1,2-Dibromoethane → 2-(Tert-butyldimethylsilyloxy)-1-(3-fluorophenyl)ethanone
Reaction equation
[Mg].Br[C:3]1[CH:8]=[CH:7][CH:6]=[C:5]([F:9])[CH:4]=1.BrCCBr.[Si:14]([O:21][CH2:22][C:23](N(OC)C)=[O:24])([C:17]([CH3:20])([CH3:19])[CH3:18])([CH3:16])[CH3:15]>>[Si:14]([O:21][CH2:22][C:23]([C:3]1[CH:8]=[CH:7][CH:6]=[C:5]([F:9])[CH:4]=1)=[O:24])([C:17]([CH3:20])([CH3:19])[CH3:18])([CH3:16])[CH3:15]Participants
Conditions
- Temperature
- -78 °C
Procedure
To a suspension of magnesium turnings (2.10 g, 85.7 mmol) in anhydrous THY (120 mL), was added slowly at RT 1-bromo-3-fluorobenzene (10.0 g, 57.2 mmol) and 1,2-dibromoethane (0.10 mL). After stirring for 40 min under argon, the mixture was cooled to −78° C., and 2-(tert-butyldimethylsilyloxy)-N-methoxy-N-methylacetamide (9.3 g, 40 mmol) was added. The resulting mixture was warmed to 0° C. and stirred for 2 h. The reaction was quenched with saturated NH4Cl (5.0 mL), and the insoluble material was filtered. The filtrate was dried (Na2SO4), filtered and concentrated in vacuo. The residue was purified by SiO2 chromatography eluting with petroleum ether/EtOAc (20:1) to afford 10.3 g (93%) of 2-(tert-butyldimethylsilyloxy)-1-(3-fluorophenyl)ethanone (58a) as oil. LCMS (ESI) m/z: 268.0[M+H]+.
Workup
- temperatureThe resulting mixture was warmed to 0° C.
- stirringstirred for 2 h
- customThe reaction was quenched with saturated NH4Cl (5.0 mL)
- filtrationthe insoluble material was filtered
- dry with materialThe filtrate was dried (Na2SO4)
- filtrationfiltered
- concentrationconcentrated in vacuo
- customThe residue was purified by SiO2 chromatography
- washeluting with petroleum ether/EtOAc (20:1)
Sources & evidence
- ORD record
- ord-bc25eb049de14897832a73fd8b2b1c7d
- Source dataset
- uspto-grants-2016_07
- Patent number
- US09388171B2
Reaction notes
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