromatography (cyclohexane/ethyl acetate) to yield the title compound as a yellow oil. 1H-NMR (360 MHz, DMSO-d6): 8.18 (s, 1H), 8.02 (m, 2H), 7.61 (t, 1H), 7.21 (t, 1H, CHF2); GC/MS: 234 [(M+H)+].

1. additionwas added over 15 minutes
2. stirringstirring
3. waitwas continued for 3 hrs
4. customAfter completion the reaction was quenched by the addition of 329 ml 2 M HCl solution and reaction
5. temperaturewas warmed to r.t
6. customThe phases were separated
7. extractionthe aqueous phases was extracted with Et2O
8. washThe organic phases were washed with water and brine
9. dry with materialdried over Na2SO4
10. concentrationconcentrated under reduced pressure
11. customThe residue was purified by automated column chromatography (cyclohexane/ethyl acetate)

ORD record

ord-54010251e3e34db284e10f1a76c49ad6

Source dataset

uspto-grants-2012_06

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08207164B2