Hydrochloric Acid → (S)-2-{(R)-2-Amino-4-[(R)-3-(cyclohexylmethyl-hydroxy-phosphinoyl)-2-hydroxy-propylcarbamoyl]-butyrylamino}-propionic acid

Participants

Reaction Steps

4N HCl in dioxane (5 mL) was added to (S)-2-{(R)-2-tert-butoxycarbonylamino-4-[(R)-3-(cyclohexylmethyl-hydroxy-phosphinoyl)-2-hydroxy-propylcarbamoyl]-butyrylamino}-propionic acid tert-butyl ester (0.351 g, 0.592 mmol) in water (1 mL). The resulting colorless solution was stirred under N2 at rt overnight. The reaction mixture was concentrated in vacuo and the residue was purified by RP-HPLC eluting in a gradient of 10% CH3CN/H2O (adjusted with HCl pH=3.5) to 100% CH3CN over 20 min at 45 mL/min. The appropriate fractions were combined and lyophilized to give the title compound (0.096 g, 0.220 mmol) as a white solid. 1H NMR (CD3OD, 300 MHz): δ 4.38 (q, J=7.2 Hz, 1H), 4.04 (m, 1H), 3.90 (t, J=6.3 Hz, 1H), 3.35 (dd, J=5.7, 13.2 Hz, 1H), 3.21 (dd, J=5.7, 13.5 Hz, 1H), 2.41 (m, 2H), 2.11 (m, 2H), 1.92 (br d, 2H), 1.77-1.65 (m, 6H), 1.52 (dd, J=6.3, 13.5 Hz, 2H), 1.43 (d, J=7.2 Hz, 3H), 1.37-1.15 (m, 3H), 1.08-1.00 (m, 2H). 31P NMR (CD3OD, 300 MHz): δ 42.95. LCMS m/z: [M+H]+=436.25

Provenance & Evidence