(S)-N-tert-butyl-3,3-dimethyl-2-(1-phenylethylimino)-butyramide → (S)-N-tert-butyl-tert-leucinamide

Participants

Reaction Steps

A solution of 20.0 g (69.3 mmol) of (S)-N-tert-butyl-3,3-dimethyl-2-(1-phenylethylimino)-butyramide in 155 ml of methanol was hydrogenated in a low pressure hydrogenation apparatus in the presence of 12.5 g of 5 percent Pd/C at 40° C. and normal pressure for 51 hours. After cooling the catalyst was filtered off and the filtrate was evaporated to dryness: 11.9 g (92.2%) of white crystals containing 94.4% (S)-N-tert-butyl-tert-leucinamide, 92.5% e.e. Recrystallization from 50 ml of hexane yielded 7.8 g (66.0%) of (S)-N-tert-butyl-tert-leucinamide as white crystals, m.p. 78°-80° C., [α]=-32.2 (c=1, CHCl3), >98% e.e.

Provenance & Evidence