28123-73-1

5-(4-Nitrophenyl)-2-furoic acid (5-(p-nitrophenyl)-2-furoic acid) is a 5-aryl-2-furoic acid. It is a dantrolene metabolite and its presence in plasma and urine has been determined by HPLC. It was reported to be the only product formed during the reduction of 5-(4-nitrophenyl)-2-furaldehyde by modified Cannizzaro reaction.

[1] Mori, M.;Tresoldi, A.; Villa, S.;Cazzaniga, G.;Bellinzoni, M.;Meneghetti, F.5-(4-Nitrophenyl)furan-2-carboxylic Acid. Molbank 2022, 2022, M1515.

To a solution of methyl 5-(4-nitrophenyl)furan-2-carboxylate (2, 50 mg, 0.2 mmol) in a mixture of H2O (2.6 mL) and MeOH (1.3 mL) was added NaOH (24 mg, 0.6 mmol). The reaction mixture was stirred at reflux for 3 h and partially concentered in vacuo to remove the solvent; then, 1 M HCl was added to adjust the pH to 3–4. The aqueous phase was extracted with EtOAc (3 × 5 mL), the combined organic phases were dried over anhydrous Na2SO4, filtered, and evaporated under reduced pressure to obtain 5-(4-NITROPHENYL)-2-FUROIC ACID as a yellow solid.[1]