Diisopropylethylamine → (R)-2-(((Benzyloxy)carbonyl)amino)-3-mercapto-3-methylbutanoic acid

Beteiligte Stoffe

Reaktionsschritte

To a round bottom flask was added (R)-2-amino-3-mercapto-3-methylbutanoic acid (5.06 g, 33.9 mmol), N-(benzyloxycarbonyloxy)succinimide (8.87 g, 35.6 mmol), MeOH (50 mL) followed by DIPEA (11.9 mL, 67.8 mmol). The reaction was stirred at rt for 1 hr. The reaction was concentrated and the residue was diluted with EtOAc (120 mL). The organics was washed with water (2×50 mL) and saturated aqueous NaCl (50 mL). The organic layer was separated, dried over MgSO4, filtered and concentrated to give (R)-2-(benzyloxycarbonylamino)-3-mercapto-3-methylbutanoic acid (4.78 g, 16.9 mmol, 49.7% yield) as a clear oil. Anal. Calcd. for C13H17NO4S m/z 283.3. found: 282.3 (M−H)+; 1H NMR (500 MHz, CDCl3) δ ppm 7.45-7.30 (m, 5H), 6.09-5.84 (m, 1H), 5.20-5.01 (m, 2H), 4.37-4.18 (m, 1H), 1.53 (br. s., 3H), 1.39 (br. s., 3H); 13C NMR (126 MHz, CDCl3) δ ppm 156.43, 136.49, 128.44, 128.28, 128.02, 53.12, 41.51, 30.83, 29.72, 11.64.

Herkunft & Nachweise