Uses
(R)-3-Benzyloxy-Pyrrolidine Hydrochloride is an important organic reagent that can be used as a building block for the synthesis of many organic compounds, such as (R)-ethyl 4-(3-(benzyloxy)pyrrolidin-1-yl)butanoate.
Synthesis
After N-tert-butoxycarbonyl-(R)-3-benzyloxypyrrolidine separately obtained was dissolved in isopropanol and heated to 40 °C, isopropanol solution of hydrogen chloride was dropped for 6 hours. After the reaction finished, the mixture was cooled to 23 °C and was concentrated to distil the solvent away. Further, ethyl acetate was added and the mixture was concentrated, thereby obtaining a concentrate in an amount of about. Then, the concentrate was heated to 40 °C, and isopropanol was added until (R)-3-benzyloxypyrrolidine hydrochloride which had been separated as an oily substance became completely dissolved. After (R) -3-benzyloxypyrrolidine hydrochloride was crystallized by gradually cooling the solution and suitably adding a seed crystal, hexane was further added. At the time, crystallization solvent was in a following proportion: isopropanol/ethyl acetate/hexane = 1/71.5/71.5. A deposited crystal was subjected to filtration under reduced pressure, and the resultant wet crystal was washed with ethyl acetate, and then a wet crystal was dried under reduced pressure, thereby obtaining dry crystal of (R)-3-benzyloxypyrrolidine hydrochloride (yield of 82 %, purity of 99.8 %).
