反应详情

A solution of 205 g. (1 mol.) of N-benzylpyrrolidine-3-carboxylic acid (CA, 64 14173d) is dissolved in glacial acetic acid (1 l.) and hydrogenated in the presence of 40 g. of 10% palladium on charcoal until no more starting material is detected by TLC. The catalyst is filtered off and the filtrate is concentrated to dryness in vacuo. The residual 3-pyrrolidine carboxylic acid is dissolved in a mixture of DMF-H2O (2:1) (2 liters), triethylamine (1 mol.), t-butoxycarbonyl azide (1.5 mol.) is added and the mixture is stirred at room temperature for two days. Periodically the pH is tested with pH paper, and after twenty-four hours more azide (0.5 mol.) is added. The solvent is concentrated in vacuo to remove the DMF, the aqueous phase is acidified with citric acid (to pH 2-3) and extracted with ethyl acetate. The organic phase is concentrated to dryness in vacuo to yield the product 1-(t-butyloxycarbonyl)-3-pyrrolidinecarboxylic acid.

1. filtrationThe catalyst is filtered off
2. concentrationthe filtrate is concentrated to dryness in vacuo
3. additionis added
4. concentrationThe solvent is concentrated in vacuo
5. customto remove the DMF
6. extractionextracted with ethyl acetate
7. concentrationThe organic phase is concentrated to dryness in vacuo