To a solution of methyl 1-(4-((2R,3S,4R,5S)-3-(3-chloro-2-fluorophenyl)-4-(4-chloro-2-fluorophenyl)-4-cyano-5-neopentylpyrrolidine-2-carboxamido)phenyl)pyrrolidine-2-carboxylate (61.2 mg, 0.091.4 mmol, example 11) in THF (4.00 ml) was added a solution of LITHIUM HYDROXIDE monohydrate (22.6 mg, 0.539 mmol) in Water (2.00 ml) dropwise. The reaction mixture was stirred at rt for 2 hrs before it was neutralized with 1N HCl. it was then diluted with EtOAc, washed with water (2×10 mL), brine (2×10 mL), dried and evaporated to give 1-(4-((2R,3S,4R,5S)-3-(3-chloro-2-fluorophenyl)-4-(4-chloro-2-fluorophenyl)-4-cyano-5-neopentylpyrrolidine-2-carboxamido)phenyl)pyrrolidine-2-carboxylic acid as a white solid. MS (ES+) m/z Calcd: [(M+H)+]: 655. found: 655.
