Potassium Carbonate → HCID 90457512, compound

Participants

Reaction Steps

To a solution of (S)-2-amino-3-(3-bromo-4-hydroxyphenyl)propanoic acid, hydrobromide (3 g, 8.80 mmol) in 1,4-Dioxane (12 mL) and Water (48 mL) was added potassium carbonate (4.86 g, 35.2 mmol) followed by (9H-fluoren-9-yl)methyl carbonochloridate (2.276 g, 8.80 mmol) at 0° C. The mixture was stirred at RT for 18 hrs and then treated with water (50 mL). The resulting mixture was extracted with diethyl ether (2×15 ml). The aqueous phase was acidified with aq. HCl (1M) to pH 2-3, and extracted with DCM (3×20 ml). The combined organic layers were dried over MgSO4 and concentrated to give the crude product. The crude product was purified via silica gel chromatography (120 g column, 30-90% EtOAc:Hexanes, 20 column volumes) to give the product (S)-2-((((9H-fluoren-9-yl)methoxy)carbonyl)amino)-3-(4-((((9H-fluoren-9-yl)methoxy)carbonyl)oxy)-3-bromophenyl)propanoic acid (3.42 g, 55.2% yield) as a light yellow solid. 1H NMR (400 MHz, chloroform-d) d 7.80 (t, J=7.9 Hz, 4H), 7.68 (d, J=7.6 Hz, 2H), 7.60 (d, J=7.3 Hz, 2H), 7.49-7.32 (m, 9H), 7.16 (br. s., 2H), 5.32 (s, 1H), 4.73 (br. s., 1H), 4.58 (d, J=7.3 Hz, 2H), 4.54-4.34 (m, 2H), 4.24 (t, J=6.6 Hz, 1H), 3.31-3.03 (m, 2H). ESI-MS (+) m/z=721 (M+H2O).

Provenance & Evidence