3.2.2. Synthesis of Acetyl-4′-methylalpinumisoflavone (6) A solution of 4′-O-methylalpinumisoflavone (5) (253 mg, 0.72 mmol) in 20 mL of acetic anhydride was refluxed for 120 min. After the reflux, a solution of sodium bicarbonate (10 g, 119 mmol) in 100 mL of water was added ...