反应详情

A solution of 12.0 g (51.7 mmol) of (S)-3,3-dimethyl-2-(1-phenylethylimino)-butyramide in 200 ml of methanol was hydrogenated in a low pressure hydrogenation apparatus in the presence of 2.0 g of 5 percent Pd/C at 40° C. and normal pressure for 6.5 hours. After cooling the catalyst was filtered off and the filtrate was evaporated to dryness: 6.7 g (99.5%) of white crystals containing 90.8% (S)-tert-leucinamide, 97.0% e.e. Recrystallization from 40 ml of cyclohexane yielded 5.3 g (78.5%) of (S)-tert-leucinamide as white crystals, m.p. 104°-105° C., [α]=-23.2 (c=1, CHCl3), 96.9% e.e.

1. temperatureAfter cooling the catalyst
2. filtrationwas filtered off
3. customthe filtrate was evaporated to dryness
4. addition6.7 g (99.5%) of white crystals containing 90.8% (S)-tert-leucinamide, 97.0% e.e
5. customRecrystallization from 40 ml of cyclohexane