反应详情

Lithium hydroxide monohydrate (469 mg, 11.2 mmol) is added to a solution of (S)-4,4-difluoro-pyrrolidine-1,2-dicarboxylic acid 1-tert-butyl ester 2-methyl ester (1.48 g, 5.59 mmol) in 3:1 acetonitrile in water (20 mL). The reaction is stirred at room temperature for 2 hours. The reaction mixture is concentrated under reduced pressure and diluted with water and extracted with ether. The aqueous layer is acidified to PH˜1 and extracted with ethyl acetate 3 times. The organics are combined and washed with brine, dried over Na2SO4, filtered and concentrated under reduced pressure to yield the title compound. ESI m/z 152 [M+H+−100].

1. concentrationThe reaction mixture is concentrated under reduced pressure
2. additiondiluted with water
3. extractionextracted with ether
4. extractionextracted with ethyl acetate 3 times
5. washwashed with brine
6. dry with materialdried over Na2SO4
7. filtrationfiltered
8. concentrationconcentrated under reduced pressure