反应详情

To a solution of 5.15 g (20 mmol) 4-oxo-pyrrolidine-1,3-dicarboxylic acid 1-tert. butylester 3-ethylester in 30 ml methanol was added 1.88 g (30 mmol) sodium cyanoborohydride and a small amount of methylorange. With stirring the pH was adjusted to 3 by dropwise addition of 1N hydrochloric acid (color change from yellow to orange). After no more acid was consumed the mixture was stirred for one hour. The solvent was evaporated in vacuo and the residue was partitioned between ethyl acetate and water. The organic layer was washed twice with water, then with brine, dried over magnesium sulfate and evaporated. The residual yellow oil was used in the next step without any further purification.

1. customAfter no more acid was consumed the mixture
2. stirringwas stirred for one hour
3. customThe solvent was evaporated in vacuo
4. customthe residue was partitioned between ethyl acetate and water
5. washThe organic layer was washed twice with water
6. dry with materialwith brine, dried over magnesium sulfate
7. customevaporated
8. customThe residual yellow oil was used in the next step without any further purification