Hydrochloric Acid → 6-fluoro-7-hydroxy-3,4-dihydro-2H-1-benzopyran-4-one

Participants

Reaction Conditions

Reaction Steps

In a 15 mL vial was added 4-fluorobenzene-1,3-diol (500 mg, 3.9 mmol) and 3-chloropropanoic acid (424 mg, 3.9 mmol) and trifluoromethanesulfonic acid (2 mL). The mixture was heated to 80° C. and stirred at that temperature for 4 hour. The reaction was cooled and poured into water (10 mL). The product was extracted with ethyl acetate, dried over anhydrous Na2SO4, filtered, concentrated. To the dark red solid obtained was added sodium hydroxide (2 N, 5 mL) and the solution was let stirred at RT for 18 hours. The mixture was neutralized with 2 N HCl, extracted with EtOAc. The organic phase was dried over anhydrous Na2SO4, filtered, concentrated. The crude was used to next step without purification. 1H NMR (500 MHz, CDCl3, δ in ppm): 7.61 (1H, d, J=10.3 Hz), 6.56 (1H, d, J=3.1 Hz), 4.48 (2H, t), 2.78 (2H, t).

Provenance & Evidence