1-Formylazulene (1 mmol) was dissolved in 20 mL ethanol. 223 mg 1-benzylindolin-2-one (1 mmol) and 20 mL ethanol were then added. Next, a 2 mL solution (1 mmol) containing 1M pyrrolidine and ethanol was added to react at room temperature for three days. After removal of solvent, the resulting solution was extracted by 150 mL ethyl acetate and 50 mL water. The resulting solution was extracted again by 50 mL citric acid aqueous solution and ethyl acetate. The ethyl acetate layer was collected, dried with anhydrous magnesium sulfate, filtered, and concentrated under vacuum. Next, methanol was added and ultrasonically shaken at 40° C. for 1 hour. After filtration, washing by methanol, and drying, Compound 002 (315 mg, 87%) was obtained.
