Ammonium Hydroxide → N-Acetylcysteine amide

Participants

Reaction Steps

45a (53.4 g, 0.30 mol) was diluted with 250 mL of toluene and 200 mL of ammonium hydroxide. The mixture was stirred at room temperature overnight then concentrated. The resulting residue was suspended in 250 mL of acetonitrile/H2O (9.3:1) and stirred at room temperature until the insoluble material formed a viscous paste. The solvent was decanted then concentrated to give a viscous liquid. The crude product was taken up in dichloromethane/methanol (8.5:1) and passed through a silica gel column eluting with dichloromethane/methanol (8.5:1). Fractions containing the least polar UV-active component were combined and concentrated to give 25 g (52%) of (R)-2-acetamido-3-mercaptopropanamide as white solid. 1HNMR (DMSO-d6) δ 8.0 (d, 1H), 7.41 (s, 1H), 7.13 (s, 1H), 4.33 (m, 1H), 2.76 (m, 1H), 2.65 (m, 1H), 2.22 (m, 1H), 1.88 (s, 3H).

Provenance & Evidence