1,2-Pyrrolidinedicarboxylic acid, 1-(1,1-dimethylethyl) ester, (2S)- → Boc-Pro-D-Pro-OBn

Participants

Reaction Steps

5.75 g (30.0 mmol) of EDCl was added to 60 ml of tetrahydrofuran (THF) solution of 3.23 g (15.0 mmol) of N-Boc-L-Proline (manufactured by Tokyo Chemical Industry Co., Ltd) and 3.08 g (15.0 mmol) of D-Proline benzylester, followed by stirring for 18 hours at room temperature. After a reaction mixture was concentrated under reduced pressure, the concentrate was extracted by adding water and ethyl acetate. After an organic layer was washed sequentially with a diluted hydrochloric acid, an aqueous solution of sodium hydrogen carbonate and water (one time for each), it was concentrated under reduced pressure, thereby obtaining crude amide. The obtained amide compound was purified by a silica gel column chromatography (hexane/ethyl acetate=5/1 to 1/1 (volume ratio)), thereby obtaining 4.55 g of the product with a yield of 75.4%.

Provenance & Evidence