Acetic Acid → 3-[(4-Chloro-benzyl)-isobutyl-amino]-pyrrolidine-1-carboxylic acid tert-butyl ester

Participants

Reaction Steps

To a solution of 3-(4-chloro-benzylamino)-pyrrolidine-1-carboxylic acid tert-butyl ester (0.4 g, 1.28 mmol) and isobutyraldehyde (0.14 g, 1.92 mmol) in dichloroethane was added sodium triacetoxy borohydride (0.81 g, 3.85 mmol) and catalytic acetic acid. The resulting reaction mixture was stirred at room temperature overnight. The reaction mixture was concentrated, dissolved in dichloromethane and washed with saturated aqueous sodium bicarbonate. The combined organics were washed with brine and dried over sodium sulfate. The crude product was purified on silica using gradient elution from hexane/ethyl acetate (10%) to hexane/ethyl acetate (50%). 1H-NMR (CDCl3) δ: 0.80 (6H, 2×d), 1.45 (9H, s), 1.60-1.90 (2H, m), 2.20 (2H, d), 3.00-3.70 (7H, m), 7.20 (4H, s). ESI-MS m/z: 367 (M+1), UV retention time: 1.89 min.

Provenance & Evidence