Hydrochloric Acid → 4-Fluoro-2-hydroxybenzaldehyde

Participants

Reaction Steps

To the mixture of 3-fluorophenol (10 mL, 102 mmole), anhydrous magnesium chloride (28.2 g, 744.6 mmole) in 500 mL of anhydrous acetonitrile was added anhydrous triethylamine (67 mL, 382.5 mmole) and paraformaldehyde (22.3 g, 744.6 mmole). The mixture was then heated to reflux for five hours. After cooling to r.t, 500 mL of 5% aqueous hydrochloric acid was added. The product was extracted with ethyl acetate. The combined organic extracts were washed with 5% hydrochloric acid (×3), brine, and dried over anhydrous magnesium sulfate. After removing the volatiles, the residue was a light pink solid. 11 g, yield 72%. M.P: 67.5-69.0° C. ESHRMS m/z 139.0211(M−H, C7H4FO2 calc'd 139.0201). 1H NMR (CDCl3/300 MHz) 11.40 (s, 1H), 9.86 (s, 1H), 7.62-7.57 (m, 1H ), 6.79-6.67 (m, 2H). 3C (CDCl3/300 MH) 195.4, 168.3 (d, J=258 Hz), 164.4 (d, J=14.9 Hz), 136.3 (d, J=12.6 Hz), 118.2 (d, J=2.0 Hz), 108.5 (d, J=23.3 Hz), 104.9 (d, J=24.4 Hz). 19F (CDCl3/400 MHz) −97.9 (m).

Provenance & Evidence