(S)-3-((4-(hydroxymethyl)-1H-indazol-5-yl)methyl)-dihydrofuran-2(3H)-one (70 mg, 0.28 mmol), was dissolved in dichloromethane (1.5 mL). Thionyl chloride (500 μL) was added to the mixture. Reaction stirred at room temperature for 45 minutes. Mixture was concentrated. Residue was treated with dichloromethane and re-concentrated. Residue was dissolved in acetonitrile (3 mL). Potassium carbonate (150 mg, 1.1 mmol) was added to the mixture followed by neopentylamine (100 μL, 0.85 mmol). Mixture was heated at reflux for 45 minutes. Mixture was cooled to room temperature and filtered. Filtrate was concentrated in vacuo. Residue was dissolved in toluene (5 mL). Acetic acid (200 μL) was added to the mixture. Reaction was heated at reflux for 5.5 hours. Mixture was concentrated in vacuo. Preparatory HPLC purification gave the title compound as yellow solid in 19% yield. MS m/e (M−H)−=356.
