Citric Acid → HCID 68001015, compound

Participants

Reaction Steps

2-tert-Butoxycarbonylamino-3-(1-fluorocyclopentyl)-propionic acid (200 mg, 0.73 mmol) was kept in 4M HCl in dioxane (3 mL) for 20 min The mixture was then freeze-dried and left under a vacuum for 2 h. The solid residue was dissolved in dioxane-H2O 1:1 (12 mL). NaHCO3 (2.18 mmol, 3 eq.) and then ethyl chloroformate (0.87 mmol 1.2 eq.) dissolved in of dioxane (1 mL) were added. The reaction mixture was stirred for 20 min until completed according LC-MS. The mixture was acidified by citric acid (10% aq.) to pH 5. The product was extracted with DCM (20 mL) and EtOAc (20 mL). The organic layers were combined, dried (MgSO4) and concentrated. The afforded crude was used without further purification in the next step.

Provenance & Evidence