Carbon Dioxide → ethyl (S)-2-tert-butoxycarbonylamino-3-(4-but-2-ynyloxy-phenyl)-propionate

Participants

Reaction Steps

In dehydrated DMF (5.0 mL) was dissolved 1.35 g (4.23 mmol) of Boc-L-tyrosine ethyl ester (AK Scientific, Inc catalogue No 71054), and anhydrous potassium carbonate (0.7 g, 5.08 mmol) and 1-bromo-2-butyne (0.619 g, 4.65 mmol) were added at room temperature. The mixture was stirred under argon atmosphere for 21 hours. Subsequently, a saturated aqueous solution of ammonium chloride was added to the reaction solution until generation of carbon dioxide gas stopped. This reaction solution was extracted with ethyl acetate, and washed with water and a saturated brine in this order. The extracted organic layer was dried over anhydrous sodium sulfate. The solvent was then distilled off under reduced pressure. The obtained oily residue was purified by silica gel chromatography (20 g cartridge was used) using 10% ethyl acetate/n-hexane as an elution solvent to obtain 1.47 g (92% yield) of the title compound as clear and colorless oil.

Provenance & Evidence