反应详情

To a solution of (S)-3,3-Dimethyl-2-(2,2,2-trifluoro-1,1-dimethyl-ethoxycarbonylamino)-butyric acid methyl ester (673 mg, 2.249 mmol, from Step 1b) in THF (4 mL) was added to a pre-made solution of lithium hydroxide monohydrate (189 mg, 4.50 mmol) in water (4.00 mL). The cloudy white solution was stirred at rt for 5 hrs. Another 100 mg of LiOH in 1 mL water was added to the mixture and the solution was stirred at rt overnight. The volatiles were removed, and the reaction mixture was diluted with 5% citric acid aqueous solution, and extracted with EtOAc (3×10 mL). The organic layer was washed with brine, dried over Na2SO4, filtered and evaporated. The crude material (325 mg, 51%) as white solid was used in the next step reaction without further purification.

1. stirringthe solution was stirred at rt overnight
2. customThe volatiles were removed
3. additionthe reaction mixture was diluted with 5% citric acid aqueous solution
4. extractionextracted with EtOAc (3×10 mL)
5. washThe organic layer was washed with brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. customevaporated
9. customThe crude material (325 mg, 51%) as white solid was used in the next step reaction without further purification