Boc-Phe直接买,很便宜。
如果要自己做的话, To a suspension of Phe in H2O and THF (5:1, Concentration about 0.5 M)at 0 degree were added NaOH (2.0 eq.) and Boc2O (1.2 eq.). The mixture was stirred at rt for several hours (overnight is OK). The resulting mixture was diluted with H2O and washed with ether (remove Boc2O) ,and aqueous phase acidify with HCl (aq.), extracted with EtOAc (3*) and washed with brine. Concentration gave the crude product. It is so pure that you can use it without further purification. Most of time you got viscous oil. If you want to obtain crystal, you can crystallize it with EtOAc and hexanes.