反应详情

To a solution of (2R)-2-[(tert-butoxycarbonyl)amino]-3-[4-(trifluoromethyl)phenyl]propanoic acid XXI (1 g, 3 mmol) in dry THF (10 mL) was added sodium hydride (60% suspension in mineral oil) (0.72 g, 18 mmol; 6 eq. of pure NaH) in portions. Methyl iodide (1.12 mL, 18 mmol) was then added and the mixture was stirring at r.t. for 3 days. The mixture was then treated with water before removing the THF under reduced pressure. The aqueous phase was acidified and extracted 2× EtOAc. The combined EtOAc was washed with sodium thiosulfate, dried and evaporated under reduced pressure. The residue was crystallized to produce (2R)-2-[(tert-butoxycarbonyl)(methyl)amino]-3-[4-(trifluoromethyl)phenyl]-propanoic acid XXII (0.73 g, 2 mmol, 70% yield).

1. custombefore removing the THF under reduced pressure
2. extractionextracted 2× EtOAc
3. washThe combined EtOAc was washed with sodium thiosulfate
4. customdried
5. customevaporated under reduced pressure
6. customThe residue was crystallized