Sulfuric Acid → 3-Cyano-4-fluorobenzoic acid

Participants

Reaction Steps

Chromium oxide (14.77 mmol; 1.48 g) was dissolved in a solution of sulfuric acid (1.1 mL) and water (3.4 mL) at 0° C. To this solution was added to a mixture of 3-cyano-4-fluorobenzaldehyde (13.4 mmol; 2.0 g) in acetone (17 mL) at 0° C. The reaction mixture was warmed to rt and stirred for 6 h. The reaction was then quenched with methanol (20 mL) and water (50 mL) and the product was extracted with EtOAc (2×50 mL). The combined organics were washed with brine (50 mL), dried over magnesium sulfate, filtered and concentrated in vacuo to yield 2.25 g of product: 1H NMR (500 MHZ, CDCl3) δ 8.39 (d, J=5.0, 1H), 8.28-8.29 (m, 1H), 7.64 (t, J=8.9, 1H).

Provenance & Evidence