Lithium Hydroxide → 2-(4-((2S,4R)-1-acetyl-4-((isopropoxycarbonyl)amino)-2-methyl-1,2,3,4-tetrahydroquinolin-6-yl)phenyl)acetic acid

Lithium hydroxide (4N in water, 1 mL, 4.00 mmol) was added to a solution of ethyl {4-[(2S,4R)-1-acetyl-2-methyl-4-({[(1-methylethyl)oxy]carbonyl}amino)-1,2,3,4-tetrahydro-6-quinolinyl]phenyl}acetate (for a preparation see Intermediate 100) (32.6 mg, 0.072 mmol) in methanol (3 mL). The resulting mixture was stirred under nitrogen at room temperature for 12 h then most of the solvent was removed in vacuo. The residue was partitioned between AcOEt (30 mL) and water (15 mL) and the layers were separated. The aqueous phase was extracted with AcOEt (15 mL). The combined organic phases were washed with brine (20 mL), dried over MgSO4 and concentrated in vacuo. Purification of the residue by MDAP (modifier: formic acid) gave {4-[(2S,4R)-1-acetyl-2-methyl-4-({[(1-methylethyl)oxy]carbonyl}amino)-1,2,3,4-tetrahydro-6-quinolinyl]phenyl}acetic acid (23.8 mg, 0.056 mmol, 78%) as a white solid.