Ammonium formate → t-butyl (2S)-2-(n-butylsulphonylamino)-3-(4-aminophenyl)propionate

Participants

Reaction Steps

To a solution of the product of step (b) (2.9 g) and ammonium formate (1.90 g) in methanol (30 ml) under argon was added 10% Pd on C (450 mg). The reaction mixture was stirred at ambient temperature for 6 hours then the catalyst was filtered off using a pad of diatomaceous earth which was washed with methanol (30 ml). The combined filtrate and washings were evaporated to dryness and the residue was partitioned between ethyl acetate (50 ml) and dilute NaHCO3 (aq.) (50 ml). The organic layer was separated, washed with water, dried (MgSO4) and evaporated to yield a residue which slowly solidified to give t-butyl (2S)-2-(n-butylsulphonylamino)-3-(4-aminophenyl)propionate (2.59 g) as an off-white solid: NMR Spectrum (CDCl3) 0.90 (3H, t), 1.36 (2H, m), 1.45 (9H, s), 1.67 (2H, m), 2.77 (2H, m), 2.93 (2H, m), 3.62 (2H, br s), 4.16 (1H, m), 4.68 (1H, d), 6.61 (2H, d), 6.99 (2H, d); Mass Spectrum m/Z 379 (M+Na)+.

Provenance & Evidence