To a solution of 7-(2,4-dichlorophenylamino)-8-fluoro-4-methyl-cinnoline-6-carboxylic acid methyl ester (54 mg, 0.14 mmol) in THF-water (3 mL/l mL) was added 1 N aqueous LiOH (0.30 mL, 0.30 mmol) at room temperature. After 30 minutes, the reaction mixture was adjusted to pH 6-7 with 1 N aqueous HCl, diluted with water, and extracted with EtOAc-THF. The organic layer was washed with water, dried over MgSO4, filtered, and concentrated in vacuo to give 31 mg (60%) of the crude product (31 mg, 60%), which was used directly without further purification.
