Dimethylformamide → 2,4-Difluoro-3-formylbenzoic acid

HRID 79025

Reaktionsgleichung

CN(CCN(C)C)C.C([Li])(CC)C.[F:14][C:15]1[CH:23]=[C:22]([F:24])[CH:21]=[CH:20][C:16]=1[C:17]([OH:19])=[O:18].CN([CH:28]=[O:29])C>C1COCC1>[F:14][C:15]1[C:23]([CH:28]=[O:29])=[C:22]([F:24])[CH:21]=[CH:20][C:16]=1[C:17]([OH:19])=[O:18]

Komponenten

Reaktionsbedingungen

Temperatur: -75 °C

Versuchsvorschrift

A solution of TMEDA (10.5 mL, 70 mmol) in THF (50 mL) was cooled to <−80° C. and treated with sec-butyllithium (50 mL, 70 mmol). A solution of 2,4-difluorobenzoic acid (5.0 g, 31.6 mmol) in THF was added dropwise maintaining the temperature below −80° C. The reaction mixture was allowed to warm to −75° C. and treated with DMF (15 mL), the mixture then allowed to warm to 0° C. before quenching the reaction with water. The aqueous layer was separated, acidified to pH ˜2 (concentrated HCl) and extracted twice with diethyl ether. The combined organic extracts were dried (Na2SO4), filtered and concentrated in vacuo to give a yellow oil. The crude product was crystallized from cyclohexane/diethyl ether to give the title compound as a yellow solid (670 mg, 11%). 1H NMR (CDCl3, 400 MHz) 10.40 (1 H, s), 8.31 (1 H, ddd, J=8.96, 8.02, 6.08 Hz), 7.12 (1 H, td, J=9.09, 1.42 Hz).

Aufarbeitung

temperaturemaintaining the temperature below −80° C
temperatureto warm to 0° C.
custombefore quenching
customthe reaction with water
customThe aqueous layer was separated
extractionextracted twice with diethyl ether
dry with materialThe combined organic extracts were dried (Na2SO4)
filtrationfiltered
concentrationconcentrated in vacuo
customto give a yellow oil
customThe crude product was crystallized from cyclohexane/diethyl ether

Quellen und Nachweise

ORD-Eintrag: ord-a47cc2a286804b1e87ac2eff419cddd0
Quelldatensatz: uspto-grants-2014_09
DOI: 10.6084/m9.figshare.5104873.v1
Patentnummer: US08841462B2

Verknüpfte Notizen

Wird geladen…