Dimethylformamide → 2-Fluoropyridine-3-carbaldehyde

Temperatur

-78 °C

A solution of 2-fluoropyridine (306 mg, 3.15 mmol) in THF (1 mL) was added to a solution of lithium diisopropylamide in THF (0.20 M, 17 mL, 3.4 mmol) at −78° C. The solution was stirred at −78° C. for 4 h, then DMF (0.73 mL, 9.4 mmol) was added dropwise and stirring was continued at −78° C. for 2.5 h. Saturated NH4Cl(aq) (2 mL) was added, and the mixture was allowed to warm to room temperature. The mixture was diluted with EtOAc (20 mL), and the organic phase was washed with saturated NaHCO3(aq) (20 mL) and brine (10 mL), then dried (MgSO4) and concentrated in vacuo. Purification of the crude material by chromatography on silica gel (10% EtOAc/hexanes) gave the title compound as a yellow liquid (58 mg, 15%). 1H NMR (CDCl3) □ 7.39 (m, 1H), 8.32 (m, 1H), 8.48 (m, 1H), 10.33 (s, 1H).

1. stirringstirring
2. waitwas continued at −78° C. for 2.5 h
3. temperatureto warm to room temperature
4. washthe organic phase was washed with saturated NaHCO3(aq) (20 mL) and brine (10 mL)
5. dry with materialdried (MgSO4)
6. concentrationconcentrated in vacuo
7. customPurification of the crude material by chromatography on silica gel (10% EtOAc/hexanes)

ORD-Eintrag

ord-ae7961b104604450beaed78f4ad54709

Quelldatensatz

uspto-grants-2006_08

DOI

10.6084/m9.figshare.5104873.v1

Patentnummer

US07084155B2