Methanol → Ac-Dap(Boc)-OH

Participants

Reaction Conditions

Reaction Steps

To a solution of N-(t-butoxycarbonyl)-2(S)-benzyloxycarbonylamino-β-alanine (6.15 g) in methanol (120 ml) was added 10% Pd—C (50% wet, 1.2 g). The mixture was stirred vigorously, and hydrogen gas was bubbled for 1 hour. The catalyst was removed by filtration, and the filtrate was evaporated in vacuo. The residue was dissolved in tetrahydrofuran (70 ml) and cooled to 0° C. with ice bath. 1N NaOH (36 ml) was added, then acetic anhydride (3.77 ml) was added dropwise under stirring. The mixture was stirred for additional 1 hour at 0° C., then the pH of the mixture was adjusted to 2.5 with aqueous 20% KHSO4. The resultant mixture was extracted with ethyl acetate-tetrahydrofuran (200 ml-100 ml) twice times. The combined organic layer was dried over Na2SO4 and evaporated in vacuo. The residue was recrystallized from diethyl ether to give N-(t-butoxycarbonyl)-2(S)-acetylamino-β-alanine (3.17 g).

Provenance & Evidence