Ethyl 2-[1-[4-(6-fluoro-2-naphthamido)benzyl]-1H-indazol-3-yl]acetate (262 mg, 0.544 mmol) was dissolved in tetrahydrofuran (10 mL), and in an ice bath 10 mL aqueous solution dissolving lithium hydroxide monohydrate (114 mg, 2.71 mmol) was added. It was reacted at room temperature for 3 h, and the reaction was monitored to be complete by TLC. Water was added into the system, and adjusted to pH≈3-4 with diluted hydrochloric acid. A solid precipitated, which was filtered and dried to obtain a white solid 228 mg, at a yield of 92.5%.
