Sulfuric Acid → 2-(5-Fluoro-2-methoxyphenyl)acetaldehyde

Temperature

0 °C

To a suspension of methoxymethyltriphenylphosphonium chloride (10.0 g, 30.0 mmol) in THF (30 mL) under Ar was added NaH (60% in mineral oil, 1.2 g, 30 mmol) and then heated to reflux for 1 h. The orange colored suspension was cooled to 0° C. and 5-fluoro-2-methoxybenzaldehyde (4.2 g, 26.0 mmol) was added and the mixture was stirred for 12 h at room temperature. The reaction mixture was then poured into a separatory funnel containing ammonium chloride aqueous solution (sat. NH4Cl/H2O, 1:1, v:v, 100 mL). The organic material was extracted with ethyl acetate (3×80 mL) and the combined organic layers were washed with brine (60 mL) and dried over Na2SO4. The solvent was then removed in vacuo and the crude product (2a) obtained was dissolved in acetone (50 mL). H2SO4 (1 M, 1.5 mL) was then added and the mixture obtained was heated to reflux for 6 h while stirring. The reaction was then cooled to room temperature and the solvent was removed in vacuo to obtain the crude product that was then purified by flash column chromatography (Rf=0.15, EtOAc/Hexane, 10:90, v:v) to afford the product (2.63 g, 66%) as an oil: 1H NMR (CDCl3, 500 MHz): δ 9.68 (s, 1 H), 6.97 (dt, J=3.1, 8.7 Hz, 1 H), 6.89 (dd, J=3.1, 8.7 Hz, 1 H), 6.83 (dd, J=4.3, 8.7 Hz, 1 H), 3.80 (s, 3 H), 3.63 (d, J=1.7 Hz, 2 H).

1. temperatureheated
2. temperatureto reflux for 1 h
3. additionThe reaction mixture was then poured into a separatory funnel
4. extractionThe organic material was extracted with ethyl acetate (3×80 mL)
5. washthe combined organic layers were washed with brine (60 mL)
6. dry with materialdried over Na2SO4
7. customThe solvent was then removed in vacuo
8. customthe crude product (2a) obtained
9. customthe mixture obtained
10. temperaturewas heated
11. temperatureto reflux for 6 h
12. stirringwhile stirring
13. temperatureThe reaction was then cooled to room temperature
14. customthe solvent was removed in vacuo
15. customto obtain the crude product that
16. customwas then purified by flash column chromatography (Rf=0.15, EtOAc/Hexane, 10:90, v:v)

ORD record

ord-646f11a98ee34b6d8539ff386da9ffa4

Source dataset

uspto-grants-2012_05

DOI

10.6084/m9.figshare.5104873.v1

Patent number

US08168635B2