Acetic Acid → (3S,4S)-3-amino-4-[(S)-3-(4-fluorobenzyl)-piperidin-1-ylmethyl]-pyrrolidine-1-carboxylic acid tert-butyl ester

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Reaction Steps

(3S,4R)-3-Amino-4-[(S)-3-(4-fluorobenzyl)-piperidine-1-carbonyl]-pyrrolidine-1-carboxylic acid tert-butyl ester (75 mg, 185 μmol) was treated with borane-tetrahydrofuran complex in tetrahydrofuran (1.0 M; 7.4 mL, 7.4 mmol) and stirred for 20 h . The mixture was treated slowly with 20% acetic acid in methanol (10 mL), and the resulting mixture was stirred at room temperature for 1 h . The solvents were removed, and the residue was dissolved in water, made basic (pH 11) with 50% sodium hydroxide, and extracted with methylene chloride. The combined organic phases were dried (Na2SO4) and concentrated. The residue was purified by flash column chromatography (5% methanol/dichloromethane) to provide the product (30 mg, 40%). 1H NMR (300 mHz, CD3OD) δ7.20 (m, 2H), 6.98 (m, 2H), 3.18-2.42 (15H), 1.80-1.50 (4H), 1.41 (s, 9H); mass spec. (ES+) m/z 392.4.

Provenance & Evidence