Dimethylformamide → 3-{[tert-Butyl(dimethyl)silyl]oxy}-5-ethyl-2-fluorobenzaldehyde

HRID 2105013Notes

Reaction equation

[C:1]([Si:5]([O:8][C:9]1[CH:14]=[C:13]([CH2:15][CH3:16])[CH:12]=[CH:11][C:10]=1[F:17])([CH3:7])[CH3:6])([CH3:4])([CH3:3])[CH3:2].CN(CCN(CCN(C)C)C)C.[Li]CCCC.CN([CH:38]=[O:39])C>C1COCC1>[Si:5]([O:8][C:9]1[C:10]([F:17])=[C:11]([CH:12]=[C:13]([CH2:15][CH3:16])[CH:14]=1)[CH:38]=[O:39])([C:1]([CH3:4])([CH3:3])[CH3:2])([CH3:7])[CH3:6]

Participants

Conditions

Temperature: -40 °C

Procedure

To a solution of Intermediate 188.2 (7.50 g, 29.5 mmol) and PMDTA (6.5 mL, 31.1 mmol) in 30 mL THF at −78° C., was added BuLi (1.4 M in hexanes, 23.2 mL, 44.3 mmol). The thick slurry was stirred at −40° C. for 30 min, was recooled to −70° C. DMF (4.57 mL, 59 mmol) was added. The yellow solution was removed from the cooling bath and allowed to warm to rt and stirred 1 h. The reaction was quenched with sat. NH4Cl, then was diluted with hexanes. The organic phase was washed with H2O (3×) and brine, dried (Na2SO4), filtered through 2″ silica gel (eluting with 5% EtOAc/hexanes), then concentrated to afford 8.03 g of Intermediate 188.3 as a pale yellow oil.

Workup

customwas recooled to −70° C
customThe yellow solution was removed from the cooling bath
temperatureto warm to rt
stirringstirred 1 h
customThe reaction was quenched with sat. NH4Cl
additionwas diluted with hexanes
washThe organic phase was washed with H2O (3×) and brine
dry with materialdried (Na2SO4)
filtrationfiltered through 2″ silica gel (eluting with 5% EtOAc/hexanes)
concentrationconcentrated

Sources & evidence

ORD record: ord-53b1e54ebaf0433abbb0b165d26ca402
Source dataset: uspto-grants-2009_08
DOI: 10.6084/m9.figshare.5104873.v1
Patent number: US07576098B2

Reaction notes

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