Hydrazine → tert-butyl N-(2-aminoethyl)-3-methyl-L-valinate

Participants

Reaction Conditions

Reaction Steps

The product of Example 111-2 (87 g, 241.6 mmol) was taken up in ethanol (2 L) in a 3-necked, 3L round bottom flask equipped with mechanical stirring under N2. Hydrazine (anhydrous, 68.3 mL, 2.17 mol, 9 equivalents) was added. The reaction mixture was heated to 75° C., which resulted in the formation of a very thick suspension. The addition of more ethanol was necessary in order to continue effective stirring. The reaction was stirred for 1 hour at 75° C. until consumption of starting material was complete as determined by HPLC. The thick suspension was cooled to ambient temperature and quenched with 1 L of 0.5N NaOH solution. The mixture was diluted with 0.5N NaOH (2 L) and extracted with dichloromethane (2×2 L). The combined organic layer was washed with brine (1 L), dried over MgSO4, filtered and concentrated to oil. The oil was chased with heptanes to remove ethanol and pump dried to afford light yellow oil (50.2 g, 93.2% yield). 1H NMR (CDCl3): δ 2.73(m, 4H), 2.45(m, 1H), 1.64(s, 9H), 0.96(s, 9H).

Provenance & Evidence