(S)-2-Amino-3-(6-fluoro-1H-indol-3-yl)-propionic acid → HCID 67186837, compound

Participants

Reaction Conditions

Reaction Steps

6-Fluorotryptophan (1.9 g, 9.153 mmol) was dissolved in THF (50 mL) and cooled to 0° C. in an ice bath. BH3.Me2S complex (2.55 mL, 26.87 mmol) was added and the reaction mixture was heated at reflux for 21 h. The reaction mixture was then cooled in an ice bath and cautiously quenched by the dropwise addition of MeOH (5 mL). The crude reaction mixture was then concentrated in vacuo. The crude product was dissolved in EtOAc (50 mL) and extracted with aqueous NaOH (20% w/v, 2×50 mL) after which the combined aqueous fractions were extracted with EtOAc (2×50 mL), and the combined organic fractions were washed with brine (50 mL), dried (MgSO4), filtered and concentrated in vacuo to give the title compound (2.24 g, quantitative) as a white semi-solid that was used without further purification. δH (CD3OD) 7.28 (1H, dd, J 8.9 and J 5.5 Hz), 6.85 (1H, s), 6.83 (1H, dd, J 10.0 and J 2.3 Hz), 6.57 (1H, dt, J 8.1 and J 8.6 Hz), 3.37 (1H, dd, J 10.7 and J 4.3 Hz), 3.19 (1H, dd, J 10.7 and J 6.8 Hz), 2.92 (1H, m), 2.67 (1H, dd, J 14.1 and J 5.8 Hz), 2.47 (1H, dd, J 14.3 and J 7.5 Hz). No exchangeable protons were observed. LCMS (ES+) 208.0 (M)+, RT 1.30 minutes (Method 1).

Provenance & Evidence