Sulfuric Acid → (S)-tert-Butyl 3-amino-2-(((benzyloxy)carbonyl)amino)propanoate

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Reaction Steps

The tert-butyl (S)-3-amino-2-benzyloxycarbonylaminopropionate was prepared as follows. 10 g (42 mmol) of (S)-3-amino-2-benzyloxycarbonylaminopropionic acid were shaken in a mixture of 100 ml of dioxane, 100 ml of isobutylene and 8 ml of conc. H2SO4 in an autoclave under an N2 pressure of 20 atm for 3 days. Excess isobutylene was blown out and 150 ml of diethyl ether and 150 ml of saturated NaHCO3 solution were added to the remaining solution. The phases were separated and the aqueous phase was extracted 2× using 100 ml of diethyl ether each time. The combined organic phases were washed with 2×100 ml of water and dried over Na2SO4. After removal of the solvent in vacuo, 9.58 g (78%) of tert-butyl (S)-3-amino-2-benzyloxycarbonylaminopropionate were obtained as a pale yellow oil.

Provenance & Evidence