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

(3S,4S)-3-[(S)-3-(4-Fluorobenzyl)-piperidin-1-ylmethyl]-4-[(R)-1-phenyl-ethylamino]-pyrrolidine-1-carboxylic acid tert-butyl ester (100 mg, 0.201 mmol), palladium hydroxide (20 weight % on carbon, dry basis; 40 mg) and methanol (7 mL) were combined in a pressure bottle and shaken under hydrogen atmosphere (50-55 psig) for 20 h. The mixture was filtered through Celite, and the solids were rinsed with ethanol. The filtrate was concentrated to give the product as a glassy foam (75 mg, 95%), used without further purification.