6-Methylsalicylic Acid → 3-Bromo-6-hydroxy-2-methylbenzoic acid

Beteiligte Stoffe

Reaktionsbedingungen

Reaktionsschritte

Step 2 A suspension of 2-hydroxy-6-methylbenzoic acid (1.32 g, 8.68 mmol) in acetonitrile (20 mL) at −20° C. was treated with tetrafluoroboric acid dimethyl ether complex (1.109 mL, 9.11 mmol), followed by portionwise addition of N-bromosuccinimide (1.699 g, 9.54 mmol) over 30 min. The mixture was warmed to 0° C. and stirred for 1 h, then was treated with 40% aqueous sodium bisulfate (10 mL). The acetonitrile was removed under vacuum and the aqueous residue was extracted with EtOAc (3×40 mL). The combined organic layers were washed with water and brine, dried and concentrated to give 3-bromo-6-hydroxy-2-methylbenzoic acid as a white solid (1.60 g, 80%). 1H NMR (400 MHz, methanol-d4) δ 7.47 (1H, d, J=8.80 Hz), 6.67 (1H, d, J=8.80 Hz), 2.50 (3H, s). Mass spectrum m/z 231, 233 (M-1-1)−.

Herkunft & Nachweise