反应详情

Methyl 2-(3-cyclohexyl-1,1,1-trifluoro-3-nitropropan-2-ylamino)-3,3-dimethylbutanoate (5A-1) (0.553 gm) in ethanol (70 mL) was hydrogenated over Raney Nickel catalyst at 50 psi for 16 hours. The catalyst was filtered off and the filtrate was evaporated to dryness under reduced pressure, to give crude methyl 2-(3-amino-3-cyclohexyl-1,1,1-trifluoropropan-2-ylamino)-3,3-dimethylbutanoate (6). Separation by silica gel chromatography, eluting with 10% ethyl acetate/hexane, gave two pure isomers, a faster eluting compound, 6A1-isomer A (389 mgm) and a slower eluting compound, 6A1-isomer B (57 mgm). The two compounds are different stereoisomers of methyl 2-(3-cyclohexyl-1,1,1-trifluoro-3-aminopropan-2-ylamino)-3,3-dimethylbutanoate, although the absolute stereochemistry has not yet been established.

1. filtrationThe catalyst was filtered off
2. customthe filtrate was evaporated to dryness under reduced pressure