2-Amino-4-methylpentanamide hydrochloride → 1,2-Diamino-4-methylpentane dihydrochloride

Beteiligte Stoffe

Reaktionsschritte

To a stirred slurry of D,L-leucine amide hydrochloride (50.0 g, 0.300 mole) in anhydrous THF (500 ml) at room temperature under a dry argon atmosphere was added a solution of lithium aluminum hydride (1200 ml--1.0M in THF, 1.20 mole) over a 15 minute period. The mixture was refluxed for 8 h and then quenched by the dropwise addition of H2O (200 ml) while cooling in an ice bath. The mixture was filtered to remove solid and the filtrate was retained. The solid was washed with THF (100 ml) and slurried in hot THF (2×1.0 l). The THF filtrates and washings were combined and the solid was discarded. The THF solution was acidified to pH 1 with concentrated HCl. The solvent was removed in vacuo to give a pale yellow oil. The oil was dissolved in ethanol and the solvent was removed in vacuo to give an oil which crystallized. The crude material was purified by recrystallization from MeOH-ethyl ether to give 42.3 g (75% yield) of the product as a white crystalline solid: mp 228-30° C.; 1H NMR (DMSO-d6) δ 0.89 (d, J=6.5 Hz, 3 H), 0.90 (d, J=6.5 Hz, 3 H), 1.51 (t, J=7.2 Hz, 2 H), 1.75 (Sept, J=6.7 Hz, 1 H), 3.08 (m, 2 H), 3.49 (m, 1 H).

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