Lithium Hydroxide → 4-({(2S,5R)-1-(tert-butoxycarbonyl)-5-[(R)-{[tert-butyl(dimethyl)silyl]oxy}(pyridin-3-yl)methyl]pyrrolidin-2-yl}methyl)benzoic acid

Participants

Reaction Steps

To a stirred solution of the title compound from Step D (2.5 g, 4.6 mmol) in methanol/water 4:1 (30 mL) was added lithium hydroxide (533 mg, 23.1 mmol). The resulting mixture was stirred at RT overnight. The mixture was diluted with water and extracted with ether. The aqueous layer was acidified with 1N citric acid to PH 4.5, and then extracted with ethyl acetate. The organic layer was separated and washed with water, brine, dried over Na2SO4, and concentrated. The residue was purified by reverse phase HPLC (Luna10u, 250×50 mm I.D.; 45-65% 0.1% trifluoroacetic acid in acetonitrile/0.1% trifluoroacetic acid in water gradient) to afford 1.31 g (74%) of the title compound (i-3) as a white solid. 1H NMR (400 MHz, CDCl3): δ 8.64 (s, 2H), 7.93 (d, J=7.8 Hz, 2H), 7.80 (s, 1H), 7.44-7.38 (m, 1H), 7.03 (s, 2H), 5.66-5.33 (m, 1H), 4.16 (s, 1H), 4.00-3.88 (m, 1H), 3.01-2.95 (m, 1H), 2.68-1.58 (m, 1H), 2.04-1.83 (m, 2H), 1.60 (s, 9H), 1.31-1.20 (m, 2H), 0.96 (s, 9H), 0.17 (s, 3H), 0.00 (s, 3H). MS: m/z (ESI) 527 (M+1).

Provenance & Evidence