反应详情

To a mixture of L-tyrosine ethyl ester hydrochloride (55.08 g) and NaHCO3 (22.52 g) in CH2Cl2/H2O (280 ml/280 ml) was added di-tert-butyl bicarbonate (56.82 g) portionwise. The mixture was stirred for 2 hours at room temperature and diluted with AcOEt. The organic layer was washed with H2O, dried (Na2SO4) and evaporated. The residue was recrystallized from a mixture of diethyl ether and hexane to yield N-(tert-butoxycarbonyl)-L-tyrosine ethyl ester (62.71 g). mp. 87-88° C.; MS(APCI) m/z 327(M+NH4), 310(M+H).

1. washThe organic layer was washed with H2O
2. dry with materialdried (Na2SO4)
3. customevaporated
4. customThe residue was recrystallized from a mixture of diethyl ether and hexane